util/linuxfw: fix IPv6 availability check for nftables (#12009)

* util/linuxfw: fix IPv6 NAT availability check for nftables

When running firewall in nftables mode,
there is no need for a separate NAT availability check
(unlike with iptables, there are no hosts that support nftables, but not IPv6 NAT - see tailscale/tailscale#11353).
This change fixes a firewall NAT availability check that was using the no-longer set ipv6NATAvailable field
by removing the field and using a method that, for nftables, just checks that IPv6 is available.

Updates tailscale/tailscale#12008

Signed-off-by: Irbe Krumina <irbe@tailscale.com>

.github/workflows/codeql-analysis.yml

@@ -47,6 +47,12 @@ jobs:
     - name: Checkout repository
       uses: actions/checkout@v4
 
+    # Install a more recent Go that understands modern go.mod content.
+    - name: Install Go
+      uses: actions/setup-go@v4
+      with:
+        go-version-file: go.mod
+
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
       uses: github/codeql-action/init@v2

.github/workflows/go-licenses.yml

@@ -1,64 +0,0 @@
-name: go-licenses
-
-on:
-  # run action when a change lands in the main branch which updates go.mod or
-  # our license template file. Also allow manual triggering.
-  push:
-    branches:
-      - main
-    paths:
-      - go.mod
-      - .github/licenses.tmpl
-      - .github/workflows/go-licenses.yml
-  workflow_dispatch:
-
-concurrency:
-  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
-  cancel-in-progress: true
-
-jobs:
-  update-licenses:
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Check out code
-        uses: actions/checkout@v4
-
-      - name: Set up Go
-        uses: actions/setup-go@v4
-        with:
-          go-version-file: go.mod
-
-      - name: Install go-licenses
-        run: |
-          go install github.com/google/go-licenses@v1.2.2-0.20220825154955-5eedde1c6584
-
-      - name: Run go-licenses
-        env:
-          # include all build tags to include platform-specific dependencies
-          GOFLAGS: "-tags=android,cgo,darwin,freebsd,ios,js,linux,openbsd,wasm,windows"
-        run: |
-          [ -d licenses ] || mkdir licenses
-          go-licenses report tailscale.com/cmd/tailscale tailscale.com/cmd/tailscaled > licenses/tailscale.md --template .github/licenses.tmpl
-
-      - name: Get access token
-        uses: tibdex/github-app-token@b62528385c34dbc9f38e5f4225ac829252d1ea92 # v1.8.0
-        id: generate-token
-        with:
-          app_id: ${{ secrets.LICENSING_APP_ID }}
-          installation_id: ${{ secrets.LICENSING_APP_INSTALLATION_ID }}
-          private_key: ${{ secrets.LICENSING_APP_PRIVATE_KEY }}
-
-      - name: Send pull request
-        uses: peter-evans/create-pull-request@284f54f989303d2699d373481a0cfa13ad5a6666 #v5.0.1
-        with:
-          token: ${{ steps.generate-token.outputs.token }}
-          author: License Updater <noreply+license-updater@tailscale.com>
-          committer: License Updater <noreply+license-updater@tailscale.com>
-          branch: licenses/cli
-          commit-message: "licenses: update tailscale{,d} licenses"
-          title: "licenses: update tailscale{,d} licenses"
-          body: Triggered by ${{ github.repository }}@${{ github.sha }}
-          signoff: true
-          delete-branch: true
-          team-reviewers: opensource-license-reviewers

.github/workflows/golangci-lint.yml

@@ -34,7 +34,7 @@ jobs:
         # Note: this is the 'v3' tag as of 2023-08-14
         uses: golangci/golangci-lint-action@639cd343e1d3b897ff35927a75193d57cfcba299
         with:
-          version: v1.54.2
+          version: v1.56
 
           # Show only new issues if it's a pull request.
           only-new-issues: true

.github/workflows/installer.yml

@@ -32,7 +32,6 @@ jobs:
           - "ubuntu:18.04"
           - "ubuntu:20.04"
           - "ubuntu:22.04"
-          - "ubuntu:22.10"
           - "ubuntu:23.04"
           - "elementary/docker:stable"
           - "elementary/docker:unstable"
@@ -91,7 +90,10 @@ jobs:
         || contains(matrix.image, 'parrotsec')
         || contains(matrix.image, 'kalilinux')
     - name: checkout
-      uses: actions/checkout@v4
+      # We cannot use v4, as it requires a newer glibc version than some of the
+      # tested images provide. See
+      # https://github.com/actions/checkout/issues/1487
+      uses: actions/checkout@v3
     - name: run installer
       run: scripts/installer.sh
       # Package installation can fail in docker because systemd is not running

.github/workflows/kubemanifests.yaml

@@ -2,8 +2,8 @@ name: "Kubernetes manifests"
 on:
   pull_request:
    paths: 
-   - './cmd/k8s-operator/'
-   - './k8s-operator/'
+   - 'cmd/k8s-operator/**'
+   - 'k8s-operator/**'
    - '.github/workflows/kubemanifests.yaml'
 
 # Cancel workflow run if there is a newer push to the same PR for which it is

.github/workflows/test.yml

@@ -183,6 +183,19 @@ jobs:
       # the equals signs cause great confusion.
       run: go test ./... -bench . -benchtime 1x -run "^$"
 
+  privileged:
+    runs-on: ubuntu-22.04
+    container:
+      image: golang:latest
+      options: --privileged
+    steps:
+    - name: checkout
+      uses: actions/checkout@v4
+    - name: chown
+      run: chown -R $(id -u):$(id -g) $PWD
+    - name: privileged tests
+      run: ./tool/go test ./util/linuxfw
+
   vm:
     runs-on: ["self-hosted", "linux", "vm"]
     # VM tests run with some privileges, don't let them run on 3p PRs.
@@ -193,9 +206,9 @@ jobs:
     - name: Run VM tests
       run: ./tool/go test ./tstest/integration/vms -v -no-s3 -run-vm-tests -run=TestRunUbuntu2004
       env:
-        HOME: "/tmp"
+        HOME: "/var/lib/ghrunner/home"
         TMPDIR: "/tmp"
-        XDB_CACHE_HOME: "/var/lib/ghrunner/cache"
+        XDG_CACHE_HOME: "/var/lib/ghrunner/cache"
 
   race-build:
     runs-on: ubuntu-22.04
@@ -241,9 +254,6 @@ jobs:
             goarch: amd64
           - goos: openbsd
             goarch: amd64
-          # Plan9
-          - goos: plan9
-            goarch: amd64
 
     runs-on: ubuntu-22.04
     steps:
@@ -292,6 +302,47 @@ jobs:
         GOOS: ios
         GOARCH: arm64
 
+  crossmin: # cross-compile for platforms where we only check cmd/tailscale{,d}
+    strategy:
+      fail-fast: false # don't abort the entire matrix if one element fails
+      matrix:
+        include:
+          # Plan9
+          - goos: plan9
+            goarch: amd64
+          # AIX
+          - goos: aix
+            goarch: ppc64
+
+    runs-on: ubuntu-22.04
+    steps:
+    - name: checkout
+      uses: actions/checkout@v4
+    - name: Restore Cache
+      uses: actions/cache@v3
+      with:
+        # Note: unlike the other setups, this is only grabbing the mod download
+        # cache, rather than the whole mod directory, as the download cache
+        # contains zips that can be unpacked in parallel faster than they can be
+        # fetched and extracted by tar
+        path: |
+          ~/.cache/go-build
+          ~/go/pkg/mod/cache
+          ~\AppData\Local\go-build
+        # The -2- here should be incremented when the scheme of data to be
+        # cached changes (e.g. path above changes).
+        key: ${{ github.job }}-${{ runner.os }}-${{ matrix.goos }}-${{ matrix.goarch }}-go-2-${{ hashFiles('**/go.sum') }}-${{ github.run_id }}
+        restore-keys: |
+          ${{ github.job }}-${{ runner.os }}-${{ matrix.goos }}-${{ matrix.goarch }}-go-2-${{ hashFiles('**/go.sum') }}
+          ${{ github.job }}-${{ runner.os }}-${{ matrix.goos }}-${{ matrix.goarch }}-go-2-
+    - name: build core
+      run: ./tool/go build ./cmd/tailscale ./cmd/tailscaled
+      env:
+        GOOS: ${{ matrix.goos }}
+        GOARCH: ${{ matrix.goarch }}
+        GOARM: ${{ matrix.goarm }}
+        CGO_ENABLED: "0"
+
   android:
     # similar to cross above, but android fails to build a few pieces of the
     # repo. We should fix those pieces, they're small, but as a stepping stone,
@@ -305,7 +356,7 @@ jobs:
       # some Android breakages early.
       # TODO(bradfitz): better; see https://github.com/tailscale/tailscale/issues/4482
     - name: build some
-      run: ./tool/go install ./net/netns ./ipn/ipnlocal ./wgengine/magicsock/ ./wgengine/ ./wgengine/router/ ./wgengine/netstack ./util/dnsname/ ./ipn/ ./net/interfaces ./wgengine/router/ ./tailcfg/ ./types/logger/ ./net/dns ./hostinfo ./version
+      run: ./tool/go install ./net/netns ./ipn/ipnlocal ./wgengine/magicsock/ ./wgengine/ ./wgengine/router/ ./wgengine/netstack ./util/dnsname/ ./ipn/ ./net/netmon ./wgengine/router/ ./tailcfg/ ./types/logger/ ./net/dns ./hostinfo ./version
       env:
         GOOS: android
         GOARCH: arm64

.gitignore

@@ -9,6 +9,7 @@
 
 cmd/tailscale/tailscale
 cmd/tailscaled/tailscaled
+ssh/tailssh/testcontainers/tailscaled
 
 # Test binary, built with `go test -c`
 *.test

Dockerfile

@@ -31,7 +31,7 @@
 #     $ docker exec tailscaled tailscale status
 
 
-FROM golang:1.21-alpine AS build-env
+FROM golang:1.22-alpine AS build-env
 
 WORKDIR /go/src/tailscale
 

Makefile

@@ -1,5 +1,5 @@
 IMAGE_REPO ?= tailscale/tailscale
-SYNO_ARCH ?= "amd64"
+SYNO_ARCH ?= "x86_64"
 SYNO_DSM ?= "7"
 TAGS ?= "latest"
 
@@ -100,6 +100,26 @@ publishdevoperator: ## Build and publish k8s-operator image to location specifie
 	@test "${REPO}" != "ghcr.io/tailscale/k8s-operator" || (echo "REPO=... must not be ghcr.io/tailscale/k8s-operator" && exit 1)
 	TAGS="${TAGS}" REPOS=${REPO} PLATFORM=${PLATFORM} PUSH=true TARGET=operator ./build_docker.sh
 
+publishdevnameserver: ## Build and publish k8s-nameserver image to location specified by ${REPO}
+	@test -n "${REPO}" || (echo "REPO=... required; e.g. REPO=ghcr.io/${USER}/tailscale" && exit 1)
+	@test "${REPO}" != "tailscale/tailscale" || (echo "REPO=... must not be tailscale/tailscale" && exit 1)
+	@test "${REPO}" != "ghcr.io/tailscale/tailscale" || (echo "REPO=... must not be ghcr.io/tailscale/tailscale" && exit 1)
+	@test "${REPO}" != "tailscale/k8s-nameserver" || (echo "REPO=... must not be tailscale/k8s-nameserver" && exit 1)
+	@test "${REPO}" != "ghcr.io/tailscale/k8s-nameserver" || (echo "REPO=... must not be ghcr.io/tailscale/k8s-nameserver" && exit 1)
+	TAGS="${TAGS}" REPOS=${REPO} PLATFORM=${PLATFORM} PUSH=true TARGET=k8s-nameserver ./build_docker.sh
+
+.PHONY: sshintegrationtest
+sshintegrationtest: ## Run the SSH integration tests in various Docker containers
+	@GOOS=linux GOARCH=amd64 go test -tags integrationtest -c ./ssh/tailssh -o ssh/tailssh/testcontainers/tailssh.test && \
+	GOOS=linux GOARCH=amd64 go build -o ssh/tailssh/testcontainers/tailscaled ./cmd/tailscaled && \
+	echo "Testing on ubuntu:focal" && docker build --build-arg="BASE=ubuntu:focal" -t ssh-ubuntu-focal ssh/tailssh/testcontainers && \
+	echo "Testing on ubuntu:jammy" && docker build --build-arg="BASE=ubuntu:jammy" -t ssh-ubuntu-jammy ssh/tailssh/testcontainers && \
+	echo "Testing on ubuntu:mantic" && docker build --build-arg="BASE=ubuntu:mantic" -t ssh-ubuntu-mantic ssh/tailssh/testcontainers && \
+	echo "Testing on ubuntu:noble" && docker build --build-arg="BASE=ubuntu:noble" -t ssh-ubuntu-noble ssh/tailssh/testcontainers && \
+	echo "Testing on fedora:38" && docker build --build-arg="BASE=dokken/fedora-38" -t ssh-fedora-38 ssh/tailssh/testcontainers && \
+	echo "Testing on fedora:39" && docker build --build-arg="BASE=dokken/fedora-39" -t ssh-fedora-39 ssh/tailssh/testcontainers && \
+	echo "Testing on fedora:40" && docker build --build-arg="BASE=dokken/fedora-40" -t ssh-fedora-40 ssh/tailssh/testcontainers
+
 help: ## Show this help
 	@echo "\nSpecify a command. The choices are:\n"
 	@grep -hE '^[0-9a-zA-Z_-]+:.*?## .*$$' ${MAKEFILE_LIST} | awk 'BEGIN {FS = ":.*?## "}; {printf "  \033[0;36m%-20s\033[m %s\n", $$1, $$2}'

README.md

@@ -37,7 +37,7 @@ not open source.
 
 ## Building
 
-We always require the latest Go release, currently Go 1.21. (While we build
+We always require the latest Go release, currently Go 1.22. (While we build
 releases with our [Go fork](https://github.com/tailscale/go/), its use is not
 required.)
 

VERSION.txt

@@ -1 +1 @@
-1.57.0
+1.67.0

appc/appconnector.go

@@ -10,6 +10,7 @@
 package appc
 
 import (
+	"context"
 	"net/netip"
 	"slices"
 	"strings"
@@ -20,17 +21,33 @@ import (
 	"tailscale.com/types/logger"
 	"tailscale.com/types/views"
 	"tailscale.com/util/dnsname"
+	"tailscale.com/util/execqueue"
+	"tailscale.com/util/mak"
+	"tailscale.com/util/slicesx"
 )
 
 // RouteAdvertiser is an interface that allows the AppConnector to advertise
 // newly discovered routes that need to be served through the AppConnector.
 type RouteAdvertiser interface {
-	// AdvertiseRoute adds a new route advertisement if the route is not already
-	// being advertised.
-	AdvertiseRoute(netip.Prefix) error
+	// AdvertiseRoute adds one or more route advertisements skipping any that
+	// are already advertised.
+	AdvertiseRoute(...netip.Prefix) error
 
-	// UnadvertiseRoute removes a route advertisement.
-	UnadvertiseRoute(netip.Prefix) error
+	// UnadvertiseRoute removes any matching route advertisements.
+	UnadvertiseRoute(...netip.Prefix) error
+}
+
+// RouteInfo is a data structure used to persist the in memory state of an AppConnector
+// so that we can know, even after a restart, which routes came from ACLs and which were
+// learned from domains.
+type RouteInfo struct {
+	// Control is the routes from the 'routes' section of an app connector acl.
+	Control []netip.Prefix `json:",omitempty"`
+	// Domains are the routes discovered by observing DNS lookups for configured domains.
+	Domains map[string][]netip.Addr `json:",omitempty"`
+	// Wildcards are the configured DNS lookup domains to observe. When a DNS query matches Wildcards,
+	// its result is added to Domains.
+	Wildcards []string `json:",omitempty"`
 }
 
 // AppConnector is an implementation of an AppConnector that performs
@@ -46,11 +63,14 @@ type AppConnector struct {
 	logf            logger.Logf
 	routeAdvertiser RouteAdvertiser
 
+	// storeRoutesFunc will be called to persist routes if it is not nil.
+	storeRoutesFunc func(*RouteInfo) error
+
 	// mu guards the fields that follow
 	mu sync.Mutex
 
-	// domains is a map of lower case domain names with no trailing dot, to a
-	// list of resolved IP addresses.
+	// domains is a map of lower case domain names with no trailing dot, to an
+	// ordered list of resolved IP addresses.
 	domains map[string][]netip.Addr
 
 	// controlRoutes is the list of routes that were last supplied by control.
@@ -58,21 +78,81 @@ type AppConnector struct {
 
 	// wildcards is the list of domain strings that match subdomains.
 	wildcards []string
+
+	// queue provides ordering for update operations
+	queue execqueue.ExecQueue
 }
 
 // NewAppConnector creates a new AppConnector.
-func NewAppConnector(logf logger.Logf, routeAdvertiser RouteAdvertiser) *AppConnector {
-	return &AppConnector{
+func NewAppConnector(logf logger.Logf, routeAdvertiser RouteAdvertiser, routeInfo *RouteInfo, storeRoutesFunc func(*RouteInfo) error) *AppConnector {
+	ac := &AppConnector{
 		logf:            logger.WithPrefix(logf, "appc: "),
 		routeAdvertiser: routeAdvertiser,
+		storeRoutesFunc: storeRoutesFunc,
 	}
+	if routeInfo != nil {
+		ac.domains = routeInfo.Domains
+		ac.wildcards = routeInfo.Wildcards
+		ac.controlRoutes = routeInfo.Control
+	}
+	return ac
 }
 
-// UpdateDomains replaces the current set of configured domains with the
-// supplied set of domains. Domains must not contain a trailing dot, and should
-// be lower case. If the domain contains a leading '*' label it matches all
-// subdomains of a domain.
+// ShouldStoreRoutes returns true if the appconnector was created with the controlknob on
+// and is storing its discovered routes persistently.
+func (e *AppConnector) ShouldStoreRoutes() bool {
+	return e.storeRoutesFunc != nil
+}
+
+// storeRoutesLocked takes the current state of the AppConnector and persists it
+func (e *AppConnector) storeRoutesLocked() error {
+	if !e.ShouldStoreRoutes() {
+		return nil
+	}
+	return e.storeRoutesFunc(&RouteInfo{
+		Control:   e.controlRoutes,
+		Domains:   e.domains,
+		Wildcards: e.wildcards,
+	})
+}
+
+// ClearRoutes removes all route state from the AppConnector.
+func (e *AppConnector) ClearRoutes() error {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	e.controlRoutes = nil
+	e.domains = nil
+	e.wildcards = nil
+	return e.storeRoutesLocked()
+}
+
+// UpdateDomainsAndRoutes starts an asynchronous update of the configuration
+// given the new domains and routes.
+func (e *AppConnector) UpdateDomainsAndRoutes(domains []string, routes []netip.Prefix) {
+	e.queue.Add(func() {
+		// Add the new routes first.
+		e.updateRoutes(routes)
+		e.updateDomains(domains)
+	})
+}
+
+// UpdateDomains asynchronously replaces the current set of configured domains
+// with the supplied set of domains. Domains must not contain a trailing dot,
+// and should be lower case. If the domain contains a leading '*' label it
+// matches all subdomains of a domain.
 func (e *AppConnector) UpdateDomains(domains []string) {
+	e.queue.Add(func() {
+		e.updateDomains(domains)
+	})
+}
+
+// Wait waits for the currently scheduled asynchronous configuration changes to
+// complete.
+func (e *AppConnector) Wait(ctx context.Context) {
+	e.queue.Wait(ctx)
+}
+
+func (e *AppConnector) updateDomains(domains []string) {
 	e.mu.Lock()
 	defer e.mu.Unlock()
 
@@ -97,18 +177,34 @@ func (e *AppConnector) UpdateDomains(domains []string) {
 		for _, wc := range e.wildcards {
 			if dnsname.HasSuffix(d, wc) {
 				e.domains[d] = addrs
+				delete(oldDomains, d)
 				break
 			}
 		}
 	}
+
+	// Everything left in oldDomains is a domain we're no longer tracking
+	// and if we are storing route info we can unadvertise the routes
+	if e.ShouldStoreRoutes() {
+		toRemove := []netip.Prefix{}
+		for _, addrs := range oldDomains {
+			for _, a := range addrs {
+				toRemove = append(toRemove, netip.PrefixFrom(a, a.BitLen()))
+			}
+		}
+		if err := e.routeAdvertiser.UnadvertiseRoute(toRemove...); err != nil {
+			e.logf("failed to unadvertise routes on domain removal: %v: %v: %v", xmaps.Keys(oldDomains), toRemove, err)
+		}
+	}
+
 	e.logf("handling domains: %v and wildcards: %v", xmaps.Keys(e.domains), e.wildcards)
 }
 
-// UpdateRoutes merges the supplied routes into the currently configured routes. The routes supplied
+// updateRoutes merges the supplied routes into the currently configured routes. The routes supplied
 // by control for UpdateRoutes are supplemental to the routes discovered by DNS resolution, but are
 // also more often whole ranges. UpdateRoutes will remove any single address routes that are now
 // covered by new ranges.
-func (e *AppConnector) UpdateRoutes(routes []netip.Prefix) {
+func (e *AppConnector) updateRoutes(routes []netip.Prefix) {
 	e.mu.Lock()
 	defer e.mu.Unlock()
 
@@ -117,27 +213,42 @@ func (e *AppConnector) UpdateRoutes(routes []netip.Prefix) {
 		return
 	}
 
+	if err := e.routeAdvertiser.AdvertiseRoute(routes...); err != nil {
+		e.logf("failed to advertise routes: %v: %v", routes, err)
+		return
+	}
+
+	var toRemove []netip.Prefix
+
+	// If we're storing routes and know e.controlRoutes is a good
+	// representation of what should be in AdvertisedRoutes we can stop
+	// advertising routes that used to be in e.controlRoutes but are not
+	// in routes.
+	if e.ShouldStoreRoutes() {
+		toRemove = routesWithout(e.controlRoutes, routes)
+	}
+
 nextRoute:
 	for _, r := range routes {
-		if err := e.routeAdvertiser.AdvertiseRoute(r); err != nil {
-			e.logf("failed to advertise route: %v: %v", r, err)
-			continue
-		}
-
 		for _, addr := range e.domains {
 			for _, a := range addr {
-				if r.Contains(a) {
+				if r.Contains(a) && netip.PrefixFrom(a, a.BitLen()) != r {
 					pfx := netip.PrefixFrom(a, a.BitLen())
-					if err := e.routeAdvertiser.UnadvertiseRoute(pfx); err != nil {
-						e.logf("failed to unadvertise route: %v: %v", pfx, err)
-					}
+					toRemove = append(toRemove, pfx)
 					continue nextRoute
 				}
 			}
 		}
 	}
 
+	if err := e.routeAdvertiser.UnadvertiseRoute(toRemove...); err != nil {
+		e.logf("failed to unadvertise routes: %v: %v", toRemove, err)
+	}
+
 	e.controlRoutes = routes
+	if err := e.storeRoutesLocked(); err != nil {
+		e.logf("failed to store route info: %v", err)
+	}
 }
 
 // Domains returns the currently configured domain list.
@@ -175,7 +286,16 @@ func (e *AppConnector) ObserveDNSResponse(res []byte) {
 		return
 	}
 
-nextAnswer:
+	// cnameChain tracks a chain of CNAMEs for a given query in order to reverse
+	// a CNAME chain back to the original query for flattening. The keys are
+	// CNAME record targets, and the value is the name the record answers, so
+	// for www.example.com CNAME example.com, the map would contain
+	// ["example.com"] = "www.example.com".
+	var cnameChain map[string]string
+
+	// addressRecords is a list of address records found in the response.
+	var addressRecords map[string][]netip.Addr
+
 	for {
 		h, err := p.AnswerHeader()
 		if err == dnsmessage.ErrSectionDone {
@@ -191,83 +311,186 @@ nextAnswer:
 			}
 			continue
 		}
-		if h.Type != dnsmessage.TypeA && h.Type != dnsmessage.TypeAAAA {
+
+		switch h.Type {
+		case dnsmessage.TypeCNAME, dnsmessage.TypeA, dnsmessage.TypeAAAA:
+		default:
 			if err := p.SkipAnswer(); err != nil {
 				return
 			}
 			continue
+
 		}
 
-		domain := h.Name.String()
+		domain := strings.TrimSuffix(strings.ToLower(h.Name.String()), ".")
 		if len(domain) == 0 {
-			return
-		}
-		domain = strings.TrimSuffix(domain, ".")
-		domain = strings.ToLower(domain)
-		e.logf("[v2] observed DNS response for %s", domain)
-
-		e.mu.Lock()
-		addrs, ok := e.domains[domain]
-		// match wildcard domains
-		if !ok {
-			for _, wc := range e.wildcards {
-				if dnsname.HasSuffix(domain, wc) {
-					e.domains[domain] = nil
-					ok = true
-					break
-				}
-			}
-		}
-		e.mu.Unlock()
-
-		if !ok {
-			if err := p.SkipAnswer(); err != nil {
-				return
-			}
 			continue
 		}
 
-		var addr netip.Addr
+		if h.Type == dnsmessage.TypeCNAME {
+			res, err := p.CNAMEResource()
+			if err != nil {
+				return
+			}
+			cname := strings.TrimSuffix(strings.ToLower(res.CNAME.String()), ".")
+			if len(cname) == 0 {
+				continue
+			}
+			mak.Set(&cnameChain, cname, domain)
+			continue
+		}
+
 		switch h.Type {
 		case dnsmessage.TypeA:
 			r, err := p.AResource()
 			if err != nil {
 				return
 			}
-			addr = netip.AddrFrom4(r.A)
+			addr := netip.AddrFrom4(r.A)
+			mak.Set(&addressRecords, domain, append(addressRecords[domain], addr))
 		case dnsmessage.TypeAAAA:
 			r, err := p.AAAAResource()
 			if err != nil {
 				return
 			}
-			addr = netip.AddrFrom16(r.AAAA)
+			addr := netip.AddrFrom16(r.AAAA)
+			mak.Set(&addressRecords, domain, append(addressRecords[domain], addr))
 		default:
 			if err := p.SkipAnswer(); err != nil {
 				return
 			}
 			continue
 		}
-		if slices.Contains(addrs, addr) {
+	}
+
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
+	for domain, addrs := range addressRecords {
+		domain, isRouted := e.findRoutedDomainLocked(domain, cnameChain)
+
+		// domain and none of the CNAMEs in the chain are routed
+		if !isRouted {
 			continue
 		}
-		for _, route := range e.controlRoutes {
-			if route.Contains(addr) {
-				// record the new address associated with the domain for faster matching in subsequent
-				// requests and for diagnostic records.
-				e.mu.Lock()
-				e.domains[domain] = append(addrs, addr)
-				e.mu.Unlock()
-				continue nextAnswer
+
+		// advertise each address we have learned for the routed domain, that
+		// was not already known.
+		var toAdvertise []netip.Prefix
+		for _, addr := range addrs {
+			if !e.isAddrKnownLocked(domain, addr) {
+				toAdvertise = append(toAdvertise, netip.PrefixFrom(addr, addr.BitLen()))
 			}
 		}
-		if err := e.routeAdvertiser.AdvertiseRoute(netip.PrefixFrom(addr, addr.BitLen())); err != nil {
-			e.logf("failed to advertise route for %s: %v: %v", domain, addr, err)
-			continue
-		}
-		e.logf("[v2] advertised route for %v: %v", domain, addr)
 
-		e.mu.Lock()
-		e.domains[domain] = append(addrs, addr)
-		e.mu.Unlock()
+		e.logf("[v2] observed new routes for %s: %s", domain, toAdvertise)
+		e.scheduleAdvertisement(domain, toAdvertise...)
 	}
 }
+
+// starting from the given domain that resolved to an address, find it, or any
+// of the domains in the CNAME chain toward resolving it, that are routed
+// domains, returning the routed domain name and a bool indicating whether a
+// routed domain was found.
+// e.mu must be held.
+func (e *AppConnector) findRoutedDomainLocked(domain string, cnameChain map[string]string) (string, bool) {
+	var isRouted bool
+	for {
+		_, isRouted = e.domains[domain]
+		if isRouted {
+			break
+		}
+
+		// match wildcard domains
+		for _, wc := range e.wildcards {
+			if dnsname.HasSuffix(domain, wc) {
+				e.domains[domain] = nil
+				isRouted = true
+				break
+			}
+		}
+
+		next, ok := cnameChain[domain]
+		if !ok {
+			break
+		}
+		domain = next
+	}
+	return domain, isRouted
+}
+
+// isAddrKnownLocked returns true if the address is known to be associated with
+// the given domain. Known domain tables are updated for covered routes to speed
+// up future matches.
+// e.mu must be held.
+func (e *AppConnector) isAddrKnownLocked(domain string, addr netip.Addr) bool {
+	if e.hasDomainAddrLocked(domain, addr) {
+		return true
+	}
+	for _, route := range e.controlRoutes {
+		if route.Contains(addr) {
+			// record the new address associated with the domain for faster matching in subsequent
+			// requests and for diagnostic records.
+			e.addDomainAddrLocked(domain, addr)
+			return true
+		}
+	}
+	return false
+}
+
+// scheduleAdvertisement schedules an advertisement of the given address
+// associated with the given domain.
+func (e *AppConnector) scheduleAdvertisement(domain string, routes ...netip.Prefix) {
+	e.queue.Add(func() {
+		if err := e.routeAdvertiser.AdvertiseRoute(routes...); err != nil {
+			e.logf("failed to advertise routes for %s: %v: %v", domain, routes, err)
+			return
+		}
+		e.mu.Lock()
+		defer e.mu.Unlock()
+
+		for _, route := range routes {
+			if !route.IsSingleIP() {
+				continue
+			}
+			addr := route.Addr()
+			if !e.hasDomainAddrLocked(domain, addr) {
+				e.addDomainAddrLocked(domain, addr)
+				e.logf("[v2] advertised route for %v: %v", domain, addr)
+			}
+		}
+		if err := e.storeRoutesLocked(); err != nil {
+			e.logf("failed to store route info: %v", err)
+		}
+	})
+}
+
+// hasDomainAddrLocked returns true if the address has been observed in a
+// resolution of domain.
+func (e *AppConnector) hasDomainAddrLocked(domain string, addr netip.Addr) bool {
+	_, ok := slices.BinarySearchFunc(e.domains[domain], addr, compareAddr)
+	return ok
+}
+
+// addDomainAddrLocked adds the address to the list of addresses resolved for
+// domain and ensures the list remains sorted. Does not attempt to deduplicate.
+func (e *AppConnector) addDomainAddrLocked(domain string, addr netip.Addr) {
+	e.domains[domain] = append(e.domains[domain], addr)
+	slices.SortFunc(e.domains[domain], compareAddr)
+}
+
+func compareAddr(l, r netip.Addr) int {
+	return l.Compare(r)
+}
+
+// routesWithout returns a without b where a and b
+// are unsorted slices of netip.Prefix
+func routesWithout(a, b []netip.Prefix) []netip.Prefix {
+	m := make(map[netip.Prefix]bool, len(b))
+	for _, p := range b {
+		m[p] = true
+	}
+	return slicesx.Filter(make([]netip.Prefix, 0, len(a)), a, func(p netip.Prefix) bool {
+		return !m[p]
+	})
+}

appc/appconnector_test.go

@@ -4,6 +4,7 @@
 package appc
 
 import (
+	"context"
 	"net/netip"
 	"reflect"
 	"slices"
@@ -11,140 +12,243 @@ import (
 
 	xmaps "golang.org/x/exp/maps"
 	"golang.org/x/net/dns/dnsmessage"
+	"tailscale.com/appc/appctest"
 	"tailscale.com/util/mak"
 	"tailscale.com/util/must"
 )
 
+func fakeStoreRoutes(*RouteInfo) error { return nil }
+
 func TestUpdateDomains(t *testing.T) {
-	a := NewAppConnector(t.Logf, nil)
-	a.UpdateDomains([]string{"example.com"})
-	if got, want := a.Domains().AsSlice(), []string{"example.com"}; !slices.Equal(got, want) {
-		t.Errorf("got %v; want %v", got, want)
-	}
+	for _, shouldStore := range []bool{false, true} {
+		ctx := context.Background()
+		var a *AppConnector
+		if shouldStore {
+			a = NewAppConnector(t.Logf, &appctest.RouteCollector{}, &RouteInfo{}, fakeStoreRoutes)
+		} else {
+			a = NewAppConnector(t.Logf, &appctest.RouteCollector{}, nil, nil)
+		}
+		a.UpdateDomains([]string{"example.com"})
 
-	addr := netip.MustParseAddr("192.0.0.8")
-	a.domains["example.com"] = append(a.domains["example.com"], addr)
-	a.UpdateDomains([]string{"example.com"})
+		a.Wait(ctx)
+		if got, want := a.Domains().AsSlice(), []string{"example.com"}; !slices.Equal(got, want) {
+			t.Errorf("got %v; want %v", got, want)
+		}
 
-	if got, want := a.domains["example.com"], []netip.Addr{addr}; !slices.Equal(got, want) {
-		t.Errorf("got %v; want %v", got, want)
-	}
+		addr := netip.MustParseAddr("192.0.0.8")
+		a.domains["example.com"] = append(a.domains["example.com"], addr)
+		a.UpdateDomains([]string{"example.com"})
+		a.Wait(ctx)
 
-	// domains are explicitly downcased on set.
-	a.UpdateDomains([]string{"UP.EXAMPLE.COM"})
-	if got, want := xmaps.Keys(a.domains), []string{"up.example.com"}; !slices.Equal(got, want) {
-		t.Errorf("got %v; want %v", got, want)
+		if got, want := a.domains["example.com"], []netip.Addr{addr}; !slices.Equal(got, want) {
+			t.Errorf("got %v; want %v", got, want)
+		}
+
+		// domains are explicitly downcased on set.
+		a.UpdateDomains([]string{"UP.EXAMPLE.COM"})
+		a.Wait(ctx)
+		if got, want := xmaps.Keys(a.domains), []string{"up.example.com"}; !slices.Equal(got, want) {
+			t.Errorf("got %v; want %v", got, want)
+		}
 	}
 }
 
 func TestUpdateRoutes(t *testing.T) {
-	rc := &routeCollector{}
-	a := NewAppConnector(t.Logf, rc)
-	routes := []netip.Prefix{netip.MustParsePrefix("192.0.2.0/24")}
-	a.UpdateRoutes(routes)
+	for _, shouldStore := range []bool{false, true} {
+		ctx := context.Background()
+		rc := &appctest.RouteCollector{}
+		var a *AppConnector
+		if shouldStore {
+			a = NewAppConnector(t.Logf, rc, &RouteInfo{}, fakeStoreRoutes)
+		} else {
+			a = NewAppConnector(t.Logf, rc, nil, nil)
+		}
+		a.updateDomains([]string{"*.example.com"})
 
-	if !slices.EqualFunc(routes, rc.routes, prefixEqual) {
-		t.Fatalf("got %v, want %v", rc.routes, routes)
+		// This route should be collapsed into the range
+		a.ObserveDNSResponse(dnsResponse("a.example.com.", "192.0.2.1"))
+		a.Wait(ctx)
+
+		if !slices.Equal(rc.Routes(), []netip.Prefix{netip.MustParsePrefix("192.0.2.1/32")}) {
+			t.Fatalf("got %v, want %v", rc.Routes(), []netip.Prefix{netip.MustParsePrefix("192.0.2.1/32")})
+		}
+
+		// This route should not be collapsed or removed
+		a.ObserveDNSResponse(dnsResponse("b.example.com.", "192.0.0.1"))
+		a.Wait(ctx)
+
+		routes := []netip.Prefix{netip.MustParsePrefix("192.0.2.0/24"), netip.MustParsePrefix("192.0.0.1/32")}
+		a.updateRoutes(routes)
+
+		slices.SortFunc(rc.Routes(), prefixCompare)
+		rc.SetRoutes(slices.Compact(rc.Routes()))
+		slices.SortFunc(routes, prefixCompare)
+
+		// Ensure that the non-matching /32 is preserved, even though it's in the domains table.
+		if !slices.EqualFunc(routes, rc.Routes(), prefixEqual) {
+			t.Errorf("added routes: got %v, want %v", rc.Routes(), routes)
+		}
+
+		// Ensure that the contained /32 is removed, replaced by the /24.
+		wantRemoved := []netip.Prefix{netip.MustParsePrefix("192.0.2.1/32")}
+		if !slices.EqualFunc(rc.RemovedRoutes(), wantRemoved, prefixEqual) {
+			t.Fatalf("unexpected removed routes: %v", rc.RemovedRoutes())
+		}
 	}
 }
 
 func TestUpdateRoutesUnadvertisesContainedRoutes(t *testing.T) {
-	rc := &routeCollector{}
-	a := NewAppConnector(t.Logf, rc)
-	mak.Set(&a.domains, "example.com", []netip.Addr{netip.MustParseAddr("192.0.2.1")})
-	rc.routes = []netip.Prefix{netip.MustParsePrefix("192.0.2.1/32")}
-	routes := []netip.Prefix{netip.MustParsePrefix("192.0.2.0/24")}
-	a.UpdateRoutes(routes)
+	for _, shouldStore := range []bool{false, true} {
+		rc := &appctest.RouteCollector{}
+		var a *AppConnector
+		if shouldStore {
+			a = NewAppConnector(t.Logf, rc, &RouteInfo{}, fakeStoreRoutes)
+		} else {
+			a = NewAppConnector(t.Logf, rc, nil, nil)
+		}
+		mak.Set(&a.domains, "example.com", []netip.Addr{netip.MustParseAddr("192.0.2.1")})
+		rc.SetRoutes([]netip.Prefix{netip.MustParsePrefix("192.0.2.1/32")})
+		routes := []netip.Prefix{netip.MustParsePrefix("192.0.2.0/24")}
+		a.updateRoutes(routes)
 
-	if !slices.EqualFunc(routes, rc.routes, prefixEqual) {
-		t.Fatalf("got %v, want %v", rc.routes, routes)
+		if !slices.EqualFunc(routes, rc.Routes(), prefixEqual) {
+			t.Fatalf("got %v, want %v", rc.Routes(), routes)
+		}
 	}
 }
 
 func TestDomainRoutes(t *testing.T) {
-	rc := &routeCollector{}
-	a := NewAppConnector(t.Logf, rc)
-	a.UpdateDomains([]string{"example.com"})
-	a.ObserveDNSResponse(dnsResponse("example.com.", "192.0.0.8"))
+	for _, shouldStore := range []bool{false, true} {
+		rc := &appctest.RouteCollector{}
+		var a *AppConnector
+		if shouldStore {
+			a = NewAppConnector(t.Logf, rc, &RouteInfo{}, fakeStoreRoutes)
+		} else {
+			a = NewAppConnector(t.Logf, rc, nil, nil)
+		}
+		a.updateDomains([]string{"example.com"})
+		a.ObserveDNSResponse(dnsResponse("example.com.", "192.0.0.8"))
+		a.Wait(context.Background())
 
-	want := map[string][]netip.Addr{
-		"example.com": {netip.MustParseAddr("192.0.0.8")},
-	}
+		want := map[string][]netip.Addr{
+			"example.com": {netip.MustParseAddr("192.0.0.8")},
+		}
 
-	if got := a.DomainRoutes(); !reflect.DeepEqual(got, want) {
-		t.Fatalf("DomainRoutes: got %v, want %v", got, want)
+		if got := a.DomainRoutes(); !reflect.DeepEqual(got, want) {
+			t.Fatalf("DomainRoutes: got %v, want %v", got, want)
+		}
 	}
 }
 
 func TestObserveDNSResponse(t *testing.T) {
-	rc := &routeCollector{}
-	a := NewAppConnector(t.Logf, rc)
+	for _, shouldStore := range []bool{false, true} {
+		ctx := context.Background()
+		rc := &appctest.RouteCollector{}
+		var a *AppConnector
+		if shouldStore {
+			a = NewAppConnector(t.Logf, rc, &RouteInfo{}, fakeStoreRoutes)
+		} else {
+			a = NewAppConnector(t.Logf, rc, nil, nil)
+		}
 
-	// a has no domains configured, so it should not advertise any routes
-	a.ObserveDNSResponse(dnsResponse("example.com.", "192.0.0.8"))
-	if got, want := rc.routes, ([]netip.Prefix)(nil); !slices.Equal(got, want) {
-		t.Errorf("got %v; want %v", got, want)
-	}
+		// a has no domains configured, so it should not advertise any routes
+		a.ObserveDNSResponse(dnsResponse("example.com.", "192.0.0.8"))
+		if got, want := rc.Routes(), ([]netip.Prefix)(nil); !slices.Equal(got, want) {
+			t.Errorf("got %v; want %v", got, want)
+		}
 
-	wantRoutes := []netip.Prefix{netip.MustParsePrefix("192.0.0.8/32")}
+		wantRoutes := []netip.Prefix{netip.MustParsePrefix("192.0.0.8/32")}
 
-	a.UpdateDomains([]string{"example.com"})
-	a.ObserveDNSResponse(dnsResponse("example.com.", "192.0.0.8"))
-	if got, want := rc.routes, wantRoutes; !slices.Equal(got, want) {
-		t.Errorf("got %v; want %v", got, want)
-	}
+		a.updateDomains([]string{"example.com"})
+		a.ObserveDNSResponse(dnsResponse("example.com.", "192.0.0.8"))
+		a.Wait(ctx)
+		if got, want := rc.Routes(), wantRoutes; !slices.Equal(got, want) {
+			t.Errorf("got %v; want %v", got, want)
+		}
 
-	wantRoutes = append(wantRoutes, netip.MustParsePrefix("2001:db8::1/128"))
+		// a CNAME record chain should result in a route being added if the chain
+		// matches a routed domain.
+		a.updateDomains([]string{"www.example.com", "example.com"})
+		a.ObserveDNSResponse(dnsCNAMEResponse("192.0.0.9", "www.example.com.", "chain.example.com.", "example.com."))
+		a.Wait(ctx)
+		wantRoutes = append(wantRoutes, netip.MustParsePrefix("192.0.0.9/32"))
+		if got, want := rc.Routes(), wantRoutes; !slices.Equal(got, want) {
+			t.Errorf("got %v; want %v", got, want)
+		}
 
-	a.ObserveDNSResponse(dnsResponse("example.com.", "2001:db8::1"))
-	if got, want := rc.routes, wantRoutes; !slices.Equal(got, want) {
-		t.Errorf("got %v; want %v", got, want)
-	}
+		// a CNAME record chain should result in a route being added if the chain
+		// even if only found in the middle of the chain
+		a.ObserveDNSResponse(dnsCNAMEResponse("192.0.0.10", "outside.example.org.", "www.example.com.", "example.org."))
+		a.Wait(ctx)
+		wantRoutes = append(wantRoutes, netip.MustParsePrefix("192.0.0.10/32"))
+		if got, want := rc.Routes(), wantRoutes; !slices.Equal(got, want) {
+			t.Errorf("got %v; want %v", got, want)
+		}
 
-	// don't re-advertise routes that have already been advertised
-	a.ObserveDNSResponse(dnsResponse("example.com.", "2001:db8::1"))
-	if !slices.Equal(rc.routes, wantRoutes) {
-		t.Errorf("rc.routes: got %v; want %v", rc.routes, wantRoutes)
-	}
+		wantRoutes = append(wantRoutes, netip.MustParsePrefix("2001:db8::1/128"))
 
-	// don't advertise addresses that are already in a control provided route
-	pfx := netip.MustParsePrefix("192.0.2.0/24")
-	a.UpdateRoutes([]netip.Prefix{pfx})
-	wantRoutes = append(wantRoutes, pfx)
-	a.ObserveDNSResponse(dnsResponse("example.com.", "192.0.2.1"))
-	if !slices.Equal(rc.routes, wantRoutes) {
-		t.Errorf("rc.routes: got %v; want %v", rc.routes, wantRoutes)
-	}
-	if !slices.Contains(a.domains["example.com"], netip.MustParseAddr("192.0.2.1")) {
-		t.Errorf("missing %v from %v", "192.0.2.1", a.domains["exmaple.com"])
+		a.ObserveDNSResponse(dnsResponse("example.com.", "2001:db8::1"))
+		a.Wait(ctx)
+		if got, want := rc.Routes(), wantRoutes; !slices.Equal(got, want) {
+			t.Errorf("got %v; want %v", got, want)
+		}
+
+		// don't re-advertise routes that have already been advertised
+		a.ObserveDNSResponse(dnsResponse("example.com.", "2001:db8::1"))
+		a.Wait(ctx)
+		if !slices.Equal(rc.Routes(), wantRoutes) {
+			t.Errorf("rc.Routes(): got %v; want %v", rc.Routes(), wantRoutes)
+		}
+
+		// don't advertise addresses that are already in a control provided route
+		pfx := netip.MustParsePrefix("192.0.2.0/24")
+		a.updateRoutes([]netip.Prefix{pfx})
+		wantRoutes = append(wantRoutes, pfx)
+		a.ObserveDNSResponse(dnsResponse("example.com.", "192.0.2.1"))
+		a.Wait(ctx)
+		if !slices.Equal(rc.Routes(), wantRoutes) {
+			t.Errorf("rc.Routes(): got %v; want %v", rc.Routes(), wantRoutes)
+		}
+		if !slices.Contains(a.domains["example.com"], netip.MustParseAddr("192.0.2.1")) {
+			t.Errorf("missing %v from %v", "192.0.2.1", a.domains["exmaple.com"])
+		}
 	}
 }
 
 func TestWildcardDomains(t *testing.T) {
-	rc := &routeCollector{}
-	a := NewAppConnector(t.Logf, rc)
+	for _, shouldStore := range []bool{false, true} {
+		ctx := context.Background()
+		rc := &appctest.RouteCollector{}
+		var a *AppConnector
+		if shouldStore {
+			a = NewAppConnector(t.Logf, rc, &RouteInfo{}, fakeStoreRoutes)
+		} else {
+			a = NewAppConnector(t.Logf, rc, nil, nil)
+		}
 
-	a.UpdateDomains([]string{"*.example.com"})
-	a.ObserveDNSResponse(dnsResponse("foo.example.com.", "192.0.0.8"))
-	if got, want := rc.routes, []netip.Prefix{netip.MustParsePrefix("192.0.0.8/32")}; !slices.Equal(got, want) {
-		t.Errorf("routes: got %v; want %v", got, want)
-	}
-	if got, want := a.wildcards, []string{"example.com"}; !slices.Equal(got, want) {
-		t.Errorf("wildcards: got %v; want %v", got, want)
-	}
+		a.updateDomains([]string{"*.example.com"})
+		a.ObserveDNSResponse(dnsResponse("foo.example.com.", "192.0.0.8"))
+		a.Wait(ctx)
+		if got, want := rc.Routes(), []netip.Prefix{netip.MustParsePrefix("192.0.0.8/32")}; !slices.Equal(got, want) {
+			t.Errorf("routes: got %v; want %v", got, want)
+		}
+		if got, want := a.wildcards, []string{"example.com"}; !slices.Equal(got, want) {
+			t.Errorf("wildcards: got %v; want %v", got, want)
+		}
 
-	a.UpdateDomains([]string{"*.example.com", "example.com"})
-	if _, ok := a.domains["foo.example.com"]; !ok {
-		t.Errorf("expected foo.example.com to be preserved in domains due to wildcard")
-	}
-	if got, want := a.wildcards, []string{"example.com"}; !slices.Equal(got, want) {
-		t.Errorf("wildcards: got %v; want %v", got, want)
-	}
+		a.updateDomains([]string{"*.example.com", "example.com"})
+		if _, ok := a.domains["foo.example.com"]; !ok {
+			t.Errorf("expected foo.example.com to be preserved in domains due to wildcard")
+		}
+		if got, want := a.wildcards, []string{"example.com"}; !slices.Equal(got, want) {
+			t.Errorf("wildcards: got %v; want %v", got, want)
+		}
 
-	// There was an early regression where the wildcard domain was added repeatedly, this guards against that.
-	a.UpdateDomains([]string{"*.example.com", "example.com"})
-	if len(a.wildcards) != 1 {
-		t.Errorf("expected only one wildcard domain, got %v", a.wildcards)
+		// There was an early regression where the wildcard domain was added repeatedly, this guards against that.
+		a.updateDomains([]string{"*.example.com", "example.com"})
+		if len(a.wildcards) != 1 {
+			t.Errorf("expected only one wildcard domain, got %v", a.wildcards)
+		}
 	}
 }
 
@@ -185,30 +289,234 @@ func dnsResponse(domain, address string) []byte {
 	return must.Get(b.Finish())
 }
 
-// routeCollector is a test helper that collects the list of routes advertised
-type routeCollector struct {
-	routes []netip.Prefix
-}
+func dnsCNAMEResponse(address string, domains ...string) []byte {
+	addr := netip.MustParseAddr(address)
+	b := dnsmessage.NewBuilder(nil, dnsmessage.Header{})
+	b.EnableCompression()
+	b.StartAnswers()
 
-// routeCollector implements RouteAdvertiser
-var _ RouteAdvertiser = (*routeCollector)(nil)
-
-func (rc *routeCollector) AdvertiseRoute(pfx netip.Prefix) error {
-	rc.routes = append(rc.routes, pfx)
-	return nil
-}
-
-func (rc *routeCollector) UnadvertiseRoute(pfx netip.Prefix) error {
-	routes := rc.routes
-	rc.routes = rc.routes[:0]
-	for _, r := range routes {
-		if r != pfx {
-			rc.routes = append(rc.routes, r)
+	if len(domains) >= 2 {
+		for i, domain := range domains[:len(domains)-1] {
+			b.CNAMEResource(
+				dnsmessage.ResourceHeader{
+					Name:  dnsmessage.MustNewName(domain),
+					Type:  dnsmessage.TypeCNAME,
+					Class: dnsmessage.ClassINET,
+					TTL:   0,
+				},
+				dnsmessage.CNAMEResource{
+					CNAME: dnsmessage.MustNewName(domains[i+1]),
+				},
+			)
 		}
 	}
-	return nil
+
+	domain := domains[len(domains)-1]
+
+	switch addr.BitLen() {
+	case 32:
+		b.AResource(
+			dnsmessage.ResourceHeader{
+				Name:  dnsmessage.MustNewName(domain),
+				Type:  dnsmessage.TypeA,
+				Class: dnsmessage.ClassINET,
+				TTL:   0,
+			},
+			dnsmessage.AResource{
+				A: addr.As4(),
+			},
+		)
+	case 128:
+		b.AAAAResource(
+			dnsmessage.ResourceHeader{
+				Name:  dnsmessage.MustNewName(domain),
+				Type:  dnsmessage.TypeAAAA,
+				Class: dnsmessage.ClassINET,
+				TTL:   0,
+			},
+			dnsmessage.AAAAResource{
+				AAAA: addr.As16(),
+			},
+		)
+	default:
+		panic("invalid address length")
+	}
+	return must.Get(b.Finish())
 }
 
 func prefixEqual(a, b netip.Prefix) bool {
-	return a.Addr().Compare(b.Addr()) == 0 && a.Bits() == b.Bits()
+	return a == b
+}
+
+func prefixCompare(a, b netip.Prefix) int {
+	if a.Addr().Compare(b.Addr()) == 0 {
+		return a.Bits() - b.Bits()
+	}
+	return a.Addr().Compare(b.Addr())
+}
+
+func prefixes(in ...string) []netip.Prefix {
+	toRet := make([]netip.Prefix, len(in))
+	for i, s := range in {
+		toRet[i] = netip.MustParsePrefix(s)
+	}
+	return toRet
+}
+
+func TestUpdateRouteRouteRemoval(t *testing.T) {
+	for _, shouldStore := range []bool{false, true} {
+		ctx := context.Background()
+		rc := &appctest.RouteCollector{}
+
+		assertRoutes := func(prefix string, routes, removedRoutes []netip.Prefix) {
+			if !slices.Equal(routes, rc.Routes()) {
+				t.Fatalf("%s: (shouldStore=%t) routes want %v, got %v", prefix, shouldStore, routes, rc.Routes())
+			}
+			if !slices.Equal(removedRoutes, rc.RemovedRoutes()) {
+				t.Fatalf("%s: (shouldStore=%t) removedRoutes want %v, got %v", prefix, shouldStore, removedRoutes, rc.RemovedRoutes())
+			}
+		}
+
+		var a *AppConnector
+		if shouldStore {
+			a = NewAppConnector(t.Logf, rc, &RouteInfo{}, fakeStoreRoutes)
+		} else {
+			a = NewAppConnector(t.Logf, rc, nil, nil)
+		}
+		// nothing has yet been advertised
+		assertRoutes("appc init", []netip.Prefix{}, []netip.Prefix{})
+
+		a.UpdateDomainsAndRoutes([]string{}, prefixes("1.2.3.1/32", "1.2.3.2/32"))
+		a.Wait(ctx)
+		// the routes passed to UpdateDomainsAndRoutes have been advertised
+		assertRoutes("simple update", prefixes("1.2.3.1/32", "1.2.3.2/32"), []netip.Prefix{})
+
+		// one route the same, one different
+		a.UpdateDomainsAndRoutes([]string{}, prefixes("1.2.3.1/32", "1.2.3.3/32"))
+		a.Wait(ctx)
+		// old behavior: routes are not removed, resulting routes are both old and new
+		// (we have dupe 1.2.3.1 routes because the test RouteAdvertiser doesn't have the deduplication
+		// the real one does)
+		wantRoutes := prefixes("1.2.3.1/32", "1.2.3.2/32", "1.2.3.1/32", "1.2.3.3/32")
+		wantRemovedRoutes := []netip.Prefix{}
+		if shouldStore {
+			// new behavior: routes are removed, resulting routes are new only
+			wantRoutes = prefixes("1.2.3.1/32", "1.2.3.1/32", "1.2.3.3/32")
+			wantRemovedRoutes = prefixes("1.2.3.2/32")
+		}
+		assertRoutes("removal", wantRoutes, wantRemovedRoutes)
+	}
+}
+
+func TestUpdateDomainRouteRemoval(t *testing.T) {
+	for _, shouldStore := range []bool{false, true} {
+		ctx := context.Background()
+		rc := &appctest.RouteCollector{}
+
+		assertRoutes := func(prefix string, routes, removedRoutes []netip.Prefix) {
+			if !slices.Equal(routes, rc.Routes()) {
+				t.Fatalf("%s: (shouldStore=%t) routes want %v, got %v", prefix, shouldStore, routes, rc.Routes())
+			}
+			if !slices.Equal(removedRoutes, rc.RemovedRoutes()) {
+				t.Fatalf("%s: (shouldStore=%t) removedRoutes want %v, got %v", prefix, shouldStore, removedRoutes, rc.RemovedRoutes())
+			}
+		}
+
+		var a *AppConnector
+		if shouldStore {
+			a = NewAppConnector(t.Logf, rc, &RouteInfo{}, fakeStoreRoutes)
+		} else {
+			a = NewAppConnector(t.Logf, rc, nil, nil)
+		}
+		assertRoutes("appc init", []netip.Prefix{}, []netip.Prefix{})
+
+		a.UpdateDomainsAndRoutes([]string{"a.example.com", "b.example.com"}, []netip.Prefix{})
+		a.Wait(ctx)
+		// adding domains doesn't immediately cause any routes to be advertised
+		assertRoutes("update domains", []netip.Prefix{}, []netip.Prefix{})
+
+		a.ObserveDNSResponse(dnsResponse("a.example.com.", "1.2.3.1"))
+		a.ObserveDNSResponse(dnsResponse("a.example.com.", "1.2.3.2"))
+		a.ObserveDNSResponse(dnsResponse("b.example.com.", "1.2.3.3"))
+		a.ObserveDNSResponse(dnsResponse("b.example.com.", "1.2.3.4"))
+		a.Wait(ctx)
+		// observing dns responses causes routes to be advertised
+		assertRoutes("observed dns", prefixes("1.2.3.1/32", "1.2.3.2/32", "1.2.3.3/32", "1.2.3.4/32"), []netip.Prefix{})
+
+		a.UpdateDomainsAndRoutes([]string{"a.example.com"}, []netip.Prefix{})
+		a.Wait(ctx)
+		// old behavior, routes are not removed
+		wantRoutes := prefixes("1.2.3.1/32", "1.2.3.2/32", "1.2.3.3/32", "1.2.3.4/32")
+		wantRemovedRoutes := []netip.Prefix{}
+		if shouldStore {
+			// new behavior, routes are removed for b.example.com
+			wantRoutes = prefixes("1.2.3.1/32", "1.2.3.2/32")
+			wantRemovedRoutes = prefixes("1.2.3.3/32", "1.2.3.4/32")
+		}
+		assertRoutes("removal", wantRoutes, wantRemovedRoutes)
+	}
+}
+
+func TestUpdateWildcardRouteRemoval(t *testing.T) {
+	for _, shouldStore := range []bool{false, true} {
+		ctx := context.Background()
+		rc := &appctest.RouteCollector{}
+
+		assertRoutes := func(prefix string, routes, removedRoutes []netip.Prefix) {
+			if !slices.Equal(routes, rc.Routes()) {
+				t.Fatalf("%s: (shouldStore=%t) routes want %v, got %v", prefix, shouldStore, routes, rc.Routes())
+			}
+			if !slices.Equal(removedRoutes, rc.RemovedRoutes()) {
+				t.Fatalf("%s: (shouldStore=%t) removedRoutes want %v, got %v", prefix, shouldStore, removedRoutes, rc.RemovedRoutes())
+			}
+		}
+
+		var a *AppConnector
+		if shouldStore {
+			a = NewAppConnector(t.Logf, rc, &RouteInfo{}, fakeStoreRoutes)
+		} else {
+			a = NewAppConnector(t.Logf, rc, nil, nil)
+		}
+		assertRoutes("appc init", []netip.Prefix{}, []netip.Prefix{})
+
+		a.UpdateDomainsAndRoutes([]string{"a.example.com", "*.b.example.com"}, []netip.Prefix{})
+		a.Wait(ctx)
+		// adding domains doesn't immediately cause any routes to be advertised
+		assertRoutes("update domains", []netip.Prefix{}, []netip.Prefix{})
+
+		a.ObserveDNSResponse(dnsResponse("a.example.com.", "1.2.3.1"))
+		a.ObserveDNSResponse(dnsResponse("a.example.com.", "1.2.3.2"))
+		a.ObserveDNSResponse(dnsResponse("1.b.example.com.", "1.2.3.3"))
+		a.ObserveDNSResponse(dnsResponse("2.b.example.com.", "1.2.3.4"))
+		a.Wait(ctx)
+		// observing dns responses causes routes to be advertised
+		assertRoutes("observed dns", prefixes("1.2.3.1/32", "1.2.3.2/32", "1.2.3.3/32", "1.2.3.4/32"), []netip.Prefix{})
+
+		a.UpdateDomainsAndRoutes([]string{"a.example.com"}, []netip.Prefix{})
+		a.Wait(ctx)
+		// old behavior, routes are not removed
+		wantRoutes := prefixes("1.2.3.1/32", "1.2.3.2/32", "1.2.3.3/32", "1.2.3.4/32")
+		wantRemovedRoutes := []netip.Prefix{}
+		if shouldStore {
+			// new behavior, routes are removed for *.b.example.com
+			wantRoutes = prefixes("1.2.3.1/32", "1.2.3.2/32")
+			wantRemovedRoutes = prefixes("1.2.3.3/32", "1.2.3.4/32")
+		}
+		assertRoutes("removal", wantRoutes, wantRemovedRoutes)
+	}
+}
+
+func TestRoutesWithout(t *testing.T) {
+	assert := func(msg string, got, want []netip.Prefix) {
+		if !slices.Equal(want, got) {
+			t.Errorf("%s: want %v, got %v", msg, want, got)
+		}
+	}
+
+	assert("empty routes", routesWithout([]netip.Prefix{}, []netip.Prefix{}), []netip.Prefix{})
+	assert("a empty", routesWithout([]netip.Prefix{}, prefixes("1.1.1.1/32", "1.1.1.2/32")), []netip.Prefix{})
+	assert("b empty", routesWithout(prefixes("1.1.1.1/32", "1.1.1.2/32"), []netip.Prefix{}), prefixes("1.1.1.1/32", "1.1.1.2/32"))
+	assert("no overlap", routesWithout(prefixes("1.1.1.1/32", "1.1.1.2/32"), prefixes("1.1.1.3/32", "1.1.1.4/32")), prefixes("1.1.1.1/32", "1.1.1.2/32"))
+	assert("a has fewer", routesWithout(prefixes("1.1.1.1/32", "1.1.1.2/32"), prefixes("1.1.1.1/32", "1.1.1.2/32", "1.1.1.3/32", "1.1.1.4/32")), []netip.Prefix{})
+	assert("a has more", routesWithout(prefixes("1.1.1.1/32", "1.1.1.2/32", "1.1.1.3/32", "1.1.1.4/32"), prefixes("1.1.1.1/32", "1.1.1.3/32")), prefixes("1.1.1.2/32", "1.1.1.4/32"))
 }

appc/appctest/appctest.go

@@ -0,0 +1,49 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package appctest
+
+import (
+	"net/netip"
+	"slices"
+)
+
+// RouteCollector is a test helper that collects the list of routes advertised
+type RouteCollector struct {
+	routes        []netip.Prefix
+	removedRoutes []netip.Prefix
+}
+
+func (rc *RouteCollector) AdvertiseRoute(pfx ...netip.Prefix) error {
+	rc.routes = append(rc.routes, pfx...)
+	return nil
+}
+
+func (rc *RouteCollector) UnadvertiseRoute(toRemove ...netip.Prefix) error {
+	routes := rc.routes
+	rc.routes = rc.routes[:0]
+	for _, r := range routes {
+		if !slices.Contains(toRemove, r) {
+			rc.routes = append(rc.routes, r)
+		} else {
+			rc.removedRoutes = append(rc.removedRoutes, r)
+		}
+	}
+	return nil
+}
+
+// RemovedRoutes returns the list of routes that were removed.
+func (rc *RouteCollector) RemovedRoutes() []netip.Prefix {
+	return rc.removedRoutes
+}
+
+// Routes returns the ordered list of routes that were added, including
+// possible duplicates.
+func (rc *RouteCollector) Routes() []netip.Prefix {
+	return rc.routes
+}
+
+func (rc *RouteCollector) SetRoutes(routes []netip.Prefix) error {
+	rc.routes = routes
+	return nil
+}

build_dist.sh

@@ -37,7 +37,7 @@ while [ "$#" -gt 1 ]; do
 	--extra-small)
 		shift
 		ldflags="$ldflags -w -s"
-		tags="${tags:+$tags,}ts_omit_aws,ts_omit_bird,ts_omit_tap,ts_omit_kube"
+		tags="${tags:+$tags,}ts_omit_aws,ts_omit_bird,ts_omit_tap,ts_omit_kube,ts_omit_completion"
 		;;
 	--box)
 		shift

build_docker.sh

@@ -20,9 +20,9 @@
 set -eu
 
 # Use the "go" binary from the "tool" directory (which is github.com/tailscale/go)
-export PATH=$PWD/tool:$PATH
+export PATH="$PWD"/tool:"$PATH"
 
-eval $(./build_dist.sh shellvars)
+eval "$(./build_dist.sh shellvars)"
 
 DEFAULT_TARGET="client"
 DEFAULT_TAGS="v${VERSION_SHORT},v${VERSION_MINOR}"
@@ -49,6 +49,7 @@ case "$TARGET" in
         -X tailscale.com/version.gitCommitStamp=${VERSION_GIT_HASH}" \
       --base="${BASE}" \
       --tags="${TAGS}" \
+      --gotags="ts_kube" \
       --repos="${REPOS}" \
       --push="${PUSH}" \
       --target="${PLATFORM}" \
@@ -70,8 +71,24 @@ case "$TARGET" in
       --target="${PLATFORM}" \
       /usr/local/bin/operator
     ;;
+  k8s-nameserver)
+    DEFAULT_REPOS="tailscale/k8s-nameserver"
+    REPOS="${REPOS:-${DEFAULT_REPOS}}"
+    go run github.com/tailscale/mkctr \
+      --gopaths="tailscale.com/cmd/k8s-nameserver:/usr/local/bin/k8s-nameserver" \
+      --ldflags=" \
+        -X tailscale.com/version.longStamp=${VERSION_LONG} \
+        -X tailscale.com/version.shortStamp=${VERSION_SHORT} \
+        -X tailscale.com/version.gitCommitStamp=${VERSION_GIT_HASH}" \
+      --base="${BASE}" \
+      --tags="${TAGS}" \
+      --repos="${REPOS}" \
+      --push="${PUSH}" \
+      --target="${PLATFORM}" \
+      /usr/local/bin/k8s-nameserver
+    ;;
   *)
     echo "unknown target: $TARGET"
     exit 1
     ;;
-esac
+esac

client/tailscale/acl.go

@@ -270,6 +270,14 @@ type UserRuleMatch struct {
 	Users      []string `json:"users"`
 	Ports      []string `json:"ports"`
 	LineNumber int      `json:"lineNumber"`
+
+	// Postures is a list of posture policies that are
+	// associated with this match. The rules can be looked
+	// up in the ACLPreviewResponse parent struct.
+	// The source of the list is from srcPosture on
+	// an ACL or Grant rule:
+	// https://tailscale.com/kb/1288/device-posture#posture-conditions
+	Postures []string `json:"postures"`
 }
 
 // ACLPreviewResponse is the response type of previewACLPostRequest
@@ -277,6 +285,12 @@ type ACLPreviewResponse struct {
 	Matches    []UserRuleMatch `json:"matches"`    // ACL rules that match the specified user or ipport.
 	Type       string          `json:"type"`       // The request type: currently only "user" or "ipport".
 	PreviewFor string          `json:"previewFor"` // A specific user or ipport.
+
+	// Postures is a map of postures and associated rules that apply
+	// to this preview.
+	// For more details about the posture mapping, see:
+	// https://tailscale.com/kb/1288/device-posture#postures
+	Postures map[string][]string `json:"postures,omitempty"`
 }
 
 // ACLPreview is the response type of PreviewACLForUser, PreviewACLForIPPort, PreviewACLHuJSONForUser, and PreviewACLHuJSONForIPPort
@@ -284,6 +298,12 @@ type ACLPreview struct {
 	Matches []UserRuleMatch `json:"matches"`
 	User    string          `json:"user,omitempty"`   // Filled if response of PreviewACLForUser or PreviewACLHuJSONForUser
 	IPPort  string          `json:"ipport,omitempty"` // Filled if response of PreviewACLForIPPort or PreviewACLHuJSONForIPPort
+
+	// Postures is a map of postures and associated rules that apply
+	// to this preview.
+	// For more details about the posture mapping, see:
+	// https://tailscale.com/kb/1288/device-posture#postures
+	Postures map[string][]string `json:"postures,omitempty"`
 }
 
 func (c *Client) previewACLPostRequest(ctx context.Context, body []byte, previewType string, previewFor string) (res *ACLPreviewResponse, err error) {
@@ -341,8 +361,9 @@ func (c *Client) PreviewACLForUser(ctx context.Context, acl ACL, user string) (r
 	}
 
 	return &ACLPreview{
-		Matches: b.Matches,
-		User:    b.PreviewFor,
+		Matches:  b.Matches,
+		User:     b.PreviewFor,
+		Postures: b.Postures,
 	}, nil
 }
 
@@ -369,8 +390,9 @@ func (c *Client) PreviewACLForIPPort(ctx context.Context, acl ACL, ipport netip.
 	}
 
 	return &ACLPreview{
-		Matches: b.Matches,
-		IPPort:  b.PreviewFor,
+		Matches:  b.Matches,
+		IPPort:   b.PreviewFor,
+		Postures: b.Postures,
 	}, nil
 }
 
@@ -394,8 +416,9 @@ func (c *Client) PreviewACLHuJSONForUser(ctx context.Context, acl ACLHuJSON, use
 	}
 
 	return &ACLPreview{
-		Matches: b.Matches,
-		User:    b.PreviewFor,
+		Matches:  b.Matches,
+		User:     b.PreviewFor,
+		Postures: b.Postures,
 	}, nil
 }
 
@@ -419,8 +442,9 @@ func (c *Client) PreviewACLHuJSONForIPPort(ctx context.Context, acl ACLHuJSON, i
 	}
 
 	return &ACLPreview{
-		Matches: b.Matches,
-		IPPort:  b.PreviewFor,
+		Matches:  b.Matches,
+		IPPort:   b.PreviewFor,
+		Postures: b.Postures,
 	}, nil
 }
 

client/tailscale/apitype/apitype.go

@@ -49,3 +49,11 @@ type ReloadConfigResponse struct {
 	Reloaded bool   // whether the config was reloaded
 	Err      string // any error message
 }
+
+// ExitNodeSuggestionResponse is the response to a LocalAPI suggest-exit-node GET request.
+// It returns the StableNodeID, name, and location of a suggested exit node for the client making the request.
+type ExitNodeSuggestionResponse struct {
+	ID       tailcfg.StableNodeID
+	Name     string
+	Location tailcfg.LocationView `json:",omitempty"`
+}

client/tailscale/localclient.go

@@ -7,6 +7,7 @@ package tailscale
 
 import (
 	"bytes"
+	"cmp"
 	"context"
 	"crypto/tls"
 	"encoding/json"
@@ -27,6 +28,7 @@ import (
 
 	"go4.org/mem"
 	"tailscale.com/client/tailscale/apitype"
+	"tailscale.com/drive"
 	"tailscale.com/envknob"
 	"tailscale.com/ipn"
 	"tailscale.com/ipn/ipnstate"
@@ -37,7 +39,6 @@ import (
 	"tailscale.com/tka"
 	"tailscale.com/types/key"
 	"tailscale.com/types/tkatype"
-	"tailscale.com/util/cmpx"
 )
 
 // defaultLocalClient is the default LocalClient when using the legacy
@@ -479,7 +480,7 @@ func (lc *LocalClient) DebugPortmap(ctx context.Context, opts *DebugPortmapOpts)
 		opts = &DebugPortmapOpts{}
 	}
 
-	vals.Set("duration", cmpx.Or(opts.Duration, 5*time.Second).String())
+	vals.Set("duration", cmp.Or(opts.Duration, 5*time.Second).String())
 	vals.Set("type", opts.Type)
 	vals.Set("log_http", strconv.FormatBool(opts.LogHTTP))
 
@@ -1417,6 +1418,66 @@ func (lc *LocalClient) CheckUpdate(ctx context.Context) (*tailcfg.ClientVersion,
 	return &cv, nil
 }
 
+// SetUseExitNode toggles the use of an exit node on or off.
+// To turn it on, there must have been a previously used exit node.
+// The most previously used one is reused.
+// This is a convenience method for GUIs. To select an actual one, update the prefs.
+func (lc *LocalClient) SetUseExitNode(ctx context.Context, on bool) error {
+	_, err := lc.send(ctx, "POST", "/localapi/v0/set-use-exit-node-enabled?enabled="+strconv.FormatBool(on), http.StatusOK, nil)
+	return err
+}
+
+// DriveSetServerAddr instructs Taildrive to use the server at addr to access
+// the filesystem. This is used on platforms like Windows and MacOS to let
+// Taildrive know to use the file server running in the GUI app.
+func (lc *LocalClient) DriveSetServerAddr(ctx context.Context, addr string) error {
+	_, err := lc.send(ctx, "PUT", "/localapi/v0/drive/fileserver-address", http.StatusCreated, strings.NewReader(addr))
+	return err
+}
+
+// DriveShareSet adds or updates the given share in the list of shares that
+// Taildrive will serve to remote nodes. If a share with the same name already
+// exists, the existing share is replaced/updated.
+func (lc *LocalClient) DriveShareSet(ctx context.Context, share *drive.Share) error {
+	_, err := lc.send(ctx, "PUT", "/localapi/v0/drive/shares", http.StatusCreated, jsonBody(share))
+	return err
+}
+
+// DriveShareRemove removes the share with the given name from the list of
+// shares that Taildrive will serve to remote nodes.
+func (lc *LocalClient) DriveShareRemove(ctx context.Context, name string) error {
+	_, err := lc.send(
+		ctx,
+		"DELETE",
+		"/localapi/v0/drive/shares",
+		http.StatusNoContent,
+		strings.NewReader(name))
+	return err
+}
+
+// DriveShareRename renames the share from old to new name.
+func (lc *LocalClient) DriveShareRename(ctx context.Context, oldName, newName string) error {
+	_, err := lc.send(
+		ctx,
+		"POST",
+		"/localapi/v0/drive/shares",
+		http.StatusNoContent,
+		jsonBody([2]string{oldName, newName}))
+	return err
+}
+
+// DriveShareList returns the list of shares that drive is currently serving
+// to remote nodes.
+func (lc *LocalClient) DriveShareList(ctx context.Context) ([]*drive.Share, error) {
+	result, err := lc.get200(ctx, "/localapi/v0/drive/shares")
+	if err != nil {
+		return nil, err
+	}
+	var shares []*drive.Share
+	err = json.Unmarshal(result, &shares)
+	return shares, err
+}
+
 // IPNBusWatcher is an active subscription (watch) of the local tailscaled IPN bus.
 // It's returned by LocalClient.WatchIPNBus.
 //
@@ -1453,3 +1514,12 @@ func (w *IPNBusWatcher) Next() (ipn.Notify, error) {
 	}
 	return n, nil
 }
+
+// SuggestExitNode requests an exit node suggestion and returns the exit node's details.
+func (lc *LocalClient) SuggestExitNode(ctx context.Context) (apitype.ExitNodeSuggestionResponse, error) {
+	body, err := lc.get200(ctx, "/localapi/v0/suggest-exit-node")
+	if err != nil {
+		return apitype.ExitNodeSuggestionResponse{}, err
+	}
+	return decodeJSON[apitype.ExitNodeSuggestionResponse](body)
+}

client/tailscale/localclient_test.go

@@ -5,7 +5,11 @@
 
 package tailscale
 
-import "testing"
+import (
+	"testing"
+
+	"tailscale.com/tstest/deptest"
+)
 
 func TestGetServeConfigFromJSON(t *testing.T) {
 	sc, err := getServeConfigFromJSON([]byte("null"))
@@ -25,3 +29,14 @@ func TestGetServeConfigFromJSON(t *testing.T) {
 		t.Errorf("want non-nil TCP for object")
 	}
 }
+
+func TestDeps(t *testing.T) {
+	deptest.DepChecker{
+		BadDeps: map[string]string{
+			// Make sure we don't again accidentally bring in a dependency on
+			// drive or its transitive dependencies
+			"tailscale.com/drive/driveimpl":  "https://github.com/tailscale/tailscale/pull/10631",
+			"github.com/studio-b12/gowebdav": "https://github.com/tailscale/tailscale/pull/10631",
+		},
+	}.Check(t)
+}

client/web/auth.go

@@ -11,6 +11,7 @@ import (
 	"fmt"
 	"net/http"
 	"net/url"
+	"slices"
 	"strings"
 	"time"
 
@@ -222,7 +223,7 @@ func (s *Server) awaitUserAuth(ctx context.Context, session *browserSession) err
 
 func (s *Server) newSessionID() (string, error) {
 	raw := make([]byte, 16)
-	for i := 0; i < 5; i++ {
+	for range 5 {
 		if _, err := rand.Read(raw); err != nil {
 			return "", err
 		}
@@ -234,7 +235,12 @@ func (s *Server) newSessionID() (string, error) {
 	return "", errors.New("too many collisions generating new session; please refresh page")
 }
 
-type peerCapabilities map[capFeature]bool // value is true if the peer can edit the given feature
+// peerCapabilities holds information about what a source
+// peer is allowed to edit via the web UI.
+//
+// map value is true if the peer can edit the given feature.
+// Only capFeatures included in validCaps will be included.
+type peerCapabilities map[capFeature]bool
 
 // canEdit is true if the peerCapabilities grant edit access
 // to the given feature.
@@ -248,39 +254,85 @@ func (p peerCapabilities) canEdit(feature capFeature) bool {
 	return p[feature]
 }
 
+// isEmpty is true if p is either nil or has no capabilities
+// with value true.
+func (p peerCapabilities) isEmpty() bool {
+	if p == nil {
+		return true
+	}
+	for _, v := range p {
+		if v == true {
+			return false
+		}
+	}
+	return true
+}
+
 type capFeature string
 
 const (
 	// The following values should not be edited.
 	// New caps can be added, but existing ones should not be changed,
 	// as these exact values are used by users in tailnet policy files.
+	//
+	// IMPORTANT: When adding a new cap, also update validCaps slice below.
 
-	capFeatureAll      capFeature = "*"        // grants peer management of all features
-	capFeatureFunnel   capFeature = "funnel"   // grants peer serve/funnel management
-	capFeatureSSH      capFeature = "ssh"      // grants peer SSH server management
-	capFeatureSubnet   capFeature = "subnet"   // grants peer subnet routes management
-	capFeatureExitNode capFeature = "exitnode" // grants peer ability to advertise-as and use exit nodes
-	capFeatureAccount  capFeature = "account"  // grants peer ability to turn on auto updates and log out of node
+	capFeatureAll       capFeature = "*"         // grants peer management of all features
+	capFeatureSSH       capFeature = "ssh"       // grants peer SSH server management
+	capFeatureSubnets   capFeature = "subnets"   // grants peer subnet routes management
+	capFeatureExitNodes capFeature = "exitnodes" // grants peer ability to advertise-as and use exit nodes
+	capFeatureAccount   capFeature = "account"   // grants peer ability to turn on auto updates and log out of node
 )
 
+// validCaps contains the list of valid capabilities used in the web client.
+// Any capabilities included in a peer's grants that do not fall into this
+// list will be ignored.
+var validCaps []capFeature = []capFeature{
+	capFeatureAll,
+	capFeatureSSH,
+	capFeatureSubnets,
+	capFeatureExitNodes,
+	capFeatureAccount,
+}
+
 type capRule struct {
 	CanEdit []string `json:"canEdit,omitempty"` // list of features peer is allowed to edit
 }
 
 // toPeerCapabilities parses out the web ui capabilities from the
 // given whois response.
-func toPeerCapabilities(whois *apitype.WhoIsResponse) (peerCapabilities, error) {
-	caps := peerCapabilities{}
-	if whois == nil {
-		return caps, nil
+func toPeerCapabilities(status *ipnstate.Status, whois *apitype.WhoIsResponse) (peerCapabilities, error) {
+	if whois == nil || status == nil {
+		return peerCapabilities{}, nil
 	}
+	if whois.Node.IsTagged() {
+		// We don't allow management *from* tagged nodes, so ignore caps.
+		// The web client auth flow relies on having a true user identity
+		// that can be verified through login.
+		return peerCapabilities{}, nil
+	}
+
+	if !status.Self.IsTagged() {
+		// User owned nodes are only ever manageable by the owner.
+		if status.Self.UserID != whois.UserProfile.ID {
+			return peerCapabilities{}, nil
+		} else {
+			return peerCapabilities{capFeatureAll: true}, nil // owner can edit all features
+		}
+	}
+
+	// For tagged nodes, we actually look at the granted capabilities.
+	caps := peerCapabilities{}
 	rules, err := tailcfg.UnmarshalCapJSON[capRule](whois.CapMap, tailcfg.PeerCapabilityWebUI)
 	if err != nil {
 		return nil, fmt.Errorf("failed to unmarshal capability: %v", err)
 	}
 	for _, c := range rules {
 		for _, f := range c.CanEdit {
-			caps[capFeature(strings.ToLower(f))] = true
+			cap := capFeature(strings.ToLower(f))
+			if slices.Contains(validCaps, cap) {
+				caps[cap] = true
+			}
 		}
 	}
 	return caps, nil

client/web/package.json

@@ -6,6 +6,7 @@
     "node": "18.16.1",
     "yarn": "1.22.19"
   },
+  "type": "module",
   "private": true,
   "dependencies": {
     "@radix-ui/react-collapsible": "^1.0.3",
@@ -19,23 +20,28 @@
     "zustand": "^4.4.7"
   },
   "devDependencies": {
+    "@types/node": "^18.16.1",
     "@types/react": "^18.0.20",
     "@types/react-dom": "^18.0.6",
-    "@vitejs/plugin-react-swc": "^3.3.2",
+    "@vitejs/plugin-react-swc": "^3.6.0",
     "autoprefixer": "^10.4.15",
     "eslint": "^8.23.1",
     "eslint-config-react-app": "^7.0.1",
+    "eslint-plugin-curly-quotes": "^1.0.4",
     "jsdom": "^23.0.1",
     "postcss": "^8.4.31",
     "prettier": "^2.5.1",
     "prettier-plugin-organize-imports": "^3.2.2",
     "tailwindcss": "^3.3.3",
-    "typescript": "^4.7.4",
-    "vite": "^4.3.9",
-    "vite-plugin-rewrite-all": "^1.0.1",
-    "vite-plugin-svgr": "^3.2.0",
+    "typescript": "^5.3.3",
+    "vite": "^5.1.7",
+    "vite-plugin-svgr": "^4.2.0",
     "vite-tsconfig-paths": "^3.5.0",
-    "vitest": "^0.32.0"
+    "vitest": "^1.3.1"
+  },
+  "resolutions": {
+    "@typescript-eslint/eslint-plugin": "^6.2.1",
+    "@typescript-eslint/parser": "^6.2.1"
   },
   "scripts": {
     "build": "vite build",
@@ -50,9 +56,11 @@
       "react-app"
     ],
     "plugins": [
+      "curly-quotes",
       "react-hooks"
     ],
     "rules": {
+      "curly-quotes/no-straight-quotes": "warn",
       "react-hooks/rules-of-hooks": "error",
       "react-hooks/exhaustive-deps": "error"
     },

client/web/src/components/address-copy-card.tsx

@@ -4,8 +4,8 @@
 import * as Primitive from "@radix-ui/react-popover"
 import cx from "classnames"
 import React, { useCallback } from "react"
-import { ReactComponent as ChevronDown } from "src/assets/icons/chevron-down.svg"
-import { ReactComponent as Copy } from "src/assets/icons/copy.svg"
+import ChevronDown from "src/assets/icons/chevron-down.svg?react"
+import Copy from "src/assets/icons/copy.svg?react"
 import NiceIP from "src/components/nice-ip"
 import useToaster from "src/hooks/toaster"
 import Button from "src/ui/button"

client/web/src/components/app.tsx

@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: BSD-3-Clause
 
 import React from "react"
-import { ReactComponent as TailscaleIcon } from "src/assets/icons/tailscale-icon.svg"
+import TailscaleIcon from "src/assets/icons/tailscale-icon.svg?react"
 import LoginToggle from "src/components/login-toggle"
 import DeviceDetailsView from "src/components/views/device-details-view"
 import DisconnectedView from "src/components/views/disconnected-view"
@@ -11,8 +11,8 @@ import LoginView from "src/components/views/login-view"
 import SSHView from "src/components/views/ssh-view"
 import SubnetRouterView from "src/components/views/subnet-router-view"
 import { UpdatingView } from "src/components/views/updating-view"
-import useAuth, { AuthResponse } from "src/hooks/auth"
-import { Feature, featureDescription, NodeData } from "src/types"
+import useAuth, { AuthResponse, canEdit } from "src/hooks/auth"
+import { Feature, NodeData, featureDescription } from "src/types"
 import Card from "src/ui/card"
 import EmptyState from "src/ui/empty-state"
 import LoadingDots from "src/ui/loading-dots"
@@ -56,16 +56,19 @@ function WebClient({
         <Header node={node} auth={auth} newSession={newSession} />
         <Switch>
           <Route path="/">
-            <HomeView readonly={!auth.canManageNode} node={node} />
+            <HomeView node={node} auth={auth} />
           </Route>
           <Route path="/details">
-            <DeviceDetailsView readonly={!auth.canManageNode} node={node} />
+            <DeviceDetailsView node={node} auth={auth} />
           </Route>
           <FeatureRoute path="/subnets" feature="advertise-routes" node={node}>
-            <SubnetRouterView readonly={!auth.canManageNode} node={node} />
+            <SubnetRouterView
+              readonly={!canEdit("subnets", auth)}
+              node={node}
+            />
           </FeatureRoute>
           <FeatureRoute path="/ssh" feature="ssh" node={node}>
-            <SSHView readonly={!auth.canManageNode} node={node} />
+            <SSHView readonly={!canEdit("ssh", auth)} node={node} />
           </FeatureRoute>
           {/* <Route path="/serve">Share local content</Route> */}
           <FeatureRoute path="/update" feature="auto-update" node={node}>

client/web/src/components/exit-node-selector.tsx

@@ -4,8 +4,8 @@
 import cx from "classnames"
 import React, { useCallback, useEffect, useMemo, useRef, useState } from "react"
 import { useAPI } from "src/api"
-import { ReactComponent as Check } from "src/assets/icons/check.svg"
-import { ReactComponent as ChevronDown } from "src/assets/icons/chevron-down.svg"
+import Check from "src/assets/icons/check.svg?react"
+import ChevronDown from "src/assets/icons/chevron-down.svg?react"
 import useExitNodes, {
   noExitNode,
   runAsExitNode,
@@ -180,7 +180,7 @@ export default function ExitNodeSelector({
       )}
       {pending && (
         <p className="text-white p-3">
-          Pending approval to run as exit node. This device won't be usable as
+          Pending approval to run as exit node. This device won’t be usable as
           an exit node until then.
         </p>
       )}

client/web/src/components/login-toggle.tsx

@@ -2,15 +2,17 @@
 // SPDX-License-Identifier: BSD-3-Clause
 
 import cx from "classnames"
-import React, { useCallback, useEffect, useState } from "react"
-import { ReactComponent as ChevronDown } from "src/assets/icons/chevron-down.svg"
-import { ReactComponent as Eye } from "src/assets/icons/eye.svg"
-import { ReactComponent as User } from "src/assets/icons/user.svg"
-import { AuthResponse, AuthType } from "src/hooks/auth"
+import React, { useCallback, useMemo, useState } from "react"
+import ChevronDown from "src/assets/icons/chevron-down.svg?react"
+import Eye from "src/assets/icons/eye.svg?react"
+import User from "src/assets/icons/user.svg?react"
+import { AuthResponse, hasAnyEditCapabilities } from "src/hooks/auth"
+import { useTSWebConnected } from "src/hooks/ts-web-connected"
 import { NodeData } from "src/types"
 import Button from "src/ui/button"
 import Popover from "src/ui/popover"
 import ProfilePic from "src/ui/profile-pic"
+import { assertNever, isHTTPS } from "src/utils/util"
 
 export default function LoginToggle({
   node,
@@ -22,12 +24,29 @@ export default function LoginToggle({
   newSession: () => Promise<void>
 }) {
   const [open, setOpen] = useState<boolean>(false)
+  const { tsWebConnected, checkTSWebConnection } = useTSWebConnected(
+    auth.serverMode,
+    node.IPv4
+  )
 
   return (
     <Popover
-      className="p-3 bg-white rounded-lg shadow flex flex-col gap-2 max-w-[317px]"
+      className="p-3 bg-white rounded-lg shadow flex flex-col max-w-[317px]"
       content={
-        <LoginPopoverContent node={node} auth={auth} newSession={newSession} />
+        auth.serverMode === "readonly" ? (
+          <ReadonlyModeContent auth={auth} />
+        ) : auth.serverMode === "login" ? (
+          <LoginModeContent
+            auth={auth}
+            node={node}
+            tsWebConnected={tsWebConnected}
+            checkTSWebConnection={checkTSWebConnection}
+          />
+        ) : auth.serverMode === "manage" ? (
+          <ManageModeContent auth={auth} node={node} newSession={newSession} />
+        ) : (
+          assertNever(auth.serverMode)
+        )
       }
       side="bottom"
       align="end"
@@ -35,216 +54,303 @@ export default function LoginToggle({
       onOpenChange={setOpen}
       asChild
     >
-      {!auth.canManageNode ? (
-        <button
-          className={cx(
-            "pl-3 py-1 bg-gray-700 rounded-full flex justify-start items-center h-[34px]",
-            { "pr-1": auth.viewerIdentity, "pr-3": !auth.viewerIdentity }
-          )}
-          onClick={() => setOpen(!open)}
-        >
-          <Eye />
-          <div className="text-white leading-snug ml-2 mr-1">Viewing</div>
-          <ChevronDown className="stroke-white w-[15px] h-[15px]" />
-          {auth.viewerIdentity && (
-            <ProfilePic
-              className="ml-2"
-              size="medium"
-              url={auth.viewerIdentity.profilePicUrl}
-            />
-          )}
-        </button>
-      ) : (
-        <div
-          className={cx(
-            "w-[34px] h-[34px] p-1 rounded-full justify-center items-center inline-flex hover:bg-gray-300",
-            {
-              "bg-transparent": !open,
-              "bg-gray-300": open,
-            }
-          )}
-        >
-          <button onClick={() => setOpen(!open)}>
-            <ProfilePic
-              size="medium"
-              url={auth.viewerIdentity?.profilePicUrl}
-            />
-          </button>
-        </div>
-      )}
+      <div>
+        {auth.authorized ? (
+          <TriggerWhenManaging auth={auth} open={open} setOpen={setOpen} />
+        ) : (
+          <TriggerWhenReading auth={auth} open={open} setOpen={setOpen} />
+        )}
+      </div>
     </Popover>
   )
 }
 
-function LoginPopoverContent({
+/**
+ * TriggerWhenManaging is displayed as the trigger for the login popover
+ * when the user has an active authorized managment session.
+ */
+function TriggerWhenManaging({
+  auth,
+  open,
+  setOpen,
+}: {
+  auth: AuthResponse
+  open: boolean
+  setOpen: (next: boolean) => void
+}) {
+  return (
+    <div
+      className={cx(
+        "w-[34px] h-[34px] p-1 rounded-full justify-center items-center inline-flex hover:bg-gray-300",
+        {
+          "bg-transparent": !open,
+          "bg-gray-300": open,
+        }
+      )}
+    >
+      <button onClick={() => setOpen(!open)}>
+        <ProfilePic size="medium" url={auth.viewerIdentity?.profilePicUrl} />
+      </button>
+    </div>
+  )
+}
+
+/**
+ * TriggerWhenReading is displayed as the trigger for the login popover
+ * when the user is currently in read mode (doesn't have an authorized
+ * management session).
+ */
+function TriggerWhenReading({
+  auth,
+  open,
+  setOpen,
+}: {
+  auth: AuthResponse
+  open: boolean
+  setOpen: (next: boolean) => void
+}) {
+  return (
+    <button
+      className={cx(
+        "pl-3 py-1 bg-gray-700 rounded-full flex justify-start items-center h-[34px]",
+        { "pr-1": auth.viewerIdentity, "pr-3": !auth.viewerIdentity }
+      )}
+      onClick={() => setOpen(!open)}
+    >
+      <Eye />
+      <div className="text-white leading-snug ml-2 mr-1">Viewing</div>
+      <ChevronDown className="stroke-white w-[15px] h-[15px]" />
+      {auth.viewerIdentity && (
+        <ProfilePic
+          className="ml-2"
+          size="medium"
+          url={auth.viewerIdentity.profilePicUrl}
+        />
+      )}
+    </button>
+  )
+}
+
+/**
+ * PopoverContentHeader is the header for the login popover.
+ */
+function PopoverContentHeader({ auth }: { auth: AuthResponse }) {
+  return (
+    <div className="text-black text-sm font-medium leading-tight mb-1">
+      {auth.authorized ? "Managing" : "Viewing"}
+      {auth.viewerIdentity && ` as ${auth.viewerIdentity.loginName}`}
+    </div>
+  )
+}
+
+/**
+ * PopoverContentFooter is the footer for the login popover.
+ */
+function PopoverContentFooter({ auth }: { auth: AuthResponse }) {
+  return auth.viewerIdentity ? (
+    <>
+      <hr className="my-2" />
+      <div className="flex items-center">
+        <User className="flex-shrink-0" />
+        <p className="text-gray-500 text-xs ml-2">
+          We recognize you because you are accessing this page from{" "}
+          <span className="font-medium">
+            {auth.viewerIdentity.nodeName || auth.viewerIdentity.nodeIP}
+          </span>
+        </p>
+      </div>
+    </>
+  ) : null
+}
+
+/**
+ * ReadonlyModeContent is the body of the login popover when the web
+ * client is being run in "readonly" server mode.
+ */
+function ReadonlyModeContent({ auth }: { auth: AuthResponse }) {
+  return (
+    <>
+      <PopoverContentHeader auth={auth} />
+      <p className="text-gray-500 text-xs">
+        This web interface is running in read-only mode.{" "}
+        <a
+          href="https://tailscale.com/s/web-client-read-only"
+          className="text-blue-700"
+          target="_blank"
+          rel="noreferrer"
+        >
+          Learn more &rarr;
+        </a>
+      </p>
+      <PopoverContentFooter auth={auth} />
+    </>
+  )
+}
+
+/**
+ * LoginModeContent is the body of the login popover when the web
+ * client is being run in "login" server mode.
+ */
+function LoginModeContent({
   node,
+  auth,
+  tsWebConnected,
+  checkTSWebConnection,
+}: {
+  node: NodeData
+  auth: AuthResponse
+  tsWebConnected: boolean
+  checkTSWebConnection: () => void
+}) {
+  const https = isHTTPS()
+  // We can't run the ts web connection test when the webpage is loaded
+  // over HTTPS. So in this case, we default to presenting a login button
+  // with some helper text reminding the user to check their connection
+  // themselves.
+  const hasACLAccess = https || tsWebConnected
+
+  const hasEditCaps = useMemo(() => {
+    if (!auth.viewerIdentity) {
+      // If not connected to login client over tailscale, we won't know the viewer's
+      // identity. So we must assume they may be able to edit something and have the
+      // management client handle permissions once the user gets there.
+      return true
+    }
+    return hasAnyEditCapabilities(auth)
+  }, [auth])
+
+  const handleLogin = useCallback(() => {
+    // Must be connected over Tailscale to log in.
+    // Send user to Tailscale IP and start check mode
+    const manageURL = `http://${node.IPv4}:5252/?check=now`
+    if (window.self !== window.top) {
+      // If we're inside an iframe, open management client in new window.
+      window.open(manageURL, "_blank")
+    } else {
+      window.location.href = manageURL
+    }
+  }, [node.IPv4])
+
+  return (
+    <div
+      onMouseEnter={
+        hasEditCaps && !hasACLAccess ? checkTSWebConnection : undefined
+      }
+    >
+      <PopoverContentHeader auth={auth} />
+      {!hasACLAccess || !hasEditCaps ? (
+        <>
+          <p className="text-gray-500 text-xs">
+            {!hasEditCaps ? (
+              // ACLs allow access, but user isn't allowed to edit any features,
+              // restricted to readonly. No point in sending them over to the
+              // tailscaleIP:5252 address.
+              <>
+                You don’t have permission to make changes to this device, but
+                you can view most of its details.
+              </>
+            ) : !node.ACLAllowsAnyIncomingTraffic ? (
+              // Tailnet ACLs don't allow access to anyone.
+              <>
+                The current tailnet policy file does not allow connecting to
+                this device.
+              </>
+            ) : (
+              // ACLs don't allow access to this user specifically.
+              <>
+                Cannot access this device’s Tailscale IP. Make sure you are
+                connected to your tailnet, and that your policy file allows
+                access.
+              </>
+            )}{" "}
+            <a
+              href="https://tailscale.com/s/web-client-access"
+              className="text-blue-700"
+              target="_blank"
+              rel="noreferrer"
+            >
+              Learn more &rarr;
+            </a>
+          </p>
+        </>
+      ) : (
+        // User can connect to Tailcale IP; sign in when ready.
+        <>
+          <p className="text-gray-500 text-xs">
+            You can see most of this device’s details. To make changes, you need
+            to sign in.
+          </p>
+          {https && (
+            // we don't know if the user can connect over TS, so
+            // provide extra tips in case they have trouble.
+            <p className="text-gray-500 text-xs font-semibold pt-2">
+              Make sure you are connected to your tailnet, and that your policy
+              file allows access.
+            </p>
+          )}
+          <SignInButton auth={auth} onClick={handleLogin} />
+        </>
+      )}
+      <PopoverContentFooter auth={auth} />
+    </div>
+  )
+}
+
+/**
+ * ManageModeContent is the body of the login popover when the web
+ * client is being run in "manage" server mode.
+ */
+function ManageModeContent({
   auth,
   newSession,
 }: {
   node: NodeData
   auth: AuthResponse
-  newSession: () => Promise<void>
+  newSession: () => void
 }) {
-  /**
-   * canConnectOverTS indicates whether the current viewer
-   * is able to hit the node's web client that's being served
-   * at http://${node.IP}:5252. If false, this means that the
-   * viewer must connect to the correct tailnet before being
-   * able to sign in.
-   */
-  const [canConnectOverTS, setCanConnectOverTS] = useState<boolean>(false)
-  const [isRunningCheck, setIsRunningCheck] = useState<boolean>(false)
-
-  // Whether the current page is loaded over HTTPS.
-  // If it is, then the connectivity check to the management client
-  // will fail with a mixed-content error.
-  const isHTTPS = window.location.protocol === "https:"
-
-  const checkTSConnection = useCallback(() => {
-    if (auth.viewerIdentity || isHTTPS) {
-      // Skip the connectivity check if we either already know we're connected over Tailscale,
-      // or know the connectivity check will fail because the current page is loaded over HTTPS.
-      setCanConnectOverTS(true)
-      return
-    }
-    // Otherwise, test connection to the ts IP.
-    if (isRunningCheck) {
-      return // already checking
-    }
-    setIsRunningCheck(true)
-    fetch(`http://${node.IPv4}:5252/ok`, { mode: "no-cors" })
-      .then(() => {
-        setCanConnectOverTS(true)
-        setIsRunningCheck(false)
-      })
-      .catch(() => setIsRunningCheck(false))
-  }, [auth.viewerIdentity, isRunningCheck, node.IPv4, isHTTPS])
-
-  /**
-   * Checking connection for first time on page load.
-   *
-   * While not connected, we check again whenever the mouse
-   * enters the popover component, to pick up on the user
-   * leaving to turn on Tailscale then returning to the view.
-   * See `onMouseEnter` on the div below.
-   */
-  // eslint-disable-next-line react-hooks/exhaustive-deps
-  useEffect(() => checkTSConnection(), [])
-
-  const handleSignInClick = useCallback(() => {
-    if (auth.viewerIdentity && auth.serverMode === "manage") {
-      if (window.self !== window.top) {
-        // if we're inside an iframe, start session in new window
-        let url = new URL(window.location.href)
-        url.searchParams.set("check", "now")
-        window.open(url, "_blank")
-      } else {
-        newSession()
-      }
+  const handleLogin = useCallback(() => {
+    if (window.self !== window.top) {
+      // If we're inside an iframe, start session in new window.
+      let url = new URL(window.location.href)
+      url.searchParams.set("check", "now")
+      window.open(url, "_blank")
     } else {
-      // Must be connected over Tailscale to log in.
-      // Send user to Tailscale IP and start check mode
-      const manageURL = `http://${node.IPv4}:5252/?check=now`
-      if (window.self !== window.top) {
-        // if we're inside an iframe, open management client in new window
-        window.open(manageURL, "_blank")
-      } else {
-        window.location.href = manageURL
-      }
+      newSession()
     }
-  }, [auth.viewerIdentity, auth.serverMode, newSession, node.IPv4])
+  }, [newSession])
+
+  const hasAnyPermissions = useMemo(() => hasAnyEditCapabilities(auth), [auth])
 
   return (
-    <div onMouseEnter={!canConnectOverTS ? checkTSConnection : undefined}>
-      <div className="text-black text-sm font-medium leading-tight mb-1">
-        {!auth.canManageNode ? "Viewing" : "Managing"}
-        {auth.viewerIdentity && ` as ${auth.viewerIdentity.loginName}`}
-      </div>
-      {!auth.canManageNode && (
-        <>
-          {!auth.viewerIdentity ? (
-            // User is not connected over Tailscale.
-            // These states are only possible on the login client.
-            <>
-              {!canConnectOverTS ? (
-                <>
-                  <p className="text-gray-500 text-xs">
-                    {!node.ACLAllowsAnyIncomingTraffic ? (
-                      // Tailnet ACLs don't allow access.
-                      <>
-                        The current tailnet policy file does not allow
-                        connecting to this device.
-                      </>
-                    ) : (
-                      // ACLs allow access, but user can't connect.
-                      <>
-                        Cannot access this device's Tailscale IP. Make sure you
-                        are connected to your tailnet, and that your policy file
-                        allows access.
-                      </>
-                    )}{" "}
-                    <a
-                      href="https://tailscale.com/s/web-client-connection"
-                      className="text-blue-700"
-                      target="_blank"
-                      rel="noreferrer"
-                    >
-                      Learn more &rarr;
-                    </a>
-                  </p>
-                </>
-              ) : (
-                // User can connect to Tailcale IP; sign in when ready.
-                <>
-                  <p className="text-gray-500 text-xs">
-                    You can see most of this device's details. To make changes,
-                    you need to sign in.
-                  </p>
-                  {isHTTPS && (
-                    // we don't know if the user can connect over TS, so
-                    // provide extra tips in case they have trouble.
-                    <p className="text-gray-500 text-xs font-semibold pt-2">
-                      Make sure you are connected to your tailnet, and that your
-                      policy file allows access.
-                    </p>
-                  )}
-                  <SignInButton auth={auth} onClick={handleSignInClick} />
-                </>
-              )}
-            </>
-          ) : auth.authNeeded === AuthType.tailscale ? (
-            // User is connected over Tailscale, but needs to complete check mode.
-            <>
-              <p className="text-gray-500 text-xs">
-                To make changes, sign in to confirm your identity. This extra
-                step helps us keep your device secure.
-              </p>
-              <SignInButton auth={auth} onClick={handleSignInClick} />
-            </>
-          ) : (
-            // User is connected over tailscale, but doesn't have permission to manage.
+    <>
+      <PopoverContentHeader auth={auth} />
+      {!auth.authorized &&
+        (hasAnyPermissions ? (
+          // User is connected over Tailscale, but needs to complete check mode.
+          <>
             <p className="text-gray-500 text-xs">
-              You don’t have permission to make changes to this device, but you
-              can view most of its details.
+              To make changes, sign in to confirm your identity. This extra step
+              helps us keep your device secure.
             </p>
-          )}
-        </>
-      )}
-      {auth.viewerIdentity && (
-        <>
-          <hr className="my-2" />
-          <div className="flex items-center">
-            <User className="flex-shrink-0" />
-            <p className="text-gray-500 text-xs ml-2">
-              We recognize you because you are accessing this page from{" "}
-              <span className="font-medium">
-                {auth.viewerIdentity.nodeName || auth.viewerIdentity.nodeIP}
-              </span>
-            </p>
-          </div>
-        </>
-      )}
-    </div>
+            <SignInButton auth={auth} onClick={handleLogin} />
+          </>
+        ) : (
+          // User is connected over tailscale, but doesn't have permission to manage.
+          <p className="text-gray-500 text-xs">
+            You don’t have permission to make changes to this device, but you
+            can view most of its details.{" "}
+            <a
+              href="https://tailscale.com/s/web-client-access"
+              className="text-blue-700"
+              target="_blank"
+              rel="noreferrer"
+            >
+              Learn more &rarr;
+            </a>
+          </p>
+        ))}
+      <PopoverContentFooter auth={auth} />
+    </>
   )
 }
 

client/web/src/components/update-available.tsx

@@ -61,7 +61,7 @@ export function ChangelogText({ version }: { version?: string }) {
       <a href="https://tailscale.com/changelog/" className="link">
         release notes
       </a>{" "}
-      to find out what's new!
+      to find out what’s new!
     </>
   )
 }

client/web/src/components/views/device-details-view.tsx

@@ -8,6 +8,7 @@ import ACLTag from "src/components/acl-tag"
 import * as Control from "src/components/control-components"
 import NiceIP from "src/components/nice-ip"
 import { UpdateAvailableNotification } from "src/components/update-available"
+import { AuthResponse, canEdit } from "src/hooks/auth"
 import { NodeData } from "src/types"
 import Button from "src/ui/button"
 import Card from "src/ui/card"
@@ -16,11 +17,11 @@ import QuickCopy from "src/ui/quick-copy"
 import { useLocation } from "wouter"
 
 export default function DeviceDetailsView({
-  readonly,
   node,
+  auth,
 }: {
-  readonly: boolean
   node: NodeData
+  auth: AuthResponse
 }) {
   return (
     <>
@@ -37,11 +38,11 @@ export default function DeviceDetailsView({
                 })}
               />
             </div>
-            {!readonly && <DisconnectDialog />}
+            {canEdit("account", auth) && <DisconnectDialog />}
           </div>
         </Card>
         {node.Features["auto-update"] &&
-          !readonly &&
+          canEdit("account", auth) &&
           node.ClientVersion &&
           !node.ClientVersion.RunningLatest && (
             <UpdateAvailableNotification details={node.ClientVersion} />

client/web/src/components/views/disconnected-view.tsx

@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: BSD-3-Clause
 
 import React from "react"
-import { ReactComponent as TailscaleIcon } from "src/assets/icons/tailscale-icon.svg"
+import TailscaleIcon from "src/assets/icons/tailscale-icon.svg?react"
 
 /**
  * DisconnectedView is rendered after node logout.

client/web/src/components/views/home-view.tsx

@@ -4,21 +4,22 @@
 import cx from "classnames"
 import React, { useMemo } from "react"
 import { apiFetch } from "src/api"
-import { ReactComponent as ArrowRight } from "src/assets/icons/arrow-right.svg"
-import { ReactComponent as Machine } from "src/assets/icons/machine.svg"
+import ArrowRight from "src/assets/icons/arrow-right.svg?react"
+import Machine from "src/assets/icons/machine.svg?react"
 import AddressCard from "src/components/address-copy-card"
 import ExitNodeSelector from "src/components/exit-node-selector"
+import { AuthResponse, canEdit } from "src/hooks/auth"
 import { NodeData } from "src/types"
 import Card from "src/ui/card"
 import { pluralize } from "src/utils/util"
 import { Link, useLocation } from "wouter"
 
 export default function HomeView({
-  readonly,
   node,
+  auth,
 }: {
-  readonly: boolean
   node: NodeData
+  auth: AuthResponse
 }) {
   const [allSubnetRoutes, pendingSubnetRoutes] = useMemo(
     () => [
@@ -63,7 +64,11 @@ export default function HomeView({
         </div>
         {(node.Features["advertise-exit-node"] ||
           node.Features["use-exit-node"]) && (
-          <ExitNodeSelector className="mb-5" node={node} disabled={readonly} />
+          <ExitNodeSelector
+            className="mb-5"
+            node={node}
+            disabled={!canEdit("exitnodes", auth)}
+          />
         )}
         <Link
           className="link font-medium"

client/web/src/components/views/login-view.tsx

@@ -3,7 +3,7 @@
 
 import React, { useState } from "react"
 import { useAPI } from "src/api"
-import { ReactComponent as TailscaleIcon } from "src/assets/icons/tailscale-icon.svg"
+import TailscaleIcon from "src/assets/icons/tailscale-icon.svg?react"
 import { NodeData } from "src/types"
 import Button from "src/ui/button"
 import Collapsible from "src/ui/collapsible"
@@ -41,7 +41,7 @@ export default function LoginView({ data }: { data: NodeData }) {
         <>
           <div className="mb-6">
             <p className="text-gray-700">
-              Your device's key has expired. Reauthenticate this device by
+              Your device’s key has expired. Reauthenticate this device by
               logging in again, or{" "}
               <a
                 href="https://tailscale.com/kb/1028/key-expiry"

client/web/src/components/views/subnet-router-view.tsx

@@ -4,9 +4,9 @@
 import cx from "classnames"
 import React, { useCallback, useMemo, useState } from "react"
 import { useAPI } from "src/api"
-import { ReactComponent as CheckCircle } from "src/assets/icons/check-circle.svg"
-import { ReactComponent as Clock } from "src/assets/icons/clock.svg"
-import { ReactComponent as Plus } from "src/assets/icons/plus.svg"
+import CheckCircle from "src/assets/icons/check-circle.svg?react"
+import Clock from "src/assets/icons/clock.svg?react"
+import Plus from "src/assets/icons/plus.svg?react"
 import * as Control from "src/components/control-components"
 import { NodeData } from "src/types"
 import Button from "src/ui/button"

client/web/src/components/views/updating-view.tsx

@@ -2,8 +2,8 @@
 // SPDX-License-Identifier: BSD-3-Clause
 
 import React from "react"
-import { ReactComponent as CheckCircleIcon } from "src/assets/icons/check-circle.svg"
-import { ReactComponent as XCircleIcon } from "src/assets/icons/x-circle.svg"
+import CheckCircleIcon from "src/assets/icons/check-circle.svg?react"
+import XCircleIcon from "src/assets/icons/x-circle.svg?react"
 import { ChangelogText } from "src/components/update-available"
 import { UpdateState, useInstallUpdate } from "src/hooks/self-update"
 import { VersionInfo } from "src/types"
@@ -35,7 +35,7 @@ export function UpdatingView({
             <Spinner size="sm" className="text-gray-400" />
             <h1 className="text-2xl m-3">Update in progress</h1>
             <p className="text-gray-400">
-              The update shouldn't take more than a couple of minutes. Once it's
+              The update shouldn’t take more than a couple of minutes. Once it’s
               completed, you will be asked to log in again.
             </p>
           </>

client/web/src/hooks/auth.ts

@@ -4,25 +4,50 @@
 import { useCallback, useEffect, useState } from "react"
 import { apiFetch, setSynoToken } from "src/api"
 
-export enum AuthType {
-  synology = "synology",
-  tailscale = "tailscale",
-}
-
 export type AuthResponse = {
-  authNeeded?: AuthType
-  canManageNode: boolean
-  serverMode: "login" | "manage"
+  serverMode: AuthServerMode
+  authorized: boolean
   viewerIdentity?: {
     loginName: string
     nodeName: string
     nodeIP: string
     profilePicUrl?: string
+    capabilities: { [key in PeerCapability]: boolean }
   }
+  needsSynoAuth?: boolean
 }
 
-// useAuth reports and refreshes Tailscale auth status
-// for the web client.
+export type AuthServerMode = "login" | "readonly" | "manage"
+
+export type PeerCapability = "*" | "ssh" | "subnets" | "exitnodes" | "account"
+
+/**
+ * canEdit reports whether the given auth response specifies that the viewer
+ * has the ability to edit the given capability.
+ */
+export function canEdit(cap: PeerCapability, auth: AuthResponse): boolean {
+  if (!auth.authorized || !auth.viewerIdentity) {
+    return false
+  }
+  if (auth.viewerIdentity.capabilities["*"] === true) {
+    return true // can edit all features
+  }
+  return auth.viewerIdentity.capabilities[cap] === true
+}
+
+/**
+ * hasAnyEditCapabilities reports whether the given auth response specifies
+ * that the viewer has at least one edit capability. If this is true, the
+ * user is able to go through the auth flow to authenticate a management
+ * session.
+ */
+export function hasAnyEditCapabilities(auth: AuthResponse): boolean {
+  return Object.values(auth.viewerIdentity?.capabilities || {}).includes(true)
+}
+
+/**
+ * useAuth reports and refreshes Tailscale auth status for the web client.
+ */
 export default function useAuth() {
   const [data, setData] = useState<AuthResponse>()
   const [loading, setLoading] = useState<boolean>(true)
@@ -33,18 +58,16 @@ export default function useAuth() {
     return apiFetch<AuthResponse>("/auth", "GET")
       .then((d) => {
         setData(d)
-        switch (d.authNeeded) {
-          case AuthType.synology:
-            fetch("/webman/login.cgi")
-              .then((r) => r.json())
-              .then((a) => {
-                setSynoToken(a.SynoToken)
-                setRanSynoAuth(true)
-                setLoading(false)
-              })
-            break
-          default:
-            setLoading(false)
+        if (d.needsSynoAuth) {
+          fetch("/webman/login.cgi")
+            .then((r) => r.json())
+            .then((a) => {
+              setSynoToken(a.SynoToken)
+              setRanSynoAuth(true)
+              setLoading(false)
+            })
+        } else {
+          setLoading(false)
         }
         return d
       })
@@ -72,8 +95,13 @@ export default function useAuth() {
 
   useEffect(() => {
     loadAuth().then((d) => {
+      if (!d) {
+        return
+      }
       if (
-        !d?.canManageNode &&
+        !d.authorized &&
+        hasAnyEditCapabilities(d) &&
+        // Start auth flow immediately if browser has requested it.
         new URLSearchParams(window.location.search).get("check") === "now"
       ) {
         newSession()

client/web/src/hooks/ts-web-connected.ts

@@ -0,0 +1,46 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+import { useCallback, useEffect, useState } from "react"
+import { isHTTPS } from "src/utils/util"
+import { AuthServerMode } from "./auth"
+
+/**
+ * useTSWebConnected hook is used to check whether the browser is able to
+ * connect to the web client served at http://${nodeIPv4}:5252
+ */
+export function useTSWebConnected(mode: AuthServerMode, nodeIPv4: string) {
+  const [tsWebConnected, setTSWebConnected] = useState<boolean>(
+    mode === "manage" // browser already on the web client
+  )
+  const [isLoading, setIsLoading] = useState<boolean>(false)
+
+  const checkTSWebConnection = useCallback(() => {
+    if (mode === "manage") {
+      // Already connected to the web client.
+      setTSWebConnected(true)
+      return
+    }
+    if (isHTTPS()) {
+      // When page is loaded over HTTPS, the connectivity check will always
+      // fail with a mixed-content error. In this case don't bother doing
+      // the check.
+      return
+    }
+    if (isLoading) {
+      return // already checking
+    }
+    setIsLoading(true)
+    fetch(`http://${nodeIPv4}:5252/ok`, { mode: "no-cors" })
+      .then(() => {
+        setTSWebConnected(true)
+        setIsLoading(false)
+      })
+      .catch(() => setIsLoading(false))
+  }, [isLoading, mode, nodeIPv4])
+
+  // eslint-disable-next-line react-hooks/exhaustive-deps
+  useEffect(() => checkTSWebConnection(), []) // checking connection for first time on page load
+
+  return { tsWebConnected, checkTSWebConnection, isLoading }
+}

client/web/src/ui/collapsible.tsx

@@ -3,7 +3,7 @@
 
 import * as Primitive from "@radix-ui/react-collapsible"
 import React, { useState } from "react"
-import { ReactComponent as ChevronDown } from "src/assets/icons/chevron-down.svg"
+import ChevronDown from "src/assets/icons/chevron-down.svg?react"
 
 type CollapsibleProps = {
   trigger?: string

client/web/src/ui/dialog.tsx

@@ -4,7 +4,7 @@
 import * as DialogPrimitive from "@radix-ui/react-dialog"
 import cx from "classnames"
 import React, { Component, ComponentProps, FormEvent } from "react"
-import { ReactComponent as X } from "src/assets/icons/x.svg"
+import X from "src/assets/icons/x.svg?react"
 import Button from "src/ui/button"
 import PortalContainerContext from "src/ui/portal-container-context"
 import { isObject } from "src/utils/util"

client/web/src/ui/search-input.tsx

@@ -3,7 +3,7 @@
 
 import cx from "classnames"
 import React, { forwardRef, InputHTMLAttributes } from "react"
-import { ReactComponent as Search } from "src/assets/icons/search.svg"
+import Search from "src/assets/icons/search.svg?react"
 
 type Props = {
   className?: string

client/web/src/ui/toaster.tsx

@@ -10,7 +10,7 @@ import React, {
   useState,
 } from "react"
 import { createPortal } from "react-dom"
-import { ReactComponent as X } from "src/assets/icons/x.svg"
+import X from "src/assets/icons/x.svg?react"
 import { noop } from "src/utils/util"
 import { create } from "zustand"
 import { shallow } from "zustand/shallow"

client/web/src/utils/util.ts

@@ -49,3 +49,10 @@ export function isPromise<T = unknown>(val: unknown): val is Promise<T> {
   }
   return typeof val === "object" && "then" in val
 }
+
+/**
+ * isHTTPS reports whether the current page is loaded over HTTPS.
+ */
+export function isHTTPS() {
+  return window.location.protocol === "https:"
+}

client/web/tailwind.config.js

@@ -1,7 +1,7 @@
-const plugin = require("tailwindcss/plugin")
-const styles = require("./styles.json")
+import plugin from "tailwindcss/plugin"
+import styles from "./styles.json"
 
-module.exports = {
+const config = {
   theme: {
     screens: {
       sm: "420px",
@@ -96,20 +96,22 @@ module.exports = {
   plugins: [
     plugin(function ({ addVariant }) {
       addVariant("state-open", [
-        '&[data-state="open"]',
-        '[data-state="open"] &',
+        "&[data-state=“open”]",
+        "[data-state=“open”] &",
       ])
       addVariant("state-closed", [
-        '&[data-state="closed"]',
-        '[data-state="closed"] &',
+        "&[data-state=“closed”]",
+        "[data-state=“closed”] &",
       ])
       addVariant("state-delayed-open", [
-        '&[data-state="delayed-open"]',
-        '[data-state="delayed-open"] &',
+        "&[data-state=“delayed-open”]",
+        "[data-state=“delayed-open”] &",
       ])
-      addVariant("state-active", ['&[data-state="active"]'])
-      addVariant("state-inactive", ['&[data-state="inactive"]'])
+      addVariant("state-active", ["&[data-state=“active”]"])
+      addVariant("state-inactive", ["&[data-state=“inactive”]"])
     }),
   ],
   content: ["./src/**/*.html", "./src/**/*.{ts,tsx}", "./index.html"],
 }
+
+export default config

client/web/tsconfig.json

@@ -5,6 +5,7 @@
     "module": "ES2020",
     "strict": true,
     "sourceMap": true,
+    "skipLibCheck": true,
     "isolatedModules": true,
     "moduleResolution": "node",
     "forceConsistentCasingInFileNames": true,

client/web/vite.config.ts

@@ -1,6 +1,5 @@
 /// <reference types="vitest" />
 import { createLogger, defineConfig } from "vite"
-import rewrite from "vite-plugin-rewrite-all"
 import svgr from "vite-plugin-svgr"
 import paths from "vite-tsconfig-paths"
 
@@ -24,11 +23,6 @@ export default defineConfig({
   plugins: [
     paths(),
     svgr(),
-    // By default, the Vite dev server doesn't handle dots
-    // in path names and treats them as static files.
-    // This plugin changes Vite's routing logic to fix this.
-    // See: https://github.com/vitejs/vite/issues/2415
-    rewrite(),
   ],
   build: {
     outDir: "build",

client/web/web.go

@@ -95,6 +95,14 @@ const (
 	// In this mode, API calls are authenticated via platform auth.
 	LoginServerMode ServerMode = "login"
 
+	// ReadOnlyServerMode is identical to LoginServerMode,
+	// but does not present a login button to switch to manage mode,
+	// even if the management client is running and reachable.
+	//
+	// This is designed for platforms where the device is configured by other means,
+	// such as Home Assistant's declarative YAML configuration.
+	ReadOnlyServerMode ServerMode = "readonly"
+
 	// ManageServerMode serves a management client for editing tailscale
 	// settings of a node.
 	//
@@ -154,7 +162,7 @@ type ServerOpts struct {
 // and not the lifespan of the web server.
 func NewServer(opts ServerOpts) (s *Server, err error) {
 	switch opts.Mode {
-	case LoginServerMode, ManageServerMode:
+	case LoginServerMode, ReadOnlyServerMode, ManageServerMode:
 		// valid types
 	case "":
 		return nil, fmt.Errorf("must specify a Mode")
@@ -207,10 +215,14 @@ func NewServer(opts ServerOpts) (s *Server, err error) {
 	// The client is secured by limiting the interface it listens on,
 	// or by authenticating requests before they reach the web client.
 	csrfProtect := csrf.Protect(s.csrfKey(), csrf.Secure(false))
-	if s.mode == LoginServerMode {
+	switch s.mode {
+	case LoginServerMode:
 		s.apiHandler = csrfProtect(http.HandlerFunc(s.serveLoginAPI))
 		metric = "web_login_client_initialization"
-	} else {
+	case ReadOnlyServerMode:
+		s.apiHandler = csrfProtect(http.HandlerFunc(s.serveLoginAPI))
+		metric = "web_readonly_client_initialization"
+	case ManageServerMode:
 		s.apiHandler = csrfProtect(http.HandlerFunc(s.serveAPI))
 		metric = "web_client_initialization"
 	}
@@ -433,18 +445,188 @@ func (s *Server) serveLoginAPI(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
-type authType string
+type apiHandler[data any] struct {
+	s *Server
+	w http.ResponseWriter
+	r *http.Request
 
-var (
-	synoAuth      authType = "synology"  // user needs a SynoToken for subsequent API calls
-	tailscaleAuth authType = "tailscale" // user needs to complete Tailscale check mode
-)
+	// permissionCheck allows for defining whether a requesting peer's
+	// capabilities grant them access to make the given data update.
+	// If permissionCheck reports false, the request fails as unauthorized.
+	permissionCheck func(data data, peer peerCapabilities) bool
+}
+
+// newHandler constructs a new api handler which restricts the given request
+// to the specified permission check. If the permission check fails for
+// the peer associated with the request, an unauthorized error is returned
+// to the client.
+func newHandler[data any](s *Server, w http.ResponseWriter, r *http.Request, permissionCheck func(data data, peer peerCapabilities) bool) *apiHandler[data] {
+	return &apiHandler[data]{
+		s:               s,
+		w:               w,
+		r:               r,
+		permissionCheck: permissionCheck,
+	}
+}
+
+// alwaysAllowed can be passed as the permissionCheck argument to newHandler
+// for requests that are always allowed to complete regardless of a peer's
+// capabilities.
+func alwaysAllowed[data any](_ data, _ peerCapabilities) bool { return true }
+
+func (a *apiHandler[data]) getPeer() (peerCapabilities, error) {
+	// TODO(tailscale/corp#16695,sonia): We also call StatusWithoutPeers and
+	// WhoIs when originally checking for a session from authorizeRequest.
+	// Would be nice if we could pipe those through to here so we don't end
+	// up having to re-call them to grab the peer capabilities.
+	status, err := a.s.lc.StatusWithoutPeers(a.r.Context())
+	if err != nil {
+		return nil, err
+	}
+	whois, err := a.s.lc.WhoIs(a.r.Context(), a.r.RemoteAddr)
+	if err != nil {
+		return nil, err
+	}
+	peer, err := toPeerCapabilities(status, whois)
+	if err != nil {
+		return nil, err
+	}
+	return peer, nil
+}
+
+type noBodyData any // empty type, for use from serveAPI for endpoints with empty body
+
+// handle runs the given handler if the source peer satisfies the
+// constraints for running this request.
+//
+// handle is expected for use when `data` type is empty, or set to
+// `noBodyData` in practice. For requests that expect JSON body data
+// to be attached, use handleJSON instead.
+func (a *apiHandler[data]) handle(h http.HandlerFunc) {
+	peer, err := a.getPeer()
+	if err != nil {
+		http.Error(a.w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	var body data // not used
+	if !a.permissionCheck(body, peer) {
+		http.Error(a.w, "not allowed", http.StatusUnauthorized)
+		return
+	}
+	h(a.w, a.r)
+}
+
+// handleJSON manages decoding the request's body JSON and passing
+// it on to the provided function if the source peer satisfies the
+// constraints for running this request.
+func (a *apiHandler[data]) handleJSON(h func(ctx context.Context, data data) error) {
+	defer a.r.Body.Close()
+	var body data
+	if err := json.NewDecoder(a.r.Body).Decode(&body); err != nil {
+		http.Error(a.w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	peer, err := a.getPeer()
+	if err != nil {
+		http.Error(a.w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	if !a.permissionCheck(body, peer) {
+		http.Error(a.w, "not allowed", http.StatusUnauthorized)
+		return
+	}
+
+	if err := h(a.r.Context(), body); err != nil {
+		http.Error(a.w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	a.w.WriteHeader(http.StatusOK)
+}
+
+// serveAPI serves requests for the web client api.
+// It should only be called by Server.ServeHTTP, via Server.apiHandler,
+// which protects the handler using gorilla csrf.
+func (s *Server) serveAPI(w http.ResponseWriter, r *http.Request) {
+	if r.Method == httpm.PATCH {
+		// Enforce that PATCH requests are always application/json.
+		if ct := r.Header.Get("Content-Type"); ct != "application/json" {
+			http.Error(w, "invalid request", http.StatusBadRequest)
+			return
+		}
+	}
+
+	w.Header().Set("X-CSRF-Token", csrf.Token(r))
+	path := strings.TrimPrefix(r.URL.Path, "/api")
+	switch {
+	case path == "/data" && r.Method == httpm.GET:
+		newHandler[noBodyData](s, w, r, alwaysAllowed).
+			handle(s.serveGetNodeData)
+		return
+	case path == "/exit-nodes" && r.Method == httpm.GET:
+		newHandler[noBodyData](s, w, r, alwaysAllowed).
+			handle(s.serveGetExitNodes)
+		return
+	case path == "/routes" && r.Method == httpm.POST:
+		peerAllowed := func(d postRoutesRequest, p peerCapabilities) bool {
+			if d.SetExitNode && !p.canEdit(capFeatureExitNodes) {
+				return false
+			} else if d.SetRoutes && !p.canEdit(capFeatureSubnets) {
+				return false
+			}
+			return true
+		}
+		newHandler[postRoutesRequest](s, w, r, peerAllowed).
+			handleJSON(s.servePostRoutes)
+		return
+	case path == "/device-details-click" && r.Method == httpm.POST:
+		newHandler[noBodyData](s, w, r, alwaysAllowed).
+			handle(s.serveDeviceDetailsClick)
+		return
+	case path == "/local/v0/logout" && r.Method == httpm.POST:
+		peerAllowed := func(_ noBodyData, peer peerCapabilities) bool {
+			return peer.canEdit(capFeatureAccount)
+		}
+		newHandler[noBodyData](s, w, r, peerAllowed).
+			handle(s.proxyRequestToLocalAPI)
+		return
+	case path == "/local/v0/prefs" && r.Method == httpm.PATCH:
+		peerAllowed := func(data maskedPrefs, peer peerCapabilities) bool {
+			if data.RunSSHSet && !peer.canEdit(capFeatureSSH) {
+				return false
+			}
+			return true
+		}
+		newHandler[maskedPrefs](s, w, r, peerAllowed).
+			handleJSON(s.serveUpdatePrefs)
+		return
+	case path == "/local/v0/update/check" && r.Method == httpm.GET:
+		newHandler[noBodyData](s, w, r, alwaysAllowed).
+			handle(s.proxyRequestToLocalAPI)
+		return
+	case path == "/local/v0/update/check" && r.Method == httpm.POST:
+		peerAllowed := func(_ noBodyData, peer peerCapabilities) bool {
+			return peer.canEdit(capFeatureAccount)
+		}
+		newHandler[noBodyData](s, w, r, peerAllowed).
+			handle(s.proxyRequestToLocalAPI)
+		return
+	case path == "/local/v0/update/progress" && r.Method == httpm.POST:
+		newHandler[noBodyData](s, w, r, alwaysAllowed).
+			handle(s.proxyRequestToLocalAPI)
+		return
+	case path == "/local/v0/upload-client-metrics" && r.Method == httpm.POST:
+		newHandler[noBodyData](s, w, r, alwaysAllowed).
+			handle(s.proxyRequestToLocalAPI)
+		return
+	}
+	http.Error(w, "invalid endpoint", http.StatusNotFound)
+}
 
 type authResponse struct {
-	AuthNeeded     authType        `json:"authNeeded,omitempty"` // filled when user needs to complete a specific type of auth
-	CanManageNode  bool            `json:"canManageNode"`
-	ViewerIdentity *viewerIdentity `json:"viewerIdentity,omitempty"`
 	ServerMode     ServerMode      `json:"serverMode"`
+	Authorized     bool            `json:"authorized"` // has an authorized management session
+	ViewerIdentity *viewerIdentity `json:"viewerIdentity,omitempty"`
+	NeedsSynoAuth  bool            `json:"needsSynoAuth,omitempty"`
 }
 
 // viewerIdentity is the Tailscale identity of the source node
@@ -463,9 +645,11 @@ func (s *Server) serveAPIAuth(w http.ResponseWriter, r *http.Request) {
 	var resp authResponse
 	resp.ServerMode = s.mode
 	session, whois, status, sErr := s.getSession(r)
+	var caps peerCapabilities
 
 	if whois != nil {
-		caps, err := toPeerCapabilities(whois)
+		var err error
+		caps, err = toPeerCapabilities(status, whois)
 		if err != nil {
 			http.Error(w, sErr.Error(), http.StatusInternalServerError)
 			return
@@ -483,7 +667,7 @@ func (s *Server) serveAPIAuth(w http.ResponseWriter, r *http.Request) {
 
 	// First verify platform auth.
 	// If platform auth is needed, this should happen first.
-	if s.mode == LoginServerMode {
+	if s.mode == LoginServerMode || s.mode == ReadOnlyServerMode {
 		switch distro.Get() {
 		case distro.Synology:
 			authorized, err := authorizeSynology(r)
@@ -492,7 +676,7 @@ func (s *Server) serveAPIAuth(w http.ResponseWriter, r *http.Request) {
 				return
 			}
 			if !authorized {
-				resp.AuthNeeded = synoAuth
+				resp.NeedsSynoAuth = true
 				writeJSON(w, resp)
 				return
 			}
@@ -508,21 +692,17 @@ func (s *Server) serveAPIAuth(w http.ResponseWriter, r *http.Request) {
 
 	switch {
 	case sErr != nil && errors.Is(sErr, errNotUsingTailscale):
-		// Restricted to the readonly view, no auth action to take.
 		s.lc.IncrementCounter(r.Context(), "web_client_viewing_local", 1)
-		resp.AuthNeeded = ""
+		resp.Authorized = false // restricted to the readonly view
 	case sErr != nil && errors.Is(sErr, errNotOwner):
-		// Restricted to the readonly view, no auth action to take.
 		s.lc.IncrementCounter(r.Context(), "web_client_viewing_not_owner", 1)
-		resp.AuthNeeded = ""
+		resp.Authorized = false // restricted to the readonly view
 	case sErr != nil && errors.Is(sErr, errTaggedLocalSource):
-		// Restricted to the readonly view, no auth action to take.
 		s.lc.IncrementCounter(r.Context(), "web_client_viewing_local_tag", 1)
-		resp.AuthNeeded = ""
+		resp.Authorized = false // restricted to the readonly view
 	case sErr != nil && errors.Is(sErr, errTaggedRemoteSource):
-		// Restricted to the readonly view, no auth action to take.
 		s.lc.IncrementCounter(r.Context(), "web_client_viewing_remote_tag", 1)
-		resp.AuthNeeded = ""
+		resp.Authorized = false // restricted to the readonly view
 	case sErr != nil && !errors.Is(sErr, errNoSession):
 		// Any other error.
 		http.Error(w, sErr.Error(), http.StatusInternalServerError)
@@ -533,16 +713,26 @@ func (s *Server) serveAPIAuth(w http.ResponseWriter, r *http.Request) {
 		} else {
 			s.lc.IncrementCounter(r.Context(), "web_client_managing_remote", 1)
 		}
-		resp.CanManageNode = true
-		resp.AuthNeeded = ""
+		// User has a valid session. They're now authorized to edit if they
+		// have any edit capabilities. In practice, they won't be sent through
+		// the auth flow if they don't have edit caps, but their ACL granted
+		// permissions may change at any time. The frontend views and backend
+		// endpoints are always restricted to their current capabilities in
+		// addition to a valid session.
+		//
+		// But, we also check the caps here for a better user experience on
+		// the frontend login toggle, which uses resp.Authorized to display
+		// "viewing" vs "managing" copy. If they don't have caps, we want to
+		// display "viewing" even if they have a valid session.
+		resp.Authorized = !caps.isEmpty()
 	default:
-		// whois being nil implies local as the request did not come over Tailscale
 		if whois == nil || (whois.Node.StableID == status.Self.ID) {
+			// whois being nil implies local as the request did not come over Tailscale.
 			s.lc.IncrementCounter(r.Context(), "web_client_viewing_local", 1)
 		} else {
 			s.lc.IncrementCounter(r.Context(), "web_client_viewing_remote", 1)
 		}
-		resp.AuthNeeded = tailscaleAuth
+		resp.Authorized = false // not yet authorized
 	}
 
 	writeJSON(w, resp)
@@ -606,32 +796,6 @@ func (s *Server) serveAPIAuthSessionWait(w http.ResponseWriter, r *http.Request)
 	}
 }
 
-// serveAPI serves requests for the web client api.
-// It should only be called by Server.ServeHTTP, via Server.apiHandler,
-// which protects the handler using gorilla csrf.
-func (s *Server) serveAPI(w http.ResponseWriter, r *http.Request) {
-	w.Header().Set("X-CSRF-Token", csrf.Token(r))
-	path := strings.TrimPrefix(r.URL.Path, "/api")
-	switch {
-	case path == "/data" && r.Method == httpm.GET:
-		s.serveGetNodeData(w, r)
-		return
-	case path == "/exit-nodes" && r.Method == httpm.GET:
-		s.serveGetExitNodes(w, r)
-		return
-	case path == "/routes" && r.Method == httpm.POST:
-		s.servePostRoutes(w, r)
-		return
-	case path == "/device-details-click" && r.Method == httpm.POST:
-		s.serveDeviceDetailsClick(w, r)
-		return
-	case strings.HasPrefix(path, "/local/"):
-		s.proxyRequestToLocalAPI(w, r)
-		return
-	}
-	http.Error(w, "invalid endpoint", http.StatusNotFound)
-}
-
 type nodeData struct {
 	ID          tailcfg.StableNodeID
 	Status      string
@@ -868,6 +1032,23 @@ func (s *Server) serveGetExitNodes(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, exitNodes)
 }
 
+// maskedPrefs is the subset of ipn.MaskedPrefs that are
+// allowed to be editable via the web UI.
+type maskedPrefs struct {
+	RunSSHSet bool
+	RunSSH    bool
+}
+
+func (s *Server) serveUpdatePrefs(ctx context.Context, prefs maskedPrefs) error {
+	_, err := s.lc.EditPrefs(ctx, &ipn.MaskedPrefs{
+		RunSSHSet: prefs.RunSSHSet,
+		Prefs: ipn.Prefs{
+			RunSSH: prefs.RunSSH,
+		},
+	})
+	return err
+}
+
 type postRoutesRequest struct {
 	SetExitNode       bool // when set, UseExitNode and AdvertiseExitNode values are applied
 	SetRoutes         bool // when set, AdvertiseRoutes value is applied
@@ -876,18 +1057,10 @@ type postRoutesRequest struct {
 	AdvertiseRoutes   []string
 }
 
-func (s *Server) servePostRoutes(w http.ResponseWriter, r *http.Request) {
-	defer r.Body.Close()
-
-	var data postRoutesRequest
-	if err := json.NewDecoder(r.Body).Decode(&data); err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
-	prefs, err := s.lc.GetPrefs(r.Context())
+func (s *Server) servePostRoutes(ctx context.Context, data postRoutesRequest) error {
+	prefs, err := s.lc.GetPrefs(ctx)
 	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
+		return err
 	}
 	var currNonExitRoutes []string
 	var currAdvertisingExitNode bool
@@ -910,8 +1083,7 @@ func (s *Server) servePostRoutes(w http.ResponseWriter, r *http.Request) {
 	routesStr := strings.Join(data.AdvertiseRoutes, ",")
 	routes, err := netutil.CalcAdvertiseRoutes(routesStr, data.AdvertiseExitNode)
 	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
+		return err
 	}
 
 	hasExitNodeRoute := func(all []netip.Prefix) bool {
@@ -920,8 +1092,7 @@ func (s *Server) servePostRoutes(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if !data.UseExitNode.IsZero() && hasExitNodeRoute(routes) {
-		http.Error(w, "cannot use and advertise exit node at same time", http.StatusBadRequest)
-		return
+		return errors.New("cannot use and advertise exit node at same time")
 	}
 
 	// Make prefs update.
@@ -933,12 +1104,8 @@ func (s *Server) servePostRoutes(w http.ResponseWriter, r *http.Request) {
 			AdvertiseRoutes: routes,
 		},
 	}
-	if _, err := s.lc.EditPrefs(r.Context(), p); err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
-
-	w.WriteHeader(http.StatusOK)
+	_, err = s.lc.EditPrefs(ctx, p)
+	return err
 }
 
 // tailscaleUp starts the daemon with the provided options.
@@ -983,7 +1150,15 @@ func (s *Server) tailscaleUp(ctx context.Context, st *ipnstate.Status, opt tails
 		if !isRunning {
 			ipnOptions := ipn.Options{AuthKey: opt.AuthKey}
 			if opt.ControlURL != "" {
-				ipnOptions.UpdatePrefs = &ipn.Prefs{ControlURL: opt.ControlURL}
+				_, err := s.lc.EditPrefs(ctx, &ipn.MaskedPrefs{
+					Prefs: ipn.Prefs{
+						ControlURL: opt.ControlURL,
+					},
+					ControlURLSet: true,
+				})
+				if err != nil {
+					s.logf("edit prefs: %v", err)
+				}
 			}
 			if err := s.lc.Start(ctx, ipnOptions); err != nil {
 				s.logf("start: %v", err)
@@ -1077,26 +1252,12 @@ func (s *Server) serveDeviceDetailsClick(w http.ResponseWriter, r *http.Request)
 //
 // The web API request path is expected to exactly match a localapi path,
 // with prefix /api/local/ rather than /localapi/.
-//
-// If the localapi path is not included in localapiAllowlist,
-// the request is rejected.
 func (s *Server) proxyRequestToLocalAPI(w http.ResponseWriter, r *http.Request) {
 	path := strings.TrimPrefix(r.URL.Path, "/api/local")
 	if r.URL.Path == path { // missing prefix
 		http.Error(w, "invalid request", http.StatusBadRequest)
 		return
 	}
-	if r.Method == httpm.PATCH {
-		// enforce that PATCH requests are always application/json
-		if ct := r.Header.Get("Content-Type"); ct != "application/json" {
-			http.Error(w, "invalid request", http.StatusBadRequest)
-			return
-		}
-	}
-	if !slices.Contains(localapiAllowlist, path) {
-		http.Error(w, fmt.Sprintf("%s not allowed from localapi proxy", path), http.StatusForbidden)
-		return
-	}
 
 	localAPIURL := "http://" + apitype.LocalAPIHost + "/localapi" + path
 	req, err := http.NewRequestWithContext(r.Context(), r.Method, localAPIURL, r.Body)
@@ -1121,21 +1282,6 @@ func (s *Server) proxyRequestToLocalAPI(w http.ResponseWriter, r *http.Request)
 	}
 }
 
-// localapiAllowlist is an allowlist of localapi endpoints the
-// web client is allowed to proxy to the client's localapi.
-//
-// Rather than exposing all localapi endpoints over the proxy,
-// this limits to just the ones actually used from the web
-// client frontend.
-var localapiAllowlist = []string{
-	"/v0/logout",
-	"/v0/prefs",
-	"/v0/update/check",
-	"/v0/update/install",
-	"/v0/update/progress",
-	"/v0/upload-client-metrics",
-}
-
 // csrfKey returns a key that can be used for CSRF protection.
 // If an error occurs during key creation, the error is logged and the active process terminated.
 // If the server is running in CGI mode, the key is cached to disk and reused between requests.

client/web/web_test.go

@@ -4,6 +4,7 @@
 package web
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
 	"errors"
@@ -86,75 +87,172 @@ func TestQnapAuthnURL(t *testing.T) {
 
 // TestServeAPI tests the web client api's handling of
 //  1. invalid endpoint errors
-//  2. localapi proxy allowlist
+//  2. permissioning of api endpoints based on node capabilities
 func TestServeAPI(t *testing.T) {
+	selfTags := views.SliceOf([]string{"tag:server"})
+	self := &ipnstate.PeerStatus{ID: "self", Tags: &selfTags}
+	prefs := &ipn.Prefs{}
+
+	remoteUser := &tailcfg.UserProfile{ID: tailcfg.UserID(1)}
+	remoteIPWithAllCapabilities := "100.100.100.101"
+	remoteIPWithNoCapabilities := "100.100.100.102"
+
 	lal := memnet.Listen("local-tailscaled.sock:80")
 	defer lal.Close()
-	// Serve dummy localapi. Just returns "success".
-	localapi := &http.Server{Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		fmt.Fprintf(w, "success")
-	})}
+	localapi := mockLocalAPI(t,
+		map[string]*apitype.WhoIsResponse{
+			remoteIPWithAllCapabilities: {
+				Node:        &tailcfg.Node{StableID: "node1"},
+				UserProfile: remoteUser,
+				CapMap:      tailcfg.PeerCapMap{tailcfg.PeerCapabilityWebUI: []tailcfg.RawMessage{"{\"canEdit\":[\"*\"]}"}},
+			},
+			remoteIPWithNoCapabilities: {
+				Node:        &tailcfg.Node{StableID: "node2"},
+				UserProfile: remoteUser,
+			},
+		},
+		func() *ipnstate.PeerStatus { return self },
+		func() *ipn.Prefs { return prefs },
+		nil,
+	)
 	defer localapi.Close()
-
 	go localapi.Serve(lal)
-	s := &Server{lc: &tailscale.LocalClient{Dial: lal.Dial}}
+
+	s := &Server{
+		mode:    ManageServerMode,
+		lc:      &tailscale.LocalClient{Dial: lal.Dial},
+		timeNow: time.Now,
+	}
+
+	type requestTest struct {
+		remoteIP     string
+		wantResponse string
+		wantStatus   int
+	}
 
 	tests := []struct {
-		name           string
-		reqMethod      string
 		reqPath        string
+		reqMethod      string
 		reqContentType string
-		wantResp       string
-		wantStatus     int
+		reqBody        string
+		tests          []requestTest
 	}{{
-		name:       "invalid_endpoint",
-		reqMethod:  httpm.POST,
-		reqPath:    "/not-an-endpoint",
-		wantResp:   "invalid endpoint",
-		wantStatus: http.StatusNotFound,
+		reqPath:   "/not-an-endpoint",
+		reqMethod: httpm.POST,
+		tests: []requestTest{{
+			remoteIP:     remoteIPWithNoCapabilities,
+			wantResponse: "invalid endpoint",
+			wantStatus:   http.StatusNotFound,
+		}, {
+			remoteIP:     remoteIPWithAllCapabilities,
+			wantResponse: "invalid endpoint",
+			wantStatus:   http.StatusNotFound,
+		}},
 	}, {
-		name:       "not_in_localapi_allowlist",
-		reqMethod:  httpm.POST,
-		reqPath:    "/local/v0/not-allowlisted",
-		wantResp:   "/v0/not-allowlisted not allowed from localapi proxy",
-		wantStatus: http.StatusForbidden,
+		reqPath:   "/local/v0/not-an-endpoint",
+		reqMethod: httpm.POST,
+		tests: []requestTest{{
+			remoteIP:     remoteIPWithNoCapabilities,
+			wantResponse: "invalid endpoint",
+			wantStatus:   http.StatusNotFound,
+		}, {
+			remoteIP:     remoteIPWithAllCapabilities,
+			wantResponse: "invalid endpoint",
+			wantStatus:   http.StatusNotFound,
+		}},
 	}, {
-		name:       "in_localapi_allowlist",
-		reqMethod:  httpm.POST,
-		reqPath:    "/local/v0/logout",
-		wantResp:   "success", // Successfully allowed to hit localapi.
-		wantStatus: http.StatusOK,
+		reqPath:   "/local/v0/logout",
+		reqMethod: httpm.POST,
+		tests: []requestTest{{
+			remoteIP:     remoteIPWithNoCapabilities,
+			wantResponse: "not allowed", // requesting node has insufficient permissions
+			wantStatus:   http.StatusUnauthorized,
+		}, {
+			remoteIP:     remoteIPWithAllCapabilities,
+			wantResponse: "success", // requesting node has sufficient permissions
+			wantStatus:   http.StatusOK,
+		}},
+	}, {
+		reqPath:   "/exit-nodes",
+		reqMethod: httpm.GET,
+		tests: []requestTest{{
+			remoteIP:     remoteIPWithNoCapabilities,
+			wantResponse: "null",
+			wantStatus:   http.StatusOK, // allowed, no additional capabilities required
+		}, {
+			remoteIP:     remoteIPWithAllCapabilities,
+			wantResponse: "null",
+			wantStatus:   http.StatusOK,
+		}},
+	}, {
+		reqPath:   "/routes",
+		reqMethod: httpm.POST,
+		reqBody:   "{\"setExitNode\":true}",
+		tests: []requestTest{{
+			remoteIP:     remoteIPWithNoCapabilities,
+			wantResponse: "not allowed",
+			wantStatus:   http.StatusUnauthorized,
+		}, {
+			remoteIP:   remoteIPWithAllCapabilities,
+			wantStatus: http.StatusOK,
+		}},
 	}, {
-		name:           "patch_bad_contenttype",
-		reqMethod:      httpm.PATCH,
 		reqPath:        "/local/v0/prefs",
+		reqMethod:      httpm.PATCH,
+		reqBody:        "{\"runSSHSet\":true}",
+		reqContentType: "application/json",
+		tests: []requestTest{{
+			remoteIP:     remoteIPWithNoCapabilities,
+			wantResponse: "not allowed",
+			wantStatus:   http.StatusUnauthorized,
+		}, {
+			remoteIP:   remoteIPWithAllCapabilities,
+			wantStatus: http.StatusOK,
+		}},
+	}, {
+		reqPath:        "/local/v0/prefs",
+		reqMethod:      httpm.PATCH,
 		reqContentType: "multipart/form-data",
-		wantResp:       "invalid request",
-		wantStatus:     http.StatusBadRequest,
+		tests: []requestTest{{
+			remoteIP:     remoteIPWithNoCapabilities,
+			wantResponse: "invalid request",
+			wantStatus:   http.StatusBadRequest,
+		}, {
+			remoteIP:     remoteIPWithAllCapabilities,
+			wantResponse: "invalid request",
+			wantStatus:   http.StatusBadRequest,
+		}},
 	}}
 	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			r := httptest.NewRequest(tt.reqMethod, "/api"+tt.reqPath, nil)
-			if tt.reqContentType != "" {
-				r.Header.Add("Content-Type", tt.reqContentType)
-			}
-			w := httptest.NewRecorder()
+		for _, req := range tt.tests {
+			t.Run(req.remoteIP+"_requesting_"+tt.reqPath, func(t *testing.T) {
+				var reqBody io.Reader
+				if tt.reqBody != "" {
+					reqBody = bytes.NewBuffer([]byte(tt.reqBody))
+				}
+				r := httptest.NewRequest(tt.reqMethod, "/api"+tt.reqPath, reqBody)
+				r.RemoteAddr = req.remoteIP
+				if tt.reqContentType != "" {
+					r.Header.Add("Content-Type", tt.reqContentType)
+				}
+				w := httptest.NewRecorder()
 
-			s.serveAPI(w, r)
-			res := w.Result()
-			defer res.Body.Close()
-			if gotStatus := res.StatusCode; tt.wantStatus != gotStatus {
-				t.Errorf("wrong status; want=%v, got=%v", tt.wantStatus, gotStatus)
-			}
-			body, err := io.ReadAll(res.Body)
-			if err != nil {
-				t.Fatal(err)
-			}
-			gotResp := strings.TrimSuffix(string(body), "\n") // trim trailing newline
-			if tt.wantResp != gotResp {
-				t.Errorf("wrong response; want=%q, got=%q", tt.wantResp, gotResp)
-			}
-		})
+				s.serveAPI(w, r)
+				res := w.Result()
+				defer res.Body.Close()
+				if gotStatus := res.StatusCode; req.wantStatus != gotStatus {
+					t.Errorf("wrong status; want=%v, got=%v", req.wantStatus, gotStatus)
+				}
+				body, err := io.ReadAll(res.Body)
+				if err != nil {
+					t.Fatal(err)
+				}
+				gotResp := strings.TrimSuffix(string(body), "\n") // trim trailing newline
+				if req.wantResponse != gotResp {
+					t.Errorf("wrong response; want=%q, got=%q", req.wantResponse, gotResp)
+				}
+			})
+		}
 	}
 }
 
@@ -450,7 +548,7 @@ func TestServeAuth(t *testing.T) {
 		NodeName:      remoteNode.Node.Name,
 		NodeIP:        remoteIP,
 		ProfilePicURL: user.ProfilePicURL,
-		Capabilities:  peerCapabilities{},
+		Capabilities:  peerCapabilities{capFeatureAll: true},
 	}
 
 	testControlURL := &defaultControlURL
@@ -524,7 +622,7 @@ func TestServeAuth(t *testing.T) {
 			name:          "no-session",
 			path:          "/api/auth",
 			wantStatus:    http.StatusOK,
-			wantResp:      &authResponse{AuthNeeded: tailscaleAuth, ViewerIdentity: vi, ServerMode: ManageServerMode},
+			wantResp:      &authResponse{ViewerIdentity: vi, ServerMode: ManageServerMode},
 			wantNewCookie: false,
 			wantSession:   nil,
 		},
@@ -549,7 +647,7 @@ func TestServeAuth(t *testing.T) {
 			path:       "/api/auth",
 			cookie:     successCookie,
 			wantStatus: http.StatusOK,
-			wantResp:   &authResponse{AuthNeeded: tailscaleAuth, ViewerIdentity: vi, ServerMode: ManageServerMode},
+			wantResp:   &authResponse{ViewerIdentity: vi, ServerMode: ManageServerMode},
 			wantSession: &browserSession{
 				ID:            successCookie,
 				SrcNode:       remoteNode.Node.ID,
@@ -597,7 +695,7 @@ func TestServeAuth(t *testing.T) {
 			path:       "/api/auth",
 			cookie:     successCookie,
 			wantStatus: http.StatusOK,
-			wantResp:   &authResponse{CanManageNode: true, ViewerIdentity: vi, ServerMode: ManageServerMode},
+			wantResp:   &authResponse{Authorized: true, ViewerIdentity: vi, ServerMode: ManageServerMode},
 			wantSession: &browserSession{
 				ID:            successCookie,
 				SrcNode:       remoteNode.Node.ID,
@@ -1099,20 +1197,56 @@ func TestRequireTailscaleIP(t *testing.T) {
 }
 
 func TestPeerCapabilities(t *testing.T) {
+	userOwnedStatus := &ipnstate.Status{Self: &ipnstate.PeerStatus{UserID: tailcfg.UserID(1)}}
+	tags := views.SliceOf[string]([]string{"tag:server"})
+	tagOwnedStatus := &ipnstate.Status{Self: &ipnstate.PeerStatus{Tags: &tags}}
+
 	// Testing web.toPeerCapabilities
 	toPeerCapsTests := []struct {
 		name     string
+		status   *ipnstate.Status
 		whois    *apitype.WhoIsResponse
 		wantCaps peerCapabilities
 	}{
 		{
 			name:     "empty-whois",
+			status:   userOwnedStatus,
 			whois:    nil,
 			wantCaps: peerCapabilities{},
 		},
 		{
-			name: "no-webui-caps",
+			name:   "user-owned-node-non-owner-caps-ignored",
+			status: userOwnedStatus,
 			whois: &apitype.WhoIsResponse{
+				UserProfile: &tailcfg.UserProfile{ID: tailcfg.UserID(2)},
+				Node:        &tailcfg.Node{ID: tailcfg.NodeID(1)},
+				CapMap: tailcfg.PeerCapMap{
+					tailcfg.PeerCapabilityWebUI: []tailcfg.RawMessage{
+						"{\"canEdit\":[\"ssh\",\"subnets\"]}",
+					},
+				},
+			},
+			wantCaps: peerCapabilities{},
+		},
+		{
+			name:   "user-owned-node-owner-caps-ignored",
+			status: userOwnedStatus,
+			whois: &apitype.WhoIsResponse{
+				UserProfile: &tailcfg.UserProfile{ID: tailcfg.UserID(1)},
+				Node:        &tailcfg.Node{ID: tailcfg.NodeID(1)},
+				CapMap: tailcfg.PeerCapMap{
+					tailcfg.PeerCapabilityWebUI: []tailcfg.RawMessage{
+						"{\"canEdit\":[\"ssh\",\"subnets\"]}",
+					},
+				},
+			},
+			wantCaps: peerCapabilities{capFeatureAll: true}, // should just have wildcard
+		},
+		{
+			name:   "tag-owned-no-webui-caps",
+			status: tagOwnedStatus,
+			whois: &apitype.WhoIsResponse{
+				Node: &tailcfg.Node{ID: tailcfg.NodeID(1)},
 				CapMap: tailcfg.PeerCapMap{
 					tailcfg.PeerCapabilityDebugPeer: []tailcfg.RawMessage{},
 				},
@@ -1120,66 +1254,74 @@ func TestPeerCapabilities(t *testing.T) {
 			wantCaps: peerCapabilities{},
 		},
 		{
-			name: "one-webui-cap",
+			name:   "tag-owned-one-webui-cap",
+			status: tagOwnedStatus,
 			whois: &apitype.WhoIsResponse{
+				Node: &tailcfg.Node{ID: tailcfg.NodeID(1)},
 				CapMap: tailcfg.PeerCapMap{
 					tailcfg.PeerCapabilityWebUI: []tailcfg.RawMessage{
-						"{\"canEdit\":[\"ssh\",\"subnet\"]}",
+						"{\"canEdit\":[\"ssh\",\"subnets\"]}",
 					},
 				},
 			},
 			wantCaps: peerCapabilities{
-				capFeatureSSH:    true,
-				capFeatureSubnet: true,
+				capFeatureSSH:     true,
+				capFeatureSubnets: true,
 			},
 		},
 		{
-			name: "multiple-webui-cap",
+			name:   "tag-owned-multiple-webui-cap",
+			status: tagOwnedStatus,
 			whois: &apitype.WhoIsResponse{
+				Node: &tailcfg.Node{ID: tailcfg.NodeID(1)},
 				CapMap: tailcfg.PeerCapMap{
 					tailcfg.PeerCapabilityWebUI: []tailcfg.RawMessage{
-						"{\"canEdit\":[\"ssh\",\"subnet\"]}",
-						"{\"canEdit\":[\"subnet\",\"exitnode\",\"*\"]}",
+						"{\"canEdit\":[\"ssh\",\"subnets\"]}",
+						"{\"canEdit\":[\"subnets\",\"exitnodes\",\"*\"]}",
 					},
 				},
 			},
 			wantCaps: peerCapabilities{
-				capFeatureSSH:      true,
-				capFeatureSubnet:   true,
-				capFeatureExitNode: true,
-				capFeatureAll:      true,
+				capFeatureSSH:       true,
+				capFeatureSubnets:   true,
+				capFeatureExitNodes: true,
+				capFeatureAll:       true,
 			},
 		},
 		{
-			name: "case=insensitive-caps",
+			name:   "tag-owned-case-insensitive-caps",
+			status: tagOwnedStatus,
 			whois: &apitype.WhoIsResponse{
+				Node: &tailcfg.Node{ID: tailcfg.NodeID(1)},
 				CapMap: tailcfg.PeerCapMap{
 					tailcfg.PeerCapabilityWebUI: []tailcfg.RawMessage{
-						"{\"canEdit\":[\"SSH\",\"sUBnet\"]}",
+						"{\"canEdit\":[\"SSH\",\"sUBnets\"]}",
 					},
 				},
 			},
 			wantCaps: peerCapabilities{
-				capFeatureSSH:    true,
-				capFeatureSubnet: true,
+				capFeatureSSH:     true,
+				capFeatureSubnets: true,
 			},
 		},
 		{
-			name: "random-canEdit-contents-dont-error",
+			name:   "tag-owned-random-canEdit-contents-get-dropped",
+			status: tagOwnedStatus,
 			whois: &apitype.WhoIsResponse{
+				Node: &tailcfg.Node{ID: tailcfg.NodeID(1)},
 				CapMap: tailcfg.PeerCapMap{
 					tailcfg.PeerCapabilityWebUI: []tailcfg.RawMessage{
 						"{\"canEdit\":[\"unknown-feature\"]}",
 					},
 				},
 			},
-			wantCaps: peerCapabilities{
-				"unknown-feature": true,
-			},
+			wantCaps: peerCapabilities{},
 		},
 		{
-			name: "no-canEdit-section",
+			name:   "tag-owned-no-canEdit-section",
+			status: tagOwnedStatus,
 			whois: &apitype.WhoIsResponse{
+				Node: &tailcfg.Node{ID: tailcfg.NodeID(1)},
 				CapMap: tailcfg.PeerCapMap{
 					tailcfg.PeerCapabilityWebUI: []tailcfg.RawMessage{
 						"{\"canDoSomething\":[\"*\"]}",
@@ -1188,10 +1330,23 @@ func TestPeerCapabilities(t *testing.T) {
 			},
 			wantCaps: peerCapabilities{},
 		},
+		{
+			name:   "tagged-source-caps-ignored",
+			status: tagOwnedStatus,
+			whois: &apitype.WhoIsResponse{
+				Node: &tailcfg.Node{ID: tailcfg.NodeID(1), Tags: tags.AsSlice()},
+				CapMap: tailcfg.PeerCapMap{
+					tailcfg.PeerCapabilityWebUI: []tailcfg.RawMessage{
+						"{\"canEdit\":[\"ssh\",\"subnets\"]}",
+					},
+				},
+			},
+			wantCaps: peerCapabilities{},
+		},
 	}
 	for _, tt := range toPeerCapsTests {
 		t.Run("toPeerCapabilities-"+tt.name, func(t *testing.T) {
-			got, err := toPeerCapabilities(tt.whois)
+			got, err := toPeerCapabilities(tt.status, tt.whois)
 			if err != nil {
 				t.Fatalf("unexpected: %v", err)
 			}
@@ -1211,36 +1366,33 @@ func TestPeerCapabilities(t *testing.T) {
 			name: "empty-caps",
 			caps: nil,
 			wantCanEdit: map[capFeature]bool{
-				capFeatureAll:      false,
-				capFeatureFunnel:   false,
-				capFeatureSSH:      false,
-				capFeatureSubnet:   false,
-				capFeatureExitNode: false,
-				capFeatureAccount:  false,
+				capFeatureAll:       false,
+				capFeatureSSH:       false,
+				capFeatureSubnets:   false,
+				capFeatureExitNodes: false,
+				capFeatureAccount:   false,
 			},
 		},
 		{
 			name: "some-caps",
 			caps: peerCapabilities{capFeatureSSH: true, capFeatureAccount: true},
 			wantCanEdit: map[capFeature]bool{
-				capFeatureAll:      false,
-				capFeatureFunnel:   false,
-				capFeatureSSH:      true,
-				capFeatureSubnet:   false,
-				capFeatureExitNode: false,
-				capFeatureAccount:  true,
+				capFeatureAll:       false,
+				capFeatureSSH:       true,
+				capFeatureSubnets:   false,
+				capFeatureExitNodes: false,
+				capFeatureAccount:   true,
 			},
 		},
 		{
 			name: "wildcard-in-caps",
 			caps: peerCapabilities{capFeatureAll: true, capFeatureAccount: true},
 			wantCanEdit: map[capFeature]bool{
-				capFeatureAll:      true,
-				capFeatureFunnel:   true,
-				capFeatureSSH:      true,
-				capFeatureSubnet:   true,
-				capFeatureExitNode: true,
-				capFeatureAccount:  true,
+				capFeatureAll:       true,
+				capFeatureSSH:       true,
+				capFeatureSubnets:   true,
+				capFeatureExitNodes: true,
+				capFeatureAccount:   true,
 			},
 		},
 	}
@@ -1301,6 +1453,9 @@ func mockLocalAPI(t *testing.T, whoIs map[string]*apitype.WhoIsResponse, self fu
 			metricCapture(metricNames[0].Name)
 			writeJSON(w, struct{}{})
 			return
+		case "/localapi/v0/logout":
+			fmt.Fprintf(w, "success")
+			return
 		default:
 			t.Fatalf("unhandled localapi test endpoint %q, add to localapi handler func in test", r.URL.Path)
 		}

clientupdate/clientupdate.go

@@ -29,6 +29,7 @@ import (
 
 	"github.com/google/uuid"
 	"tailscale.com/clientupdate/distsign"
+	"tailscale.com/hostinfo"
 	"tailscale.com/types/logger"
 	"tailscale.com/util/cmpver"
 	"tailscale.com/util/winutil"
@@ -162,11 +163,16 @@ func NewUpdater(args Arguments) (*Updater, error) {
 type updateFunction func() error
 
 func (up *Updater) getUpdateFunction() (fn updateFunction, canAutoUpdate bool) {
+	canAutoUpdate = !hostinfo.New().Container.EqualBool(true) // EqualBool(false) would return false if the value is not set.
 	switch runtime.GOOS {
 	case "windows":
-		return up.updateWindows, true
+		return up.updateWindows, canAutoUpdate
 	case "linux":
 		switch distro.Get() {
+		case distro.NixOS:
+			// NixOS packages are immutable and managed with a system-wide
+			// configuration.
+			return up.updateNixos, false
 		case distro.Synology:
 			// Synology updates use our own pkgs.tailscale.com instead of the
 			// Synology Package Center. We should eventually get to a regular
@@ -174,20 +180,20 @@ func (up *Updater) getUpdateFunction() (fn updateFunction, canAutoUpdate bool) {
 			// auto-update mechanism.
 			return up.updateSynology, false
 		case distro.Debian: // includes Ubuntu
-			return up.updateDebLike, true
+			return up.updateDebLike, canAutoUpdate
 		case distro.Arch:
 			if up.archPackageInstalled() {
 				// Arch update func just prints a message about how to update,
 				// it doesn't support auto-updates.
 				return up.updateArchLike, false
 			}
-			return up.updateLinuxBinary, true
+			return up.updateLinuxBinary, canAutoUpdate
 		case distro.Alpine:
-			return up.updateAlpineLike, true
+			return up.updateAlpineLike, canAutoUpdate
 		case distro.Unraid:
-			return up.updateUnraid, true
+			return up.updateUnraid, canAutoUpdate
 		case distro.QNAP:
-			return up.updateQNAP, true
+			return up.updateQNAP, canAutoUpdate
 		}
 		switch {
 		case haveExecutable("pacman"):
@@ -196,21 +202,21 @@ func (up *Updater) getUpdateFunction() (fn updateFunction, canAutoUpdate bool) {
 				// it doesn't support auto-updates.
 				return up.updateArchLike, false
 			}
-			return up.updateLinuxBinary, true
+			return up.updateLinuxBinary, canAutoUpdate
 		case haveExecutable("apt-get"): // TODO(awly): add support for "apt"
 			// The distro.Debian switch case above should catch most apt-based
 			// systems, but add this fallback just in case.
-			return up.updateDebLike, true
+			return up.updateDebLike, canAutoUpdate
 		case haveExecutable("dnf"):
-			return up.updateFedoraLike("dnf"), true
+			return up.updateFedoraLike("dnf"), canAutoUpdate
 		case haveExecutable("yum"):
-			return up.updateFedoraLike("yum"), true
+			return up.updateFedoraLike("yum"), canAutoUpdate
 		case haveExecutable("apk"):
-			return up.updateAlpineLike, true
+			return up.updateAlpineLike, canAutoUpdate
 		}
 		// If nothing matched, fall back to tarball updates.
 		if up.Update == nil {
-			return up.updateLinuxBinary, true
+			return up.updateLinuxBinary, canAutoUpdate
 		}
 	case "darwin":
 		switch {
@@ -226,7 +232,7 @@ func (up *Updater) getUpdateFunction() (fn updateFunction, canAutoUpdate bool) {
 			return nil, false
 		}
 	case "freebsd":
-		return up.updateFreeBSD, true
+		return up.updateFreeBSD, canAutoUpdate
 	}
 	return nil, false
 }
@@ -432,7 +438,7 @@ func (up *Updater) updateDebLike() error {
 		return fmt.Errorf("apt-get update failed: %w; output:\n%s", err, out)
 	}
 
-	for i := 0; i < 2; i++ {
+	for range 2 {
 		out, err := exec.Command("apt-get", "install", "--yes", "--allow-downgrades", "tailscale="+ver).CombinedOutput()
 		if err != nil {
 			if !bytes.Contains(out, []byte(`dpkg was interrupted`)) {
@@ -522,6 +528,13 @@ func (up *Updater) updateArchLike() error {
 you can use "pacman --sync --refresh --sysupgrade" or "pacman -Syu" to upgrade the system, including Tailscale.`)
 }
 
+func (up *Updater) updateNixos() error {
+	// NixOS package updates are managed on a system level and not individually.
+	// Direct users to update their nix channel or nixpkgs flake input to
+	// receive the latest version.
+	return errors.New(`individual package updates are not supported on NixOS installations. Update your system channel or flake inputs to get the latest Tailscale version from nixpkgs.`)
+}
+
 const yumRepoConfigFile = "/etc/yum.repos.d/tailscale.repo"
 
 // updateFedoraLike updates tailscale on any distros in the Fedora family,
@@ -654,6 +667,7 @@ func (up *Updater) updateAlpineLike() (err error) {
 
 func parseAlpinePackageVersion(out []byte) (string, error) {
 	s := bufio.NewScanner(bytes.NewReader(out))
+	var maxVer string
 	for s.Scan() {
 		// The line should look like this:
 		// tailscale-1.44.2-r0 description:
@@ -665,7 +679,13 @@ func parseAlpinePackageVersion(out []byte) (string, error) {
 		if len(parts) < 3 {
 			return "", fmt.Errorf("malformed info line: %q", line)
 		}
-		return parts[1], nil
+		ver := parts[1]
+		if cmpver.Compare(ver, maxVer) == 1 {
+			maxVer = ver
+		}
+	}
+	if maxVer != "" {
+		return maxVer, nil
 	}
 	return "", errors.New("tailscale version not found in output")
 }
@@ -818,7 +838,7 @@ func (up *Updater) switchOutputToFile() (io.Closer, error) {
 func (up *Updater) installMSI(msi string) error {
 	var err error
 	for tries := 0; tries < 2; tries++ {
-		cmd := exec.Command("msiexec.exe", "/i", filepath.Base(msi), "/quiet", "/promptrestart", "/qn")
+		cmd := exec.Command("msiexec.exe", "/i", filepath.Base(msi), "/quiet", "/norestart", "/qn")
 		cmd.Dir = filepath.Dir(msi)
 		cmd.Stdout = up.Stdout
 		cmd.Stderr = up.Stderr
@@ -999,6 +1019,20 @@ func (up *Updater) updateLinuxBinary() error {
 	return nil
 }
 
+func restartSystemdUnit(ctx context.Context) error {
+	if _, err := exec.LookPath("systemctl"); err != nil {
+		// Likely not a systemd-managed distro.
+		return errors.ErrUnsupported
+	}
+	if out, err := exec.Command("systemctl", "daemon-reload").CombinedOutput(); err != nil {
+		return fmt.Errorf("systemctl daemon-reload failed: %w\noutput: %s", err, out)
+	}
+	if out, err := exec.Command("systemctl", "restart", "tailscaled.service").CombinedOutput(); err != nil {
+		return fmt.Errorf("systemctl restart failed: %w\noutput: %s", err, out)
+	}
+	return nil
+}
+
 func (up *Updater) downloadLinuxTarball(ver string) (string, error) {
 	dlDir, err := os.UserCacheDir()
 	if err != nil {
@@ -1277,10 +1311,23 @@ func LatestTailscaleVersion(track string) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	if latest.Version == "" {
-		return "", fmt.Errorf("no latest version found for %q track", track)
+	ver := latest.Version
+	switch runtime.GOOS {
+	case "windows":
+		ver = latest.MSIsVersion
+	case "darwin":
+		ver = latest.MacZipsVersion
+	case "linux":
+		ver = latest.TarballsVersion
+		if distro.Get() == distro.Synology {
+			ver = latest.SPKsVersion
+		}
 	}
-	return latest.Version, nil
+
+	if ver == "" {
+		return "", fmt.Errorf("no latest version found for OS %q on %q track", runtime.GOOS, track)
+	}
+	return ver, nil
 }
 
 type trackPackages struct {

clientupdate/clientupdate_test.go

@@ -251,6 +251,29 @@ tailscale installed size:
 			out:     "",
 			wantErr: true,
 		},
+		{
+			desc: "multiple versions",
+			out: `
+tailscale-1.54.1-r0 description:
+The easiest, most secure way to use WireGuard and 2FA
+
+tailscale-1.54.1-r0 webpage:
+https://tailscale.com/
+
+tailscale-1.54.1-r0 installed size:
+34 MiB
+
+tailscale-1.58.2-r0 description:
+The easiest, most secure way to use WireGuard and 2FA
+
+tailscale-1.58.2-r0 webpage:
+https://tailscale.com/
+
+tailscale-1.58.2-r0 installed size:
+35 MiB
+`,
+			want: "1.58.2",
+		},
 	}
 
 	for _, tt := range tests {
@@ -640,7 +663,7 @@ func genTarball(t *testing.T, path string, files map[string]string) {
 
 func TestWriteFileOverwrite(t *testing.T) {
 	path := filepath.Join(t.TempDir(), "test")
-	for i := 0; i < 2; i++ {
+	for i := range 2 {
 		content := fmt.Sprintf("content %d", i)
 		if err := writeFile(strings.NewReader(content), path, 0600); err != nil {
 			t.Fatal(err)

clientupdate/distsign/distsign_test.go

@@ -445,7 +445,7 @@ type testServer struct {
 
 func newTestServer(t *testing.T) *testServer {
 	var roots []rootKeyPair
-	for i := 0; i < 3; i++ {
+	for range 3 {
 		roots = append(roots, newRootKeyPair(t))
 	}
 

clientupdate/systemd_linux.go

@@ -1,37 +0,0 @@
-// Copyright (c) Tailscale Inc & AUTHORS
-// SPDX-License-Identifier: BSD-3-Clause
-
-package clientupdate
-
-import (
-	"context"
-	"errors"
-	"fmt"
-
-	"github.com/coreos/go-systemd/v22/dbus"
-)
-
-func restartSystemdUnit(ctx context.Context) error {
-	c, err := dbus.NewWithContext(ctx)
-	if err != nil {
-		// Likely not a systemd-managed distro.
-		return errors.ErrUnsupported
-	}
-	defer c.Close()
-	if err := c.ReloadContext(ctx); err != nil {
-		return fmt.Errorf("failed to reload tailsacled.service: %w", err)
-	}
-	ch := make(chan string, 1)
-	if _, err := c.RestartUnitContext(ctx, "tailscaled.service", "replace", ch); err != nil {
-		return fmt.Errorf("failed to restart tailsacled.service: %w", err)
-	}
-	select {
-	case res := <-ch:
-		if res != "done" {
-			return fmt.Errorf("systemd service restart failed with result %q", res)
-		}
-	case <-ctx.Done():
-		return ctx.Err()
-	}
-	return nil
-}

clientupdate/systemd_other.go

@@ -1,15 +0,0 @@
-// Copyright (c) Tailscale Inc & AUTHORS
-// SPDX-License-Identifier: BSD-3-Clause
-
-//go:build !linux
-
-package clientupdate
-
-import (
-	"context"
-	"errors"
-)
-
-func restartSystemdUnit(ctx context.Context) error {
-	return errors.ErrUnsupported
-}

cmd/cloner/cloner.go

@@ -102,7 +102,7 @@ func gen(buf *bytes.Buffer, it *codegen.ImportTracker, typ *types.Named) {
 	writef("}")
 	writef("dst := new(%s)", name)
 	writef("*dst = *src")
-	for i := 0; i < t.NumFields(); i++ {
+	for i := range t.NumFields() {
 		fname := t.Field(i).Name()
 		ft := t.Field(i).Type()
 		if !codegen.ContainsPointers(ft) || codegen.HasNoClone(t.Tag(i)) {

cmd/containerboot/kube.go

@@ -8,6 +8,7 @@ package main
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"log"
 	"net/http"
@@ -18,20 +19,6 @@ import (
 	"tailscale.com/tailcfg"
 )
 
-// findKeyInKubeSecret inspects the kube secret secretName for a data
-// field called "authkey", and returns its value if present.
-func findKeyInKubeSecret(ctx context.Context, secretName string) (string, error) {
-	s, err := kc.GetSecret(ctx, secretName)
-	if err != nil {
-		return "", err
-	}
-	ak, ok := s.Data["authkey"]
-	if !ok {
-		return "", nil
-	}
-	return string(ak), nil
-}
-
 // storeDeviceInfo writes deviceID into the "device_id" data field of the kube
 // secret secretName.
 func storeDeviceInfo(ctx context.Context, secretName string, deviceID tailcfg.StableNodeID, fqdn string, addresses []netip.Prefix) error {
@@ -88,9 +75,59 @@ func deleteAuthKey(ctx context.Context, secretName string) error {
 	return nil
 }
 
-var kc *kube.Client
+var kc kube.Client
 
-func initKube(root string) {
+// setupKube is responsible for doing any necessary configuration and checks to
+// ensure that tailscale state storage and authentication mechanism will work on
+// Kubernetes.
+func (cfg *settings) setupKube(ctx context.Context) error {
+	if cfg.KubeSecret == "" {
+		return nil
+	}
+	canPatch, canCreate, err := kc.CheckSecretPermissions(ctx, cfg.KubeSecret)
+	if err != nil {
+		return fmt.Errorf("Some Kubernetes permissions are missing, please check your RBAC configuration: %v", err)
+	}
+	cfg.KubernetesCanPatch = canPatch
+
+	s, err := kc.GetSecret(ctx, cfg.KubeSecret)
+	if err != nil && kube.IsNotFoundErr(err) && !canCreate {
+		return fmt.Errorf("Tailscale state Secret %s does not exist and we don't have permissions to create it. "+
+			"If you intend to store tailscale state elsewhere than a Kubernetes Secret, "+
+			"you can explicitly set TS_KUBE_SECRET env var to an empty string. "+
+			"Else ensure that RBAC is set up that allows the service account associated with this installation to create Secrets.", cfg.KubeSecret)
+	} else if err != nil && !kube.IsNotFoundErr(err) {
+		return fmt.Errorf("Getting Tailscale state Secret %s: %v", cfg.KubeSecret, err)
+	}
+
+	if cfg.AuthKey == "" && !isOneStepConfig(cfg) {
+		if s == nil {
+			log.Print("TS_AUTHKEY not provided and kube secret does not exist, login will be interactive if needed.")
+			return nil
+		}
+		keyBytes, _ := s.Data["authkey"]
+		key := string(keyBytes)
+
+		if key != "" {
+			// This behavior of pulling authkeys from kube secrets was added
+			// at the same time as the patch permission, so we can enforce
+			// that we must be able to patch out the authkey after
+			// authenticating if you want to use this feature. This avoids
+			// us having to deal with the case where we might leave behind
+			// an unnecessary reusable authkey in a secret, like a rake in
+			// the grass.
+			if !cfg.KubernetesCanPatch {
+				return errors.New("authkey found in TS_KUBE_SECRET, but the pod doesn't have patch permissions on the secret to manage the authkey.")
+			}
+			cfg.AuthKey = key
+		} else {
+			log.Print("No authkey found in kube secret and TS_AUTHKEY not provided, login will be interactive if needed.")
+		}
+	}
+	return nil
+}
+
+func initKubeClient(root string) {
 	if root != "/" {
 		// If we are running in a test, we need to set the root path to the fake
 		// service account directory.

cmd/containerboot/kube_test.go

@@ -0,0 +1,206 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build linux
+
+package main
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"tailscale.com/kube"
+)
+
+func TestSetupKube(t *testing.T) {
+	tests := []struct {
+		name    string
+		cfg     *settings
+		wantErr bool
+		wantCfg *settings
+		kc      kube.Client
+	}{
+		{
+			name: "TS_AUTHKEY set, state Secret exists",
+			cfg: &settings{
+				AuthKey:    "foo",
+				KubeSecret: "foo",
+			},
+			kc: &kube.FakeClient{
+				CheckSecretPermissionsImpl: func(context.Context, string) (bool, bool, error) {
+					return false, false, nil
+				},
+				GetSecretImpl: func(context.Context, string) (*kube.Secret, error) {
+					return nil, nil
+				},
+			},
+			wantCfg: &settings{
+				AuthKey:    "foo",
+				KubeSecret: "foo",
+			},
+		},
+		{
+			name: "TS_AUTHKEY set, state Secret does not exist, we have permissions to create it",
+			cfg: &settings{
+				AuthKey:    "foo",
+				KubeSecret: "foo",
+			},
+			kc: &kube.FakeClient{
+				CheckSecretPermissionsImpl: func(context.Context, string) (bool, bool, error) {
+					return false, true, nil
+				},
+				GetSecretImpl: func(context.Context, string) (*kube.Secret, error) {
+					return nil, &kube.Status{Code: 404}
+				},
+			},
+			wantCfg: &settings{
+				AuthKey:    "foo",
+				KubeSecret: "foo",
+			},
+		},
+		{
+			name: "TS_AUTHKEY set, state Secret does not exist, we do not have permissions to create it",
+			cfg: &settings{
+				AuthKey:    "foo",
+				KubeSecret: "foo",
+			},
+			kc: &kube.FakeClient{
+				CheckSecretPermissionsImpl: func(context.Context, string) (bool, bool, error) {
+					return false, false, nil
+				},
+				GetSecretImpl: func(context.Context, string) (*kube.Secret, error) {
+					return nil, &kube.Status{Code: 404}
+				},
+			},
+			wantCfg: &settings{
+				AuthKey:    "foo",
+				KubeSecret: "foo",
+			},
+			wantErr: true,
+		},
+		{
+			name: "TS_AUTHKEY set, we encounter a non-404 error when trying to retrieve the state Secret",
+			cfg: &settings{
+				AuthKey:    "foo",
+				KubeSecret: "foo",
+			},
+			kc: &kube.FakeClient{
+				CheckSecretPermissionsImpl: func(context.Context, string) (bool, bool, error) {
+					return false, false, nil
+				},
+				GetSecretImpl: func(context.Context, string) (*kube.Secret, error) {
+					return nil, &kube.Status{Code: 403}
+				},
+			},
+			wantCfg: &settings{
+				AuthKey:    "foo",
+				KubeSecret: "foo",
+			},
+			wantErr: true,
+		},
+		{
+			name: "TS_AUTHKEY set, we encounter a non-404 error when trying to check Secret permissions",
+			cfg: &settings{
+				AuthKey:    "foo",
+				KubeSecret: "foo",
+			},
+			wantCfg: &settings{
+				AuthKey:    "foo",
+				KubeSecret: "foo",
+			},
+			kc: &kube.FakeClient{
+				CheckSecretPermissionsImpl: func(context.Context, string) (bool, bool, error) {
+					return false, false, errors.New("broken")
+				},
+			},
+			wantErr: true,
+		},
+		{
+			// Interactive login using URL in Pod logs
+			name: "TS_AUTHKEY not set, state Secret does not exist, we have permissions to create it",
+			cfg: &settings{
+				KubeSecret: "foo",
+			},
+			wantCfg: &settings{
+				KubeSecret: "foo",
+			},
+			kc: &kube.FakeClient{
+				CheckSecretPermissionsImpl: func(context.Context, string) (bool, bool, error) {
+					return false, true, nil
+				},
+				GetSecretImpl: func(context.Context, string) (*kube.Secret, error) {
+					return nil, &kube.Status{Code: 404}
+				},
+			},
+		},
+		{
+			// Interactive login using URL in Pod logs
+			name: "TS_AUTHKEY not set, state Secret exists, but does not contain auth key",
+			cfg: &settings{
+				KubeSecret: "foo",
+			},
+			wantCfg: &settings{
+				KubeSecret: "foo",
+			},
+			kc: &kube.FakeClient{
+				CheckSecretPermissionsImpl: func(context.Context, string) (bool, bool, error) {
+					return false, false, nil
+				},
+				GetSecretImpl: func(context.Context, string) (*kube.Secret, error) {
+					return &kube.Secret{}, nil
+				},
+			},
+		},
+		{
+			name: "TS_AUTHKEY not set, state Secret contains auth key, we do not have RBAC to patch it",
+			cfg: &settings{
+				KubeSecret: "foo",
+			},
+			kc: &kube.FakeClient{
+				CheckSecretPermissionsImpl: func(context.Context, string) (bool, bool, error) {
+					return false, false, nil
+				},
+				GetSecretImpl: func(context.Context, string) (*kube.Secret, error) {
+					return &kube.Secret{Data: map[string][]byte{"authkey": []byte("foo")}}, nil
+				},
+			},
+			wantCfg: &settings{
+				KubeSecret: "foo",
+			},
+			wantErr: true,
+		},
+		{
+			name: "TS_AUTHKEY not set, state Secret contains auth key, we have RBAC to patch it",
+			cfg: &settings{
+				KubeSecret: "foo",
+			},
+			kc: &kube.FakeClient{
+				CheckSecretPermissionsImpl: func(context.Context, string) (bool, bool, error) {
+					return true, false, nil
+				},
+				GetSecretImpl: func(context.Context, string) (*kube.Secret, error) {
+					return &kube.Secret{Data: map[string][]byte{"authkey": []byte("foo")}}, nil
+				},
+			},
+			wantCfg: &settings{
+				KubeSecret:         "foo",
+				AuthKey:            "foo",
+				KubernetesCanPatch: true,
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		kc = tt.kc
+		t.Run(tt.name, func(t *testing.T) {
+			if err := tt.cfg.setupKube(context.Background()); (err != nil) != tt.wantErr {
+				t.Errorf("settings.setupKube() error = %v, wantErr %v", err, tt.wantErr)
+			}
+			if diff := cmp.Diff(*tt.cfg, *tt.wantCfg); diff != "" {
+				t.Errorf("unexpected contents of settings after running settings.setupKube()\n(-got +want):\n%s", diff)
+			}
+		})
+	}
+}

cmd/containerboot/main.go

@@ -18,7 +18,11 @@
 //     previously advertised routes. To accept routes, use TS_EXTRA_ARGS to pass
 //     in --accept-routes.
 //   - TS_DEST_IP: proxy all incoming Tailscale traffic to the given
-//     destination.
+//     destination defined by an IP address.
+//   - TS_EXPERIMENTAL_DEST_DNS_NAME: proxy all incoming Tailscale traffic to the given
+//     destination defined by a DNS name. The DNS name will be periodically resolved and firewall rules updated accordingly.
+//     This is currently intended to be used by the Kubernetes operator (ExternalName Services).
+//     This is an experimental env var and will likely change in the future.
 //   - TS_TAILNET_TARGET_IP: proxy all incoming non-Tailscale traffic to the given
 //     destination defined by an IP.
 //   - TS_TAILNET_TARGET_FQDN: proxy all incoming non-Tailscale traffic to the given
@@ -48,13 +52,24 @@
 //     ${TS_CERT_DOMAIN}, it will be replaced with the value of the available FQDN.
 //     It cannot be used in conjunction with TS_DEST_IP. The file is watched for changes,
 //     and will be re-applied when it changes.
-//   - EXPERIMENTAL_TS_CONFIGFILE_PATH: if specified, a path to tailscaled
-//     config. If this is set, TS_HOSTNAME, TS_EXTRA_ARGS, TS_AUTHKEY,
+//   - TS_EXPERIMENTAL_VERSIONED_CONFIG_DIR: if specified, a path to a
+//     directory that containers tailscaled config in file. The config file needs to be
+//     named cap-<current-tailscaled-cap>.hujson. If this is set, TS_HOSTNAME,
+//     TS_EXTRA_ARGS, TS_AUTHKEY,
 //     TS_ROUTES, TS_ACCEPT_DNS env vars must not be set. If this is set,
 //     containerboot only runs `tailscaled --config <path-to-this-configfile>`
 //     and not `tailscale up` or `tailscale set`.
 //     The config file contents are currently read once on container start.
 //     NB: This env var is currently experimental and the logic will likely change!
+//   - EXPERIMENTAL_ALLOW_PROXYING_CLUSTER_TRAFFIC_VIA_INGRESS: if set to true
+//     and if this containerboot instance is an L7 ingress proxy (created by
+//     the Kubernetes operator), set up rules to allow proxying cluster traffic,
+//     received on the Pod IP of this node, to the ingress target in the cluster.
+//     This, in conjunction with MagicDNS name resolution in cluster, can be
+//     useful for cases where a cluster workload needs to access a target in
+//     cluster using the same hostname (in this case, the MagicDNS name of the ingress proxy)
+//     as a non-cluster workload on tailnet.
+//     This is only meant to be configured by the Kubernetes operator.
 //
 // When running on Kubernetes, containerboot defaults to storing state in the
 // "tailscale" kube secret. To store state on local disk instead, set
@@ -73,12 +88,16 @@ import (
 	"fmt"
 	"io/fs"
 	"log"
+	"math"
+	"net"
 	"net/netip"
 	"os"
 	"os/exec"
 	"os/signal"
+	"path"
 	"path/filepath"
 	"reflect"
+	"slices"
 	"strconv"
 	"strings"
 	"sync"
@@ -91,6 +110,7 @@ import (
 	"tailscale.com/client/tailscale"
 	"tailscale.com/ipn"
 	"tailscale.com/ipn/conffile"
+	kubeutils "tailscale.com/k8s-operator"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/logger"
 	"tailscale.com/types/ptr"
@@ -108,29 +128,32 @@ func newNetfilterRunner(logf logger.Logf) (linuxfw.NetfilterRunner, error) {
 func main() {
 	log.SetPrefix("boot: ")
 	tailscale.I_Acknowledge_This_API_Is_Unstable = true
-
 	cfg := &settings{
-		AuthKey:                  defaultEnvs([]string{"TS_AUTHKEY", "TS_AUTH_KEY"}, ""),
-		Hostname:                 defaultEnv("TS_HOSTNAME", ""),
-		Routes:                   defaultEnvStringPointer("TS_ROUTES"),
-		ServeConfigPath:          defaultEnv("TS_SERVE_CONFIG", ""),
-		ProxyTo:                  defaultEnv("TS_DEST_IP", ""),
-		TailnetTargetIP:          defaultEnv("TS_TAILNET_TARGET_IP", ""),
-		TailnetTargetFQDN:        defaultEnv("TS_TAILNET_TARGET_FQDN", ""),
-		DaemonExtraArgs:          defaultEnv("TS_TAILSCALED_EXTRA_ARGS", ""),
-		ExtraArgs:                defaultEnv("TS_EXTRA_ARGS", ""),
-		InKubernetes:             os.Getenv("KUBERNETES_SERVICE_HOST") != "",
-		UserspaceMode:            defaultBool("TS_USERSPACE", true),
-		StateDir:                 defaultEnv("TS_STATE_DIR", ""),
-		AcceptDNS:                defaultEnvBoolPointer("TS_ACCEPT_DNS"),
-		KubeSecret:               defaultEnv("TS_KUBE_SECRET", "tailscale"),
-		SOCKSProxyAddr:           defaultEnv("TS_SOCKS5_SERVER", ""),
-		HTTPProxyAddr:            defaultEnv("TS_OUTBOUND_HTTP_PROXY_LISTEN", ""),
-		Socket:                   defaultEnv("TS_SOCKET", "/tmp/tailscaled.sock"),
-		AuthOnce:                 defaultBool("TS_AUTH_ONCE", false),
-		Root:                     defaultEnv("TS_TEST_ONLY_ROOT", "/"),
-		TailscaledConfigFilePath: defaultEnv("EXPERIMENTAL_TS_CONFIGFILE_PATH", ""),
+		AuthKey:                               defaultEnvs([]string{"TS_AUTHKEY", "TS_AUTH_KEY"}, ""),
+		Hostname:                              defaultEnv("TS_HOSTNAME", ""),
+		Routes:                                defaultEnvStringPointer("TS_ROUTES"),
+		ServeConfigPath:                       defaultEnv("TS_SERVE_CONFIG", ""),
+		ProxyTargetIP:                         defaultEnv("TS_DEST_IP", ""),
+		ProxyTargetDNSName:                    defaultEnv("TS_EXPERIMENTAL_DEST_DNS_NAME", ""),
+		TailnetTargetIP:                       defaultEnv("TS_TAILNET_TARGET_IP", ""),
+		TailnetTargetFQDN:                     defaultEnv("TS_TAILNET_TARGET_FQDN", ""),
+		DaemonExtraArgs:                       defaultEnv("TS_TAILSCALED_EXTRA_ARGS", ""),
+		ExtraArgs:                             defaultEnv("TS_EXTRA_ARGS", ""),
+		InKubernetes:                          os.Getenv("KUBERNETES_SERVICE_HOST") != "",
+		UserspaceMode:                         defaultBool("TS_USERSPACE", true),
+		StateDir:                              defaultEnv("TS_STATE_DIR", ""),
+		AcceptDNS:                             defaultEnvBoolPointer("TS_ACCEPT_DNS"),
+		KubeSecret:                            defaultEnv("TS_KUBE_SECRET", "tailscale"),
+		SOCKSProxyAddr:                        defaultEnv("TS_SOCKS5_SERVER", ""),
+		HTTPProxyAddr:                         defaultEnv("TS_OUTBOUND_HTTP_PROXY_LISTEN", ""),
+		Socket:                                defaultEnv("TS_SOCKET", "/tmp/tailscaled.sock"),
+		AuthOnce:                              defaultBool("TS_AUTH_ONCE", false),
+		Root:                                  defaultEnv("TS_TEST_ONLY_ROOT", "/"),
+		TailscaledConfigFilePath:              tailscaledConfigFilePath(),
+		AllowProxyingClusterTrafficViaIngress: defaultBool("EXPERIMENTAL_ALLOW_PROXYING_CLUSTER_TRAFFIC_VIA_INGRESS", false),
+		PodIP:                                 defaultEnv("POD_IP", ""),
 	}
+
 	if err := cfg.validate(); err != nil {
 		log.Fatalf("invalid configuration: %v", err)
 	}
@@ -139,8 +162,8 @@ func main() {
 		if err := ensureTunFile(cfg.Root); err != nil {
 			log.Fatalf("Unable to create tuntap device file: %v", err)
 		}
-		if cfg.ProxyTo != "" || cfg.Routes != nil || cfg.TailnetTargetIP != "" || cfg.TailnetTargetFQDN != "" {
-			if err := ensureIPForwarding(cfg.Root, cfg.ProxyTo, cfg.TailnetTargetIP, cfg.TailnetTargetFQDN, cfg.Routes); err != nil {
+		if cfg.ProxyTargetIP != "" || cfg.ProxyTargetDNSName != "" || cfg.Routes != nil || cfg.TailnetTargetIP != "" || cfg.TailnetTargetFQDN != "" {
+			if err := ensureIPForwarding(cfg.Root, cfg.ProxyTargetIP, cfg.TailnetTargetIP, cfg.TailnetTargetFQDN, cfg.Routes); err != nil {
 				log.Printf("Failed to enable IP forwarding: %v", err)
 				log.Printf("To run tailscale as a proxy or router container, IP forwarding must be enabled.")
 				if cfg.InKubernetes {
@@ -152,44 +175,16 @@ func main() {
 		}
 	}
 
-	if cfg.InKubernetes {
-		initKube(cfg.Root)
-	}
-
 	// Context is used for all setup stuff until we're in steady
 	// state, so that if something is hanging we eventually time out
 	// and crashloop the container.
 	bootCtx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
 	defer cancel()
 
-	if cfg.InKubernetes && cfg.KubeSecret != "" {
-		canPatch, err := kc.CheckSecretPermissions(bootCtx, cfg.KubeSecret)
-		if err != nil {
-			log.Fatalf("Some Kubernetes permissions are missing, please check your RBAC configuration: %v", err)
-		}
-		cfg.KubernetesCanPatch = canPatch
-
-		if cfg.AuthKey == "" && !isOneStepConfig(cfg) {
-			key, err := findKeyInKubeSecret(bootCtx, cfg.KubeSecret)
-			if err != nil {
-				log.Fatalf("Getting authkey from kube secret: %v", err)
-			}
-			if key != "" {
-				// This behavior of pulling authkeys from kube secrets was added
-				// at the same time as the patch permission, so we can enforce
-				// that we must be able to patch out the authkey after
-				// authenticating if you want to use this feature. This avoids
-				// us having to deal with the case where we might leave behind
-				// an unnecessary reusable authkey in a secret, like a rake in
-				// the grass.
-				if !cfg.KubernetesCanPatch {
-					log.Fatalf("authkey found in TS_KUBE_SECRET, but the pod doesn't have patch permissions on the secret to manage the authkey.")
-				}
-				log.Print("Using authkey found in kube secret")
-				cfg.AuthKey = key
-			} else {
-				log.Print("No authkey found in kube secret and TS_AUTHKEY not provided, login will be interactive if needed.")
-			}
+	if cfg.InKubernetes {
+		initKubeClient(cfg.Root)
+		if err := cfg.setupKube(bootCtx); err != nil {
+			log.Fatalf("error setting up for running on Kubernetes: %v", err)
 		}
 	}
 
@@ -330,7 +325,7 @@ authLoop:
 	}
 
 	var (
-		wantProxy         = cfg.ProxyTo != "" || cfg.TailnetTargetIP != "" || cfg.TailnetTargetFQDN != ""
+		wantProxy         = cfg.ProxyTargetIP != "" || cfg.ProxyTargetDNSName != "" || cfg.TailnetTargetIP != "" || cfg.TailnetTargetFQDN != "" || cfg.AllowProxyingClusterTrafficViaIngress
 		wantDeviceInfo    = cfg.InKubernetes && cfg.KubeSecret != "" && cfg.KubernetesCanPatch
 		startupTasksDone  = false
 		currentIPs        deephash.Sum // tailscale IPs assigned to device
@@ -338,6 +333,9 @@ authLoop:
 
 		currentEgressIPs deephash.Sum
 
+		addrs        []netip.Prefix
+		backendAddrs []net.IP
+
 		certDomain        = new(atomic.Pointer[string])
 		certDomainChanged = make(chan bool, 1)
 	)
@@ -351,6 +349,44 @@ authLoop:
 			log.Fatalf("error creating new netfilter runner: %v", err)
 		}
 	}
+
+	// Setup for proxies that are configured to proxy to a target specified
+	// by a DNS name (TS_EXPERIMENTAL_DEST_DNS_NAME).
+	const defaultCheckPeriod = time.Minute * 10 // how often to check what IPs the DNS name resolves to
+	var (
+		tc                    = make(chan string, 1)
+		failedResolveAttempts int
+		t                     *time.Timer = time.AfterFunc(defaultCheckPeriod, func() {
+			if cfg.ProxyTargetDNSName != "" {
+				tc <- "recheck"
+			}
+		})
+	)
+	defer t.Stop()
+	// resetTimer resets timer for when to next attempt to resolve the DNS
+	// name for the proxy configured with TS_EXPERIMENTAL_DEST_DNS_NAME. The
+	// timer gets reset to 10 minutes from now unless the last resolution
+	// attempt failed. If one or more consecutive previous resolution
+	// attempts failed, the next resolution attempt will happen after the smallest
+	// of (10 minutes, 2 ^ number-of-consecutive-failed-resolution-attempts
+	// seconds) i.e 2s, 4s, 8s ... 10 minutes.
+	resetTimer := func(lastResolveFailed bool) {
+		if !lastResolveFailed {
+			log.Printf("reconfigureTimer: next DNS resolution attempt in %s", defaultCheckPeriod)
+			t.Reset(defaultCheckPeriod)
+			failedResolveAttempts = 0
+			return
+		}
+		minDelay := 2 // 2 seconds
+		nextTick := time.Second * time.Duration(math.Pow(float64(minDelay), float64(failedResolveAttempts)))
+		if nextTick > defaultCheckPeriod {
+			nextTick = defaultCheckPeriod // cap at 10 minutes
+		}
+		log.Printf("reconfigureTimer: last DNS resolution attempt failed, next DNS resolution attempt in %v", nextTick)
+		t.Reset(nextTick)
+		failedResolveAttempts++
+	}
+
 	notifyChan := make(chan ipn.Notify)
 	errChan := make(chan error)
 	go func() {
@@ -365,6 +401,7 @@ authLoop:
 		}
 	}()
 	var wg sync.WaitGroup
+
 runLoop:
 	for {
 		select {
@@ -387,7 +424,7 @@ runLoop:
 				log.Fatalf("tailscaled left running state (now in state %q), exiting", *n.State)
 			}
 			if n.NetMap != nil {
-				addrs := n.NetMap.SelfNode.Addresses().AsSlice()
+				addrs = n.NetMap.SelfNode.Addresses().AsSlice()
 				newCurrentIPs := deephash.Hash(&addrs)
 				ipsHaveChanged := newCurrentIPs != currentIPs
 
@@ -413,7 +450,7 @@ runLoop:
 					egressAddrs = node.Addresses().AsSlice()
 					newCurentEgressIPs = deephash.Hash(&egressAddrs)
 					egressIPsHaveChanged = newCurentEgressIPs != currentEgressIPs
-					if egressIPsHaveChanged && len(egressAddrs) > 0 {
+					if egressIPsHaveChanged && len(egressAddrs) != 0 {
 						for _, egressAddr := range egressAddrs {
 							ea := egressAddr.Addr()
 							// TODO (irbekrm): make it work for IPv6 too.
@@ -429,13 +466,32 @@ runLoop:
 					}
 					currentEgressIPs = newCurentEgressIPs
 				}
-				if cfg.ProxyTo != "" && len(addrs) > 0 && ipsHaveChanged {
+				if cfg.ProxyTargetIP != "" && len(addrs) != 0 && ipsHaveChanged {
 					log.Printf("Installing proxy rules")
-					if err := installIngressForwardingRule(ctx, cfg.ProxyTo, addrs, nfr); err != nil {
+					if err := installIngressForwardingRule(ctx, cfg.ProxyTargetIP, addrs, nfr); err != nil {
 						log.Fatalf("installing ingress proxy rules: %v", err)
 					}
 				}
-				if cfg.ServeConfigPath != "" && len(n.NetMap.DNS.CertDomains) > 0 {
+				if cfg.ProxyTargetDNSName != "" && len(addrs) != 0 && ipsHaveChanged {
+					newBackendAddrs, err := resolveDNS(ctx, cfg.ProxyTargetDNSName)
+					if err != nil {
+						log.Printf("[unexpected] error resolving DNS name %s: %v", cfg.ProxyTargetDNSName, err)
+						resetTimer(true)
+						continue
+					}
+					backendsHaveChanged := !(slices.EqualFunc(backendAddrs, newBackendAddrs, func(ip1 net.IP, ip2 net.IP) bool {
+						return slices.ContainsFunc(newBackendAddrs, func(ip net.IP) bool { return ip.Equal(ip1) })
+					}))
+					if backendsHaveChanged {
+						log.Printf("installing ingress proxy rules for backends %v", newBackendAddrs)
+						if err := installIngressForwardingRuleForDNSTarget(ctx, newBackendAddrs, addrs, nfr); err != nil {
+							log.Fatalf("error installing ingress proxy rules: %v", err)
+						}
+					}
+					resetTimer(false)
+					backendAddrs = newBackendAddrs
+				}
+				if cfg.ServeConfigPath != "" && len(n.NetMap.DNS.CertDomains) != 0 {
 					cd := n.NetMap.DNS.CertDomains[0]
 					prev := certDomain.Swap(ptr.To(cd))
 					if prev == nil || *prev != cd {
@@ -445,12 +501,24 @@ runLoop:
 						}
 					}
 				}
-				if cfg.TailnetTargetIP != "" && ipsHaveChanged && len(addrs) > 0 {
+				if cfg.TailnetTargetIP != "" && ipsHaveChanged && len(addrs) != 0 {
 					log.Printf("Installing forwarding rules for destination %v", cfg.TailnetTargetIP)
 					if err := installEgressForwardingRule(ctx, cfg.TailnetTargetIP, addrs, nfr); err != nil {
 						log.Fatalf("installing egress proxy rules: %v", err)
 					}
 				}
+				// If this is a L7 cluster ingress proxy (set up
+				// by Kubernetes operator) and proxying of
+				// cluster traffic to the ingress target is
+				// enabled, set up proxy rule each time the
+				// tailnet IPs of this node change (including
+				// the first time they become available).
+				if cfg.AllowProxyingClusterTrafficViaIngress && cfg.ServeConfigPath != "" && ipsHaveChanged && len(addrs) != 0 {
+					log.Printf("installing rules to forward traffic for %s to node's tailnet IP", cfg.PodIP)
+					if err := installTSForwardingRuleForDestination(ctx, cfg.PodIP, addrs, nfr); err != nil {
+						log.Fatalf("installing rules to forward traffic to node's tailnet IP: %v", err)
+					}
+				}
 				currentIPs = newCurrentIPs
 
 				deviceInfo := []any{n.NetMap.SelfNode.StableID(), n.NetMap.SelfNode.Name()}
@@ -467,32 +535,50 @@ runLoop:
 					log.Println("Startup complete, waiting for shutdown signal")
 					startupTasksDone = true
 
-					// Reap all processes, since we are PID1 and need to collect zombies. We can
-					// only start doing this once we've stopped shelling out to things
-					// `tailscale up`, otherwise this goroutine can reap the CLI subprocesses
-					// and wedge bringup.
+					// Wait on tailscaled process. It won't
+					// be cleaned up by default when the
+					// container exits as it is not PID1.
+					// TODO (irbekrm): perhaps we can
+					// replace the reaper by a running
+					// cmd.Wait in a goroutine immediately
+					// after starting tailscaled?
 					reaper := func() {
 						defer wg.Done()
 						for {
 							var status unix.WaitStatus
-							pid, err := unix.Wait4(-1, &status, 0, nil)
+							_, err := unix.Wait4(daemonProcess.Pid, &status, 0, nil)
 							if errors.Is(err, unix.EINTR) {
 								continue
 							}
 							if err != nil {
-								log.Fatalf("Waiting for exited processes: %v", err)
-							}
-							if pid == daemonProcess.Pid {
-								log.Printf("Tailscaled exited")
-								os.Exit(0)
+								log.Fatalf("Waiting for tailscaled to exit: %v", err)
 							}
+							log.Print("tailscaled exited")
+							os.Exit(0)
 						}
-
 					}
 					wg.Add(1)
 					go reaper()
 				}
 			}
+		case <-tc:
+			newBackendAddrs, err := resolveDNS(ctx, cfg.ProxyTargetDNSName)
+			if err != nil {
+				log.Printf("[unexpected] error resolving DNS name %s: %v", cfg.ProxyTargetDNSName, err)
+				resetTimer(true)
+				continue
+			}
+			backendsHaveChanged := !(slices.EqualFunc(backendAddrs, newBackendAddrs, func(ip1 net.IP, ip2 net.IP) bool {
+				return slices.ContainsFunc(newBackendAddrs, func(ip net.IP) bool { return ip.Equal(ip1) })
+			}))
+			if backendsHaveChanged && len(addrs) != 0 {
+				log.Printf("Backend address change detected, installing proxy rules for backends %v", newBackendAddrs)
+				if err := installIngressForwardingRuleForDNSTarget(ctx, newBackendAddrs, addrs, nfr); err != nil {
+					log.Fatalf("installing ingress proxy rules for DNS target %s: %v", cfg.ProxyTargetDNSName, err)
+				}
+			}
+			backendAddrs = newBackendAddrs
+			resetTimer(false)
 		}
 	}
 	wg.Wait()
@@ -733,12 +819,12 @@ func ensureTunFile(root string) error {
 }
 
 // ensureIPForwarding enables IPv4/IPv6 forwarding for the container.
-func ensureIPForwarding(root, clusterProxyTarget, tailnetTargetiP, tailnetTargetFQDN string, routes *string) error {
+func ensureIPForwarding(root, clusterProxyTargetIP, tailnetTargetIP, tailnetTargetFQDN string, routes *string) error {
 	var (
 		v4Forwarding, v6Forwarding bool
 	)
-	if clusterProxyTarget != "" {
-		proxyIP, err := netip.ParseAddr(clusterProxyTarget)
+	if clusterProxyTargetIP != "" {
+		proxyIP, err := netip.ParseAddr(clusterProxyTargetIP)
 		if err != nil {
 			return fmt.Errorf("invalid cluster destination IP: %v", err)
 		}
@@ -748,8 +834,8 @@ func ensureIPForwarding(root, clusterProxyTarget, tailnetTargetiP, tailnetTarget
 			v6Forwarding = true
 		}
 	}
-	if tailnetTargetiP != "" {
-		proxyIP, err := netip.ParseAddr(tailnetTargetiP)
+	if tailnetTargetIP != "" {
+		proxyIP, err := netip.ParseAddr(tailnetTargetIP)
 		if err != nil {
 			return fmt.Errorf("invalid tailnet destination IP: %v", err)
 		}
@@ -777,7 +863,10 @@ func ensureIPForwarding(root, clusterProxyTarget, tailnetTargetiP, tailnetTarget
 			}
 		}
 	}
+	return enableIPForwarding(v4Forwarding, v6Forwarding, root)
+}
 
+func enableIPForwarding(v4Forwarding, v6Forwarding bool, root string) error {
 	var paths []string
 	if v4Forwarding {
 		paths = append(paths, filepath.Join(root, "proc/sys/net/ipv4/ip_forward"))
@@ -837,6 +926,35 @@ func installEgressForwardingRule(ctx context.Context, dstStr string, tsIPs []net
 	return nil
 }
 
+// installTSForwardingRuleForDestination accepts a destination address and a
+// list of node's tailnet addresses, sets up rules to forward traffic for
+// destination to the tailnet IP matching the destination IP family.
+// Destination can be Pod IP of this node.
+func installTSForwardingRuleForDestination(ctx context.Context, dstFilter string, tsIPs []netip.Prefix, nfr linuxfw.NetfilterRunner) error {
+	dst, err := netip.ParseAddr(dstFilter)
+	if err != nil {
+		return err
+	}
+	var local netip.Addr
+	for _, pfx := range tsIPs {
+		if !pfx.IsSingleIP() {
+			continue
+		}
+		if pfx.Addr().Is4() != dst.Is4() {
+			continue
+		}
+		local = pfx.Addr()
+		break
+	}
+	if !local.IsValid() {
+		return fmt.Errorf("no tailscale IP matching family of %s found in %v", dstFilter, tsIPs)
+	}
+	if err := nfr.AddDNATRule(dst, local); err != nil {
+		return fmt.Errorf("installing rule for forwarding traffic to tailnet IP: %w", err)
+	}
+	return nil
+}
+
 func installIngressForwardingRule(ctx context.Context, dstStr string, tsIPs []netip.Prefix, nfr linuxfw.NetfilterRunner) error {
 	dst, err := netip.ParseAddr(dstStr)
 	if err != nil {
@@ -865,15 +983,89 @@ func installIngressForwardingRule(ctx context.Context, dstStr string, tsIPs []ne
 	return nil
 }
 
+func installIngressForwardingRuleForDNSTarget(ctx context.Context, backendAddrs []net.IP, tsIPs []netip.Prefix, nfr linuxfw.NetfilterRunner) error {
+	var (
+		tsv4       netip.Addr
+		tsv6       netip.Addr
+		v4Backends []netip.Addr
+		v6Backends []netip.Addr
+	)
+	for _, pfx := range tsIPs {
+		if pfx.IsSingleIP() && pfx.Addr().Is4() {
+			tsv4 = pfx.Addr()
+			continue
+		}
+		if pfx.IsSingleIP() && pfx.Addr().Is6() {
+			tsv6 = pfx.Addr()
+			continue
+		}
+	}
+	// TODO: log if more than one backend address is found and firewall is
+	// in nftables mode that only the first IP will be used.
+	for _, ip := range backendAddrs {
+		if ip.To4() != nil {
+			v4Backends = append(v4Backends, netip.AddrFrom4([4]byte(ip.To4())))
+		}
+		if ip.To16() != nil {
+			v6Backends = append(v6Backends, netip.AddrFrom16([16]byte(ip.To16())))
+		}
+	}
+
+	// Enable IP forwarding here as opposed to at the start of containerboot
+	// as the IPv4/IPv6 requirements might have changed.
+	// For Kubernetes operator proxies, forwarding for both IPv4 and IPv6 is
+	// enabled by an init container, so in practice enabling forwarding here
+	// is only needed if this proxy has been configured by manually setting
+	// TS_EXPERIMENTAL_DEST_DNS_NAME env var for a containerboot instance.
+	if err := enableIPForwarding(len(v4Backends) != 0, len(v6Backends) != 0, ""); err != nil {
+		log.Printf("[unexpected] failed to ensure IP forwarding: %v", err)
+	}
+
+	updateFirewall := func(dst netip.Addr, backendTargets []netip.Addr) error {
+		if err := nfr.DNATWithLoadBalancer(dst, backendTargets); err != nil {
+			return fmt.Errorf("installing DNAT rules for ingress backends %+#v: %w", backendTargets, err)
+		}
+		// The backend might advertize MSS higher than that of the
+		// tailscale interfaces. Clamp MSS of packets going out via
+		// tailscale0 interface to its MTU to prevent broken connections
+		// in environments where path MTU discovery is not working.
+		if err := nfr.ClampMSSToPMTU("tailscale0", dst); err != nil {
+			return fmt.Errorf("adding rule to clamp traffic via tailscale0: %v", err)
+		}
+		return nil
+	}
+
+	if len(v4Backends) != 0 {
+		if !tsv4.IsValid() {
+			log.Printf("backend targets %v contain at least one IPv4 address, but this node's Tailscale IPs do not contain a valid IPv4 address: %v", backendAddrs, tsIPs)
+		} else if err := updateFirewall(tsv4, v4Backends); err != nil {
+			return fmt.Errorf("Installing IPv4 firewall rules: %w", err)
+		}
+	}
+	if len(v6Backends) != 0 && !tsv6.IsValid() {
+		if !tsv6.IsValid() {
+			log.Printf("backend targets %v contain at least one IPv6 address, but this node's Tailscale IPs do not contain a valid IPv6 address: %v", backendAddrs, tsIPs)
+		} else if !nfr.HasIPV6NAT() {
+			log.Printf("backend targets %v contain at least one IPv6 address, but the chosen firewall mode does not support IPv6 NAT", backendAddrs)
+		} else if err := updateFirewall(tsv6, v6Backends); err != nil {
+			return fmt.Errorf("Installing IPv6 firewall rules: %w", err)
+		}
+	}
+	return nil
+}
+
 // settings is all the configuration for containerboot.
 type settings struct {
 	AuthKey  string
 	Hostname string
 	Routes   *string
-	// ProxyTo is the destination IP to which all incoming
+	// ProxyTargetIP is the destination IP to which all incoming
 	// Tailscale traffic should be proxied. If empty, no proxying
 	// is done. This is typically a locally reachable IP.
-	ProxyTo string
+	ProxyTargetIP string
+	// ProxyTargetDNSName is a DNS name to whose backing IP addresses all
+	// incoming Tailscale traffic should be proxied.
+	ProxyTargetDNSName string
 	// TailnetTargetIP is the destination IP to which all incoming
 	// non-Tailscale traffic should be proxied. This is typically a
 	// Tailscale IP.
@@ -897,17 +1089,38 @@ type settings struct {
 	Root                     string
 	KubernetesCanPatch       bool
 	TailscaledConfigFilePath string
+	// If set to true and, if this containerboot instance is a Kubernetes
+	// ingress proxy, set up rules to forward incoming cluster traffic to be
+	// forwarded to the ingress target in cluster.
+	AllowProxyingClusterTrafficViaIngress bool
+	// PodIP is the IP of the Pod if running in Kubernetes. This is used
+	// when setting up rules to proxy cluster traffic to cluster ingress
+	// target.
+	PodIP string
 }
 
 func (s *settings) validate() error {
 	if s.TailscaledConfigFilePath != "" {
+		dir, file := path.Split(s.TailscaledConfigFilePath)
+		if _, err := os.Stat(dir); err != nil {
+			return fmt.Errorf("error validating whether directory with tailscaled config file %s exists: %w", dir, err)
+		}
+		if _, err := os.Stat(s.TailscaledConfigFilePath); err != nil {
+			return fmt.Errorf("error validating whether tailscaled config directory %q contains tailscaled config for current capability version %q: %w. If this is a Tailscale Kubernetes operator proxy, please ensure that the version of the operator is not older than the version of the proxy", dir, file, err)
+		}
 		if _, err := conffile.Load(s.TailscaledConfigFilePath); err != nil {
 			return fmt.Errorf("error validating tailscaled configfile contents: %w", err)
 		}
 	}
-	if s.ProxyTo != "" && s.UserspaceMode {
+	if s.ProxyTargetIP != "" && s.UserspaceMode {
 		return errors.New("TS_DEST_IP is not supported with TS_USERSPACE")
 	}
+	if s.ProxyTargetDNSName != "" && s.UserspaceMode {
+		return errors.New("TS_EXPERIMENTAL_DEST_DNS_NAME is not supported with TS_USERSPACE")
+	}
+	if s.ProxyTargetDNSName != "" && s.ProxyTargetIP != "" {
+		return errors.New("TS_EXPERIMENTAL_DEST_DNS_NAME and TS_DEST_IP cannot both be set")
+	}
 	if s.TailnetTargetIP != "" && s.UserspaceMode {
 		return errors.New("TS_TAILNET_TARGET_IP is not supported with TS_USERSPACE")
 	}
@@ -918,11 +1131,42 @@ func (s *settings) validate() error {
 		return errors.New("Both TS_TAILNET_TARGET_IP and TS_TAILNET_FQDN cannot be set")
 	}
 	if s.TailscaledConfigFilePath != "" && (s.AcceptDNS != nil || s.AuthKey != "" || s.Routes != nil || s.ExtraArgs != "" || s.Hostname != "") {
-		return errors.New("EXPERIMENTAL_TS_CONFIGFILE_PATH cannot be set in combination with TS_HOSTNAME, TS_EXTRA_ARGS, TS_AUTHKEY, TS_ROUTES, TS_ACCEPT_DNS.")
+		return errors.New("TS_EXPERIMENTAL_VERSIONED_CONFIG_DIR cannot be set in combination with TS_HOSTNAME, TS_EXTRA_ARGS, TS_AUTHKEY, TS_ROUTES, TS_ACCEPT_DNS.")
+	}
+	if s.AllowProxyingClusterTrafficViaIngress && s.UserspaceMode {
+		return errors.New("EXPERIMENTAL_ALLOW_PROXYING_CLUSTER_TRAFFIC_VIA_INGRESS is not supported in userspace mode")
+	}
+	if s.AllowProxyingClusterTrafficViaIngress && s.ServeConfigPath == "" {
+		return errors.New("EXPERIMENTAL_ALLOW_PROXYING_CLUSTER_TRAFFIC_VIA_INGRESS is set but this is not a cluster ingress proxy")
+	}
+	if s.AllowProxyingClusterTrafficViaIngress && s.PodIP == "" {
+		return errors.New("EXPERIMENTAL_ALLOW_PROXYING_CLUSTER_TRAFFIC_VIA_INGRESS is set but POD_IP is not set")
 	}
 	return nil
 }
 
+func resolveDNS(ctx context.Context, name string) ([]net.IP, error) {
+	// TODO (irbekrm): look at using recursive.Resolver instead to resolve
+	// the DNS names as well as retrieve TTLs. It looks though that this
+	// seems to return very short TTLs (shorter than on the actual records).
+	ip4s, err := net.DefaultResolver.LookupIP(ctx, "ip4", name)
+	if err != nil {
+		if e, ok := err.(*net.DNSError); !(ok && e.IsNotFound) {
+			return nil, fmt.Errorf("error looking up IPv4 addresses: %v", err)
+		}
+	}
+	ip6s, err := net.DefaultResolver.LookupIP(ctx, "ip6", name)
+	if err != nil {
+		if e, ok := err.(*net.DNSError); !(ok && e.IsNotFound) {
+			return nil, fmt.Errorf("error looking up IPv6 addresses: %v", err)
+		}
+	}
+	if len(ip4s) == 0 && len(ip6s) == 0 {
+		return nil, fmt.Errorf("no IPv4 or IPv6 addresses found for host: %s", name)
+	}
+	return append(ip4s, ip6s...), nil
+}
+
 // defaultEnv returns the value of the given envvar name, or defVal if
 // unset.
 func defaultEnv(name, defVal string) string {
@@ -1019,3 +1263,42 @@ func isTwoStepConfigAlwaysAuth(cfg *settings) bool {
 func isOneStepConfig(cfg *settings) bool {
 	return cfg.TailscaledConfigFilePath != ""
 }
+
+// tailscaledConfigFilePath returns the path to the tailscaled config file that
+// should be used for the current capability version. It is determined by the
+// TS_EXPERIMENTAL_VERSIONED_CONFIG_DIR environment variable and looks for a
+// file named cap-<capability_version>.hujson in the directory. It searches for
+// the highest capability version that is less than or equal to the current
+// capability version.
+func tailscaledConfigFilePath() string {
+	dir := os.Getenv("TS_EXPERIMENTAL_VERSIONED_CONFIG_DIR")
+	if dir == "" {
+		return ""
+	}
+	fe, err := os.ReadDir(dir)
+	if err != nil {
+		log.Fatalf("error reading tailscaled config directory %q: %v", dir, err)
+	}
+	maxCompatVer := tailcfg.CapabilityVersion(-1)
+	for _, e := range fe {
+		// We don't check if type if file as in most cases this will
+		// come from a mounted kube Secret, where the directory contents
+		// will be various symlinks.
+		if e.Type().IsDir() {
+			continue
+		}
+		cv, err := kubeutils.CapVerFromFileName(e.Name())
+		if err != nil {
+			log.Printf("skipping file %q in tailscaled config directory %q: %v", e.Name(), dir, err)
+			continue
+		}
+		if cv > maxCompatVer && cv <= tailcfg.CurrentCapabilityVersion {
+			maxCompatVer = cv
+		}
+	}
+	if maxCompatVer == -1 {
+		log.Fatalf("no tailscaled config file found in %q for current capability version %q", dir, tailcfg.CurrentCapabilityVersion)
+	}
+	log.Printf("Using tailscaled config file %q for capability version %q", maxCompatVer, tailcfg.CurrentCapabilityVersion)
+	return path.Join(dir, kubeutils.TailscaledConfigFileNameForCap(maxCompatVer))
+}

cmd/containerboot/main_test.go

@@ -65,7 +65,7 @@ func TestContainerBoot(t *testing.T) {
 		"dev/net",
 		"proc/sys/net/ipv4",
 		"proc/sys/net/ipv6/conf/all",
-		"etc",
+		"etc/tailscaled",
 	}
 	for _, path := range dirs {
 		if err := os.MkdirAll(filepath.Join(d, path), 0700); err != nil {
@@ -80,7 +80,7 @@ func TestContainerBoot(t *testing.T) {
 		"dev/net/tun":                           []byte(""),
 		"proc/sys/net/ipv4/ip_forward":          []byte("0"),
 		"proc/sys/net/ipv6/conf/all/forwarding": []byte("0"),
-		"etc/tailscaled":                        tailscaledConfBytes,
+		"etc/tailscaled/cap-95.hujson":          tailscaledConfBytes,
 	}
 	resetFiles := func() {
 		for path, content := range files {
@@ -638,14 +638,14 @@ func TestContainerBoot(t *testing.T) {
 			},
 		},
 		{
-			Name: "experimental tailscaled configfile",
+			Name: "experimental tailscaled config path",
 			Env: map[string]string{
-				"EXPERIMENTAL_TS_CONFIGFILE_PATH": filepath.Join(d, "etc/tailscaled"),
+				"TS_EXPERIMENTAL_VERSIONED_CONFIG_DIR": filepath.Join(d, "etc/tailscaled/"),
 			},
 			Phases: []phase{
 				{
 					WantCmds: []string{
-						"/usr/bin/tailscaled --socket=/tmp/tailscaled.sock --state=mem: --statedir=/tmp --tun=userspace-networking --config=/etc/tailscaled",
+						"/usr/bin/tailscaled --socket=/tmp/tailscaled.sock --state=mem: --statedir=/tmp --tun=userspace-networking --config=/etc/tailscaled/cap-95.hujson",
 					},
 				}, {
 					Notify: runningNotify,

cmd/derper/bootstrap_dns_test.go

@@ -13,6 +13,7 @@ import (
 	"testing"
 
 	"tailscale.com/tstest"
+	"tailscale.com/tstest/nettest"
 )
 
 func BenchmarkHandleBootstrapDNS(b *testing.B) {
@@ -55,6 +56,8 @@ func getBootstrapDNS(t *testing.T, q string) dnsEntryMap {
 }
 
 func TestUnpublishedDNS(t *testing.T) {
+	nettest.SkipIfNoNetwork(t)
+
 	const published = "login.tailscale.com"
 	const unpublished = "log.tailscale.io"
 

cmd/derper/depaware.txt

@@ -11,21 +11,18 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
    W 💣 github.com/dblohm7/wingoes                                   from tailscale.com/util/winutil
         github.com/fxamacker/cbor/v2                                 from tailscale.com/tka
         github.com/golang/groupcache/lru                             from tailscale.com/net/dnscache
-        github.com/golang/protobuf/proto                             from github.com/matttproud/golang_protobuf_extensions/pbutil
    L    github.com/google/nftables                                   from tailscale.com/util/linuxfw
    L 💣 github.com/google/nftables/alignedbuff                       from github.com/google/nftables/xt
    L 💣 github.com/google/nftables/binaryutil                        from github.com/google/nftables+
    L    github.com/google/nftables/expr                              from github.com/google/nftables+
    L    github.com/google/nftables/internal/parseexprfunc            from github.com/google/nftables+
    L    github.com/google/nftables/xt                                from github.com/google/nftables/expr+
-        github.com/google/uuid                                       from tailscale.com/tsweb
+        github.com/google/uuid                                       from tailscale.com/util/fastuuid
         github.com/hdevalence/ed25519consensus                       from tailscale.com/tka
    L    github.com/josharian/native                                  from github.com/mdlayher/netlink+
-   L 💣 github.com/jsimonetti/rtnetlink                              from tailscale.com/net/interfaces+
+   L 💣 github.com/jsimonetti/rtnetlink                              from tailscale.com/net/netmon
    L    github.com/jsimonetti/rtnetlink/internal/unix                from github.com/jsimonetti/rtnetlink
-        github.com/klauspost/compress/flate                          from nhooyr.io/websocket
-        github.com/matttproud/golang_protobuf_extensions/pbutil      from github.com/prometheus/common/expfmt
-   L 💣 github.com/mdlayher/netlink                                  from github.com/jsimonetti/rtnetlink+
+   L 💣 github.com/mdlayher/netlink                                  from github.com/google/nftables+
    L 💣 github.com/mdlayher/netlink/nlenc                            from github.com/jsimonetti/rtnetlink+
    L    github.com/mdlayher/netlink/nltest                           from github.com/google/nftables
    L 💣 github.com/mdlayher/socket                                   from github.com/mdlayher/netlink
@@ -49,13 +46,15 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
    L    github.com/vishvananda/netns                                 from github.com/tailscale/netlink+
         github.com/x448/float16                                      from github.com/fxamacker/cbor/v2
      💣 go4.org/mem                                                  from tailscale.com/client/tailscale+
-        go4.org/netipx                                               from tailscale.com/wgengine/filter+
-   W 💣 golang.zx2c4.com/wireguard/windows/tunnel/winipcfg           from tailscale.com/net/interfaces+
-        google.golang.org/protobuf/encoding/prototext                from github.com/golang/protobuf/proto+
-        google.golang.org/protobuf/encoding/protowire                from github.com/golang/protobuf/proto+
+        go4.org/netipx                                               from tailscale.com/net/tsaddr+
+   W 💣 golang.zx2c4.com/wireguard/windows/tunnel/winipcfg           from tailscale.com/net/netmon+
+        google.golang.org/protobuf/encoding/protodelim               from github.com/prometheus/common/expfmt
+        google.golang.org/protobuf/encoding/prototext                from github.com/prometheus/common/expfmt+
+        google.golang.org/protobuf/encoding/protowire                from google.golang.org/protobuf/encoding/protodelim+
         google.golang.org/protobuf/internal/descfmt                  from google.golang.org/protobuf/internal/filedesc
         google.golang.org/protobuf/internal/descopts                 from google.golang.org/protobuf/internal/filedesc+
         google.golang.org/protobuf/internal/detrand                  from google.golang.org/protobuf/internal/descfmt+
+        google.golang.org/protobuf/internal/editiondefaults          from google.golang.org/protobuf/internal/filedesc
         google.golang.org/protobuf/internal/encoding/defval          from google.golang.org/protobuf/internal/encoding/tag+
         google.golang.org/protobuf/internal/encoding/messageset      from google.golang.org/protobuf/encoding/prototext+
         google.golang.org/protobuf/internal/encoding/tag             from google.golang.org/protobuf/internal/impl
@@ -71,16 +70,15 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         google.golang.org/protobuf/internal/set                      from google.golang.org/protobuf/encoding/prototext
      💣 google.golang.org/protobuf/internal/strs                     from google.golang.org/protobuf/encoding/prototext+
         google.golang.org/protobuf/internal/version                  from google.golang.org/protobuf/runtime/protoimpl
-        google.golang.org/protobuf/proto                             from github.com/golang/protobuf/proto+
-        google.golang.org/protobuf/reflect/protodesc                 from github.com/golang/protobuf/proto
-     💣 google.golang.org/protobuf/reflect/protoreflect              from github.com/golang/protobuf/proto+
-        google.golang.org/protobuf/reflect/protoregistry             from github.com/golang/protobuf/proto+
-        google.golang.org/protobuf/runtime/protoiface                from github.com/golang/protobuf/proto+
-        google.golang.org/protobuf/runtime/protoimpl                 from github.com/golang/protobuf/proto+
-        google.golang.org/protobuf/types/descriptorpb                from google.golang.org/protobuf/reflect/protodesc
+        google.golang.org/protobuf/proto                             from github.com/prometheus/client_golang/prometheus+
+     💣 google.golang.org/protobuf/reflect/protoreflect              from github.com/prometheus/client_model/go+
+        google.golang.org/protobuf/reflect/protoregistry             from google.golang.org/protobuf/encoding/prototext+
+        google.golang.org/protobuf/runtime/protoiface                from google.golang.org/protobuf/internal/impl+
+        google.golang.org/protobuf/runtime/protoimpl                 from github.com/prometheus/client_model/go+
         google.golang.org/protobuf/types/known/timestamppb           from github.com/prometheus/client_golang/prometheus+
         nhooyr.io/websocket                                          from tailscale.com/cmd/derper+
         nhooyr.io/websocket/internal/errd                            from nhooyr.io/websocket
+        nhooyr.io/websocket/internal/util                            from nhooyr.io/websocket
         nhooyr.io/websocket/internal/xsync                           from nhooyr.io/websocket
         tailscale.com                                                from tailscale.com/version
         tailscale.com/atomicfile                                     from tailscale.com/cmd/derper+
@@ -89,18 +87,19 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         tailscale.com/derp                                           from tailscale.com/cmd/derper+
         tailscale.com/derp/derphttp                                  from tailscale.com/cmd/derper
         tailscale.com/disco                                          from tailscale.com/derp
-        tailscale.com/envknob                                        from tailscale.com/derp+
-        tailscale.com/health                                         from tailscale.com/net/tlsdial
-        tailscale.com/hostinfo                                       from tailscale.com/net/interfaces+
+        tailscale.com/drive                                          from tailscale.com/client/tailscale+
+        tailscale.com/envknob                                        from tailscale.com/client/tailscale+
+        tailscale.com/health                                         from tailscale.com/net/tlsdial+
+        tailscale.com/hostinfo                                       from tailscale.com/net/netmon+
         tailscale.com/ipn                                            from tailscale.com/client/tailscale
         tailscale.com/ipn/ipnstate                                   from tailscale.com/client/tailscale+
         tailscale.com/metrics                                        from tailscale.com/cmd/derper+
         tailscale.com/net/dnscache                                   from tailscale.com/derp/derphttp
         tailscale.com/net/flowtrack                                  from tailscale.com/net/packet+
-     💣 tailscale.com/net/interfaces                                 from tailscale.com/net/netns+
+        tailscale.com/net/ktimeout                                   from tailscale.com/cmd/derper
         tailscale.com/net/netaddr                                    from tailscale.com/ipn+
         tailscale.com/net/netknob                                    from tailscale.com/net/netns
-        tailscale.com/net/netmon                                     from tailscale.com/net/sockstats+
+     💣 tailscale.com/net/netmon                                     from tailscale.com/derp/derphttp+
         tailscale.com/net/netns                                      from tailscale.com/derp/derphttp
         tailscale.com/net/netutil                                    from tailscale.com/client/tailscale
         tailscale.com/net/packet                                     from tailscale.com/wgengine/filter
@@ -117,17 +116,17 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         tailscale.com/syncs                                          from tailscale.com/cmd/derper+
         tailscale.com/tailcfg                                        from tailscale.com/client/tailscale+
         tailscale.com/tka                                            from tailscale.com/client/tailscale+
-   W    tailscale.com/tsconst                                        from tailscale.com/net/interfaces
+   W    tailscale.com/tsconst                                        from tailscale.com/net/netmon
         tailscale.com/tstime                                         from tailscale.com/derp+
         tailscale.com/tstime/mono                                    from tailscale.com/tstime/rate
-        tailscale.com/tstime/rate                                    from tailscale.com/wgengine/filter+
+        tailscale.com/tstime/rate                                    from tailscale.com/derp+
         tailscale.com/tsweb                                          from tailscale.com/cmd/derper
         tailscale.com/tsweb/promvarz                                 from tailscale.com/tsweb
         tailscale.com/tsweb/varz                                     from tailscale.com/tsweb+
         tailscale.com/types/dnstype                                  from tailscale.com/tailcfg
         tailscale.com/types/empty                                    from tailscale.com/ipn
         tailscale.com/types/ipproto                                  from tailscale.com/net/flowtrack+
-        tailscale.com/types/key                                      from tailscale.com/cmd/derper+
+        tailscale.com/types/key                                      from tailscale.com/client/tailscale+
         tailscale.com/types/lazy                                     from tailscale.com/version+
         tailscale.com/types/logger                                   from tailscale.com/cmd/derper+
         tailscale.com/types/netmap                                   from tailscale.com/ipn
@@ -136,34 +135,36 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         tailscale.com/types/preftype                                 from tailscale.com/ipn
         tailscale.com/types/ptr                                      from tailscale.com/hostinfo+
         tailscale.com/types/structs                                  from tailscale.com/ipn+
-        tailscale.com/types/tkatype                                  from tailscale.com/types/key+
-        tailscale.com/types/views                                    from tailscale.com/ipn/ipnstate+
-        tailscale.com/util/clientmetric                              from tailscale.com/net/tshttpproxy+
+        tailscale.com/types/tkatype                                  from tailscale.com/client/tailscale+
+        tailscale.com/types/views                                    from tailscale.com/ipn+
+        tailscale.com/util/cibuild                                   from tailscale.com/health
+        tailscale.com/util/clientmetric                              from tailscale.com/net/netmon+
         tailscale.com/util/cloudenv                                  from tailscale.com/hostinfo+
    W    tailscale.com/util/cmpver                                    from tailscale.com/net/tshttpproxy
-        tailscale.com/util/cmpx                                      from tailscale.com/cmd/derper+
         tailscale.com/util/ctxkey                                    from tailscale.com/tsweb+
    L 💣 tailscale.com/util/dirwalk                                   from tailscale.com/metrics
         tailscale.com/util/dnsname                                   from tailscale.com/hostinfo+
+        tailscale.com/util/fastuuid                                  from tailscale.com/tsweb
         tailscale.com/util/httpm                                     from tailscale.com/client/tailscale
         tailscale.com/util/lineread                                  from tailscale.com/hostinfo+
    L    tailscale.com/util/linuxfw                                   from tailscale.com/net/netns
-        tailscale.com/util/mak                                       from tailscale.com/syncs+
+        tailscale.com/util/mak                                       from tailscale.com/health+
         tailscale.com/util/multierr                                  from tailscale.com/health+
         tailscale.com/util/nocasemaps                                from tailscale.com/types/ipproto
-        tailscale.com/util/set                                       from tailscale.com/health+
+        tailscale.com/util/set                                       from tailscale.com/derp+
         tailscale.com/util/singleflight                              from tailscale.com/net/dnscache
         tailscale.com/util/slicesx                                   from tailscale.com/cmd/derper+
         tailscale.com/util/syspolicy                                 from tailscale.com/ipn
-        tailscale.com/util/vizerror                                  from tailscale.com/tsweb+
+        tailscale.com/util/vizerror                                  from tailscale.com/tailcfg+
    W 💣 tailscale.com/util/winutil                                   from tailscale.com/hostinfo+
+   W 💣 tailscale.com/util/winutil/winenv                            from tailscale.com/hostinfo
         tailscale.com/version                                        from tailscale.com/derp+
-        tailscale.com/version/distro                                 from tailscale.com/hostinfo+
+        tailscale.com/version/distro                                 from tailscale.com/envknob+
         tailscale.com/wgengine/filter                                from tailscale.com/types/netmap
         golang.org/x/crypto/acme                                     from golang.org/x/crypto/acme/autocert
         golang.org/x/crypto/acme/autocert                            from tailscale.com/cmd/derper
         golang.org/x/crypto/argon2                                   from tailscale.com/tka
-        golang.org/x/crypto/blake2b                                  from golang.org/x/crypto/nacl/box+
+        golang.org/x/crypto/blake2b                                  from golang.org/x/crypto/argon2+
         golang.org/x/crypto/blake2s                                  from tailscale.com/tka
         golang.org/x/crypto/chacha20                                 from golang.org/x/crypto/chacha20poly1305
         golang.org/x/crypto/chacha20poly1305                         from crypto/tls
@@ -183,10 +184,10 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         golang.org/x/net/proxy                                       from tailscale.com/net/netns
    D    golang.org/x/net/route                                       from net+
         golang.org/x/sync/errgroup                                   from github.com/mdlayher/socket+
-        golang.org/x/sys/cpu                                         from golang.org/x/crypto/blake2b+
-  LD    golang.org/x/sys/unix                                        from github.com/jsimonetti/rtnetlink/internal/unix+
-   W    golang.org/x/sys/windows                                     from golang.org/x/sys/windows/registry+
-   W    golang.org/x/sys/windows/registry                            from golang.zx2c4.com/wireguard/windows/tunnel/winipcfg+
+        golang.org/x/sys/cpu                                         from github.com/josharian/native+
+  LD    golang.org/x/sys/unix                                        from github.com/google/nftables+
+   W    golang.org/x/sys/windows                                     from github.com/dblohm7/wingoes+
+   W    golang.org/x/sys/windows/registry                            from github.com/dblohm7/wingoes+
    W    golang.org/x/sys/windows/svc                                 from golang.org/x/sys/windows/svc/mgr+
    W    golang.org/x/sys/windows/svc/mgr                             from tailscale.com/util/winutil
         golang.org/x/text/secure/bidirule                            from golang.org/x/net/idna
@@ -198,10 +199,10 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         bytes                                                        from bufio+
         cmp                                                          from slices+
         compress/flate                                               from compress/gzip+
-        compress/gzip                                                from internal/profile+
+        compress/gzip                                                from google.golang.org/protobuf/internal/impl+
         container/list                                               from crypto/tls+
         context                                                      from crypto/tls+
-        crypto                                                       from crypto/ecdsa+
+        crypto                                                       from crypto/ecdh+
         crypto/aes                                                   from crypto/ecdsa+
         crypto/cipher                                                from crypto/aes+
         crypto/des                                                   from crypto/tls+
@@ -226,14 +227,14 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         embed                                                        from crypto/internal/nistec+
         encoding                                                     from encoding/json+
         encoding/asn1                                                from crypto/x509+
-        encoding/base32                                              from tailscale.com/tka+
+        encoding/base32                                              from github.com/fxamacker/cbor/v2+
         encoding/base64                                              from encoding/json+
         encoding/binary                                              from compress/gzip+
         encoding/hex                                                 from crypto/x509+
         encoding/json                                                from expvar+
         encoding/pem                                                 from crypto/tls+
         errors                                                       from bufio+
-        expvar                                                       from tailscale.com/cmd/derper+
+        expvar                                                       from github.com/prometheus/client_golang/prometheus+
         flag                                                         from tailscale.com/cmd/derper+
         fmt                                                          from compress/flate+
         go/token                                                     from google.golang.org/protobuf/internal/strs
@@ -247,12 +248,13 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         io/ioutil                                                    from github.com/mitchellh/go-ps+
         log                                                          from expvar+
         log/internal                                                 from log
-        maps                                                         from tailscale.com/types/views+
+        maps                                                         from tailscale.com/ipn+
         math                                                         from compress/flate+
         math/big                                                     from crypto/dsa+
         math/bits                                                    from compress/flate+
         math/rand                                                    from github.com/mdlayher/netlink+
-        mime                                                         from mime/multipart+
+        math/rand/v2                                                 from tailscale.com/util/fastuuid
+        mime                                                         from github.com/prometheus/common/expfmt+
         mime/multipart                                               from net/http
         mime/quotedprintable                                         from mime/multipart
         net                                                          from crypto/tls+
@@ -264,15 +266,15 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
         net/textproto                                                from golang.org/x/net/http/httpguts+
         net/url                                                      from crypto/x509+
         os                                                           from crypto/rand+
-        os/exec                                                      from golang.zx2c4.com/wireguard/windows/tunnel/winipcfg+
+        os/exec                                                      from github.com/coreos/go-iptables/iptables+
         os/signal                                                    from tailscale.com/cmd/derper
    W    os/user                                                      from tailscale.com/util/winutil
-        path                                                         from golang.org/x/crypto/acme/autocert+
+        path                                                         from github.com/prometheus/client_golang/prometheus/internal+
         path/filepath                                                from crypto/x509+
         reflect                                                      from crypto/x509+
-        regexp                                                       from internal/profile+
+        regexp                                                       from github.com/coreos/go-iptables/iptables+
         regexp/syntax                                                from regexp
-        runtime/debug                                                from golang.org/x/crypto/acme+
+        runtime/debug                                                from github.com/prometheus/client_golang/prometheus+
         runtime/metrics                                              from github.com/prometheus/client_golang/prometheus+
         runtime/pprof                                                from net/http/pprof
         runtime/trace                                                from net/http/pprof+

cmd/derper/derper.go

@@ -5,6 +5,7 @@
 package main // import "tailscale.com/cmd/derper"
 
 import (
+	"cmp"
 	"context"
 	"crypto/tls"
 	"encoding/json"
@@ -25,38 +26,47 @@ import (
 	"syscall"
 	"time"
 
-	"go4.org/mem"
 	"golang.org/x/time/rate"
 	"tailscale.com/atomicfile"
 	"tailscale.com/derp"
 	"tailscale.com/derp/derphttp"
 	"tailscale.com/metrics"
+	"tailscale.com/net/ktimeout"
 	"tailscale.com/net/stunserver"
 	"tailscale.com/tsweb"
 	"tailscale.com/types/key"
-	"tailscale.com/util/cmpx"
+	"tailscale.com/types/logger"
+	"tailscale.com/version"
 )
 
 var (
-	dev        = flag.Bool("dev", false, "run in localhost development mode (overrides -a)")
-	addr       = flag.String("a", ":443", "server HTTP/HTTPS listen address, in form \":port\", \"ip:port\", or for IPv6 \"[ip]:port\". If the IP is omitted, it defaults to all interfaces. Serves HTTPS if the port is 443 and/or -certmode is manual, otherwise HTTP.")
-	httpPort   = flag.Int("http-port", 80, "The port on which to serve HTTP. Set to -1 to disable. The listener is bound to the same IP (if any) as specified in the -a flag.")
-	stunPort   = flag.Int("stun-port", 3478, "The UDP port on which to serve STUN. The listener is bound to the same IP (if any) as specified in the -a flag.")
-	configPath = flag.String("c", "", "config file path")
-	certMode   = flag.String("certmode", "letsencrypt", "mode for getting a cert. possible options: manual, letsencrypt")
-	certDir    = flag.String("certdir", tsweb.DefaultCertDir("derper-certs"), "directory to store LetsEncrypt certs, if addr's port is :443")
-	hostname   = flag.String("hostname", "derp.tailscale.com", "LetsEncrypt host name, if addr's port is :443")
-	runSTUN    = flag.Bool("stun", true, "whether to run a STUN server. It will bind to the same IP (if any) as the --addr flag value.")
-	runDERP    = flag.Bool("derp", true, "whether to run a DERP server. The only reason to set this false is if you're decommissioning a server but want to keep its bootstrap DNS functionality still running.")
+	dev         = flag.Bool("dev", false, "run in localhost development mode (overrides -a)")
+	versionFlag = flag.Bool("version", false, "print version and exit")
+	addr        = flag.String("a", ":443", "server HTTP/HTTPS listen address, in form \":port\", \"ip:port\", or for IPv6 \"[ip]:port\". If the IP is omitted, it defaults to all interfaces. Serves HTTPS if the port is 443 and/or -certmode is manual, otherwise HTTP.")
+	httpPort    = flag.Int("http-port", 80, "The port on which to serve HTTP. Set to -1 to disable. The listener is bound to the same IP (if any) as specified in the -a flag.")
+	stunPort    = flag.Int("stun-port", 3478, "The UDP port on which to serve STUN. The listener is bound to the same IP (if any) as specified in the -a flag.")
+	configPath  = flag.String("c", "", "config file path")
+	certMode    = flag.String("certmode", "letsencrypt", "mode for getting a cert. possible options: manual, letsencrypt")
+	certDir     = flag.String("certdir", tsweb.DefaultCertDir("derper-certs"), "directory to store LetsEncrypt certs, if addr's port is :443")
+	hostname    = flag.String("hostname", "derp.tailscale.com", "LetsEncrypt host name, if addr's port is :443")
+	runSTUN     = flag.Bool("stun", true, "whether to run a STUN server. It will bind to the same IP (if any) as the --addr flag value.")
+	runDERP     = flag.Bool("derp", true, "whether to run a DERP server. The only reason to set this false is if you're decommissioning a server but want to keep its bootstrap DNS functionality still running.")
 
-	meshPSKFile    = flag.String("mesh-psk-file", defaultMeshPSKFile(), "if non-empty, path to file containing the mesh pre-shared key file. It should contain some hex string; whitespace is trimmed.")
-	meshWith       = flag.String("mesh-with", "", "optional comma-separated list of hostnames to mesh with; the server's own hostname can be in the list")
-	bootstrapDNS   = flag.String("bootstrap-dns-names", "", "optional comma-separated list of hostnames to make available at /bootstrap-dns")
-	unpublishedDNS = flag.String("unpublished-bootstrap-dns-names", "", "optional comma-separated list of hostnames to make available at /bootstrap-dns and not publish in the list")
-	verifyClients  = flag.Bool("verify-clients", false, "verify clients to this DERP server through a local tailscaled instance.")
+	meshPSKFile     = flag.String("mesh-psk-file", defaultMeshPSKFile(), "if non-empty, path to file containing the mesh pre-shared key file. It should contain some hex string; whitespace is trimmed.")
+	meshWith        = flag.String("mesh-with", "", "optional comma-separated list of hostnames to mesh with; the server's own hostname can be in the list")
+	bootstrapDNS    = flag.String("bootstrap-dns-names", "", "optional comma-separated list of hostnames to make available at /bootstrap-dns")
+	unpublishedDNS  = flag.String("unpublished-bootstrap-dns-names", "", "optional comma-separated list of hostnames to make available at /bootstrap-dns and not publish in the list")
+	verifyClients   = flag.Bool("verify-clients", false, "verify clients to this DERP server through a local tailscaled instance.")
+	verifyClientURL = flag.String("verify-client-url", "", "if non-empty, an admission controller URL for permitting client connections; see tailcfg.DERPAdmitClientRequest")
+	verifyFailOpen  = flag.Bool("verify-client-url-fail-open", true, "whether we fail open if --verify-client-url is unreachable")
 
 	acceptConnLimit = flag.Float64("accept-connection-limit", math.Inf(+1), "rate limit for accepting new connection")
 	acceptConnBurst = flag.Int("accept-connection-burst", math.MaxInt, "burst limit for accepting new connection")
+
+	// tcpKeepAlive is intentionally long, to reduce battery cost. There is an L7 keepalive on a higher frequency schedule.
+	tcpKeepAlive = flag.Duration("tcp-keepalive-time", 10*time.Minute, "TCP keepalive time")
+	// tcpUserTimeout is intentionally short, so that hung connections are cleaned up promptly. DERPs should be nearby users.
+	tcpUserTimeout = flag.Duration("tcp-user-timeout", 15*time.Second, "TCP user timeout")
 )
 
 var (
@@ -121,6 +131,10 @@ func writeNewConfig() config {
 
 func main() {
 	flag.Parse()
+	if *versionFlag {
+		fmt.Println(version.Long())
+		return
+	}
 
 	ctx, cancel := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
 	defer cancel()
@@ -147,6 +161,8 @@ func main() {
 
 	s := derp.NewServer(cfg.PrivateKey, log.Printf)
 	s.SetVerifyClient(*verifyClients)
+	s.SetVerifyClientURL(*verifyClientURL)
+	s.SetVerifyClientURLFailOpen(*verifyFailOpen)
 
 	if *meshPSKFile != "" {
 		b, err := os.ReadFile(*meshPSKFile)
@@ -175,7 +191,12 @@ func main() {
 			http.Error(w, "derp server disabled", http.StatusNotFound)
 		}))
 	}
-	mux.HandleFunc("/derp/probe", probeHandler)
+
+	// These two endpoints are the same. Different versions of the clients
+	// have assumes different paths over time so we support both.
+	mux.HandleFunc("/derp/probe", derphttp.ProbeHandler)
+	mux.HandleFunc("/derp/latency-check", derphttp.ProbeHandler)
+
 	go refreshBootstrapDNSLoop()
 	mux.HandleFunc("/bootstrap-dns", tsweb.BrowserHeaderHandlerFunc(handleBootstrapDNS))
 	mux.Handle("/", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -216,7 +237,16 @@ func main() {
 	}))
 	debug.Handle("traffic", "Traffic check", http.HandlerFunc(s.ServeDebugTraffic))
 
-	quietLogger := log.New(logFilter{}, "", 0)
+	// Longer lived DERP connections send an application layer keepalive. Note
+	// if the keepalive is hit, the user timeout will take precedence over the
+	// keepalive counter, so the probe if unanswered will take effect promptly,
+	// this is less tolerant of high loss, but high loss is unexpected.
+	lc := net.ListenConfig{
+		Control:   ktimeout.UserTimeout(*tcpUserTimeout),
+		KeepAlive: *tcpKeepAlive,
+	}
+
+	quietLogger := log.New(logger.HTTPServerLogFilter{Inner: log.Printf}, "", 0)
 	httpsrv := &http.Server{
 		Addr:     *addr,
 		Handler:  mux,
@@ -292,7 +322,12 @@ func main() {
 					// duration exceeds server's WriteTimeout".
 					WriteTimeout: 5 * time.Minute,
 				}
-				err := port80srv.ListenAndServe()
+				ln, err := lc.Listen(context.Background(), "tcp", port80srv.Addr)
+				if err != nil {
+					log.Fatal(err)
+				}
+				defer ln.Close()
+				err = port80srv.Serve(ln)
 				if err != nil {
 					if err != http.ErrServerClosed {
 						log.Fatal(err)
@@ -300,10 +335,15 @@ func main() {
 				}
 			}()
 		}
-		err = rateLimitedListenAndServeTLS(httpsrv)
+		err = rateLimitedListenAndServeTLS(httpsrv, &lc)
 	} else {
 		log.Printf("derper: serving on %s", *addr)
-		err = httpsrv.ListenAndServe()
+		var ln net.Listener
+		ln, err = lc.Listen(context.Background(), "tcp", httpsrv.Addr)
+		if err != nil {
+			log.Fatal(err)
+		}
+		err = httpsrv.Serve(ln)
 	}
 	if err != nil && err != http.ErrServerClosed {
 		log.Fatalf("derper: %v", err)
@@ -335,17 +375,6 @@ func isChallengeChar(c rune) bool {
 		c == '.' || c == '-' || c == '_'
 }
 
-// probeHandler is the endpoint that js/wasm clients hit to measure
-// DERP latency, since they can't do UDP STUN queries.
-func probeHandler(w http.ResponseWriter, r *http.Request) {
-	switch r.Method {
-	case "HEAD", "GET":
-		w.Header().Set("Access-Control-Allow-Origin", "*")
-	default:
-		http.Error(w, "bogus probe method", http.StatusMethodNotAllowed)
-	}
-}
-
 var validProdHostname = regexp.MustCompile(`^derp([^.]*)\.tailscale\.com\.?$`)
 
 func prodAutocertHostPolicy(_ context.Context, host string) error {
@@ -368,8 +397,8 @@ func defaultMeshPSKFile() string {
 	return ""
 }
 
-func rateLimitedListenAndServeTLS(srv *http.Server) error {
-	ln, err := net.Listen("tcp", cmpx.Or(srv.Addr, ":https"))
+func rateLimitedListenAndServeTLS(srv *http.Server, lc *net.ListenConfig) error {
+	ln, err := lc.Listen(context.Background(), "tcp", cmp.Or(srv.Addr, ":https"))
 	if err != nil {
 		return err
 	}
@@ -423,22 +452,3 @@ func (l *rateLimitedListener) Accept() (net.Conn, error) {
 	l.numAccepts.Add(1)
 	return cn, nil
 }
-
-// logFilter is used to filter out useless error logs that are logged to
-// the net/http.Server.ErrorLog logger.
-type logFilter struct{}
-
-func (logFilter) Write(p []byte) (int, error) {
-	b := mem.B(p)
-	if mem.HasSuffix(b, mem.S(": EOF\n")) ||
-		mem.HasSuffix(b, mem.S(": i/o timeout\n")) ||
-		mem.HasSuffix(b, mem.S(": read: connection reset by peer\n")) ||
-		mem.HasSuffix(b, mem.S(": remote error: tls: bad certificate\n")) ||
-		mem.HasSuffix(b, mem.S(": tls: first record does not look like a TLS handshake\n")) {
-		// Skip this log message, but say that we processed it
-		return len(p), nil
-	}
-
-	log.Printf("%s", p)
-	return len(p), nil
-}

cmd/derper/mesh.go

@@ -15,6 +15,7 @@ import (
 
 	"tailscale.com/derp"
 	"tailscale.com/derp/derphttp"
+	"tailscale.com/net/netmon"
 	"tailscale.com/types/key"
 	"tailscale.com/types/logger"
 )
@@ -36,7 +37,8 @@ func startMesh(s *derp.Server) error {
 
 func startMeshWithHost(s *derp.Server, host string) error {
 	logf := logger.WithPrefix(log.Printf, fmt.Sprintf("mesh(%q): ", host))
-	c, err := derphttp.NewClient(s.PrivateKey(), "https://"+host+"/derp", logf)
+	netMon := netmon.NewStatic() // good enough for cmd/derper; no need for netns fanciness
+	c, err := derphttp.NewClient(s.PrivateKey(), "https://"+host+"/derp", logf, netMon)
 	if err != nil {
 		return err
 	}

cmd/derpprobe/derpprobe.go

@@ -16,21 +16,40 @@ import (
 
 	"tailscale.com/prober"
 	"tailscale.com/tsweb"
+	"tailscale.com/version"
 )
 
 var (
-	derpMapURL = flag.String("derp-map", "https://login.tailscale.com/derpmap/default", "URL to DERP map (https:// or file://)")
-	listen     = flag.String("listen", ":8030", "HTTP listen address")
-	probeOnce  = flag.Bool("once", false, "probe once and print results, then exit; ignores the listen flag")
-	spread     = flag.Bool("spread", true, "whether to spread probing over time")
-	interval   = flag.Duration("interval", 15*time.Second, "probe interval")
+	derpMapURL   = flag.String("derp-map", "https://login.tailscale.com/derpmap/default", "URL to DERP map (https:// or file://)")
+	versionFlag  = flag.Bool("version", false, "print version and exit")
+	listen       = flag.String("listen", ":8030", "HTTP listen address")
+	probeOnce    = flag.Bool("once", false, "probe once and print results, then exit; ignores the listen flag")
+	spread       = flag.Bool("spread", true, "whether to spread probing over time")
+	interval     = flag.Duration("interval", 15*time.Second, "probe interval")
+	meshInterval = flag.Duration("mesh-interval", 15*time.Second, "mesh probe interval")
+	stunInterval = flag.Duration("stun-interval", 15*time.Second, "STUN probe interval")
+	tlsInterval  = flag.Duration("tls-interval", 15*time.Second, "TLS probe interval")
+	bwInterval   = flag.Duration("bw-interval", 0, "bandwidth probe interval (0 = no bandwidth probing)")
+	bwSize       = flag.Int64("bw-probe-size-bytes", 1_000_000, "bandwidth probe size")
 )
 
 func main() {
 	flag.Parse()
+	if *versionFlag {
+		fmt.Println(version.Long())
+		return
+	}
 
 	p := prober.New().WithSpread(*spread).WithOnce(*probeOnce).WithMetricNamespace("derpprobe")
-	dp, err := prober.DERP(p, *derpMapURL, *interval, *interval, *interval)
+	opts := []prober.DERPOpt{
+		prober.WithMeshProbing(*meshInterval),
+		prober.WithSTUNProbing(*stunInterval),
+		prober.WithTLSProbing(*tlsInterval),
+	}
+	if *bwInterval > 0 {
+		opts = append(opts, prober.WithBandwidthProbing(*bwInterval, *bwSize))
+	}
+	dp, err := prober.DERP(p, *derpMapURL, opts...)
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -53,6 +72,7 @@ func main() {
 	mux := http.NewServeMux()
 	tsweb.Debugger(mux)
 	mux.HandleFunc("/", http.HandlerFunc(serveFunc(p)))
+	log.Printf("Listening on %s", *listen)
 	log.Fatal(http.ListenAndServe(*listen, mux))
 }
 

cmd/dist/dist.go

@@ -13,11 +13,16 @@ import (
 
 	"tailscale.com/release/dist"
 	"tailscale.com/release/dist/cli"
+	"tailscale.com/release/dist/qnap"
 	"tailscale.com/release/dist/synology"
 	"tailscale.com/release/dist/unixpkgs"
 )
 
-var synologyPackageCenter bool
+var (
+	synologyPackageCenter bool
+	qnapPrivateKeyPath    string
+	qnapCertificatePath   string
+)
 
 func getTargets() ([]dist.Target, error) {
 	var ret []dist.Target
@@ -33,7 +38,14 @@ func getTargets() ([]dist.Target, error) {
 	// Since only we can provide packages to Synology for
 	// distribution, we default to building the "sideload" variant of
 	// packages that we distribute on pkgs.tailscale.com.
+	//
+	// To build for package center, run
+	// ./tool/go run ./cmd/dist build --synology-package-center synology
 	ret = append(ret, synology.Targets(synologyPackageCenter, nil)...)
+	if (qnapPrivateKeyPath == "") != (qnapCertificatePath == "") {
+		return nil, errors.New("both --qnap-private-key-path and --qnap-certificate-path must be set")
+	}
+	ret = append(ret, qnap.Targets(qnapPrivateKeyPath, qnapCertificatePath)...)
 	return ret, nil
 }
 
@@ -42,6 +54,8 @@ func main() {
 	for _, subcmd := range cmd.Subcommands {
 		if subcmd.Name == "build" {
 			subcmd.FlagSet.BoolVar(&synologyPackageCenter, "synology-package-center", false, "build synology packages with extra metadata for the official package center")
+			subcmd.FlagSet.StringVar(&qnapPrivateKeyPath, "qnap-private-key-path", "", "sign qnap packages with given key (must also provide --qnap-certificate-path)")
+			subcmd.FlagSet.StringVar(&qnapCertificatePath, "qnap-certificate-path", "", "sign qnap packages with given certificate (must also provide --qnap-private-key-path)")
 		}
 	}
 

cmd/get-authkey/main.go

@@ -7,6 +7,7 @@
 package main
 
 import (
+	"cmp"
 	"context"
 	"flag"
 	"fmt"
@@ -16,7 +17,6 @@ import (
 
 	"golang.org/x/oauth2/clientcredentials"
 	"tailscale.com/client/tailscale"
-	"tailscale.com/util/cmpx"
 )
 
 func main() {
@@ -40,7 +40,7 @@ func main() {
 		log.Fatal("at least one tag must be specified")
 	}
 
-	baseURL := cmpx.Or(os.Getenv("TS_BASE_URL"), "https://api.tailscale.com")
+	baseURL := cmp.Or(os.Getenv("TS_BASE_URL"), "https://api.tailscale.com")
 
 	credentials := clientcredentials.Config{
 		ClientID:     clientID,

cmd/gitops-pusher/gitops-pusher.go

@@ -158,11 +158,13 @@ func main() {
 	if !ok && (!oiok || !osok) {
 		log.Fatal("set envvar TS_API_KEY to your Tailscale API key or TS_OAUTH_ID and TS_OAUTH_SECRET to your Tailscale OAuth ID and Secret")
 	}
-	if ok && (oiok || osok) {
+	if apiKey != "" && (oauthId != "" || oauthSecret != "") {
 		log.Fatal("set either the envvar TS_API_KEY or TS_OAUTH_ID and TS_OAUTH_SECRET")
 	}
 	var client *http.Client
-	if oiok {
+	if oiok && (oauthId != "" || oauthSecret != "") {
+		// Both should ideally be set, but if either are non-empty it means the user had an intent
+		// to set _something_, so they should receive the oauth error flow.
 		oauthConfig := &clientcredentials.Config{
 			ClientID:     oauthId,
 			ClientSecret: oauthSecret,

cmd/hello/hello.go

@@ -31,10 +31,12 @@ var (
 //go:embed hello.tmpl.html
 var embeddedTemplate string
 
+var localClient tailscale.LocalClient
+
 func main() {
 	flag.Parse()
 	if *testIP != "" {
-		res, err := tailscale.WhoIs(context.Background(), *testIP)
+		res, err := localClient.WhoIs(context.Background(), *testIP)
 		if err != nil {
 			log.Fatal(err)
 		}
@@ -76,7 +78,7 @@ func main() {
 					GetCertificate: func(hi *tls.ClientHelloInfo) (*tls.Certificate, error) {
 						switch hi.ServerName {
 						case "hello.ts.net":
-							return tailscale.GetCertificate(hi)
+							return localClient.GetCertificate(hi)
 						case "hello.ipn.dev":
 							c, err := tls.LoadX509KeyPair(
 								"/etc/hello/hello.ipn.dev.crt",
@@ -170,7 +172,7 @@ func root(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	who, err := tailscale.WhoIs(r.Context(), r.RemoteAddr)
+	who, err := localClient.WhoIs(r.Context(), r.RemoteAddr)
 	var data tmplData
 	if err != nil {
 		if devMode() {

cmd/hello/hello.tmpl.html

@@ -430,6 +430,8 @@
     <footer class="footer text-gray-600 text-center mb-12">
       <p>Read about <a href="https://tailscale.com/kb/1017/install#advanced-features" class="text-blue-600 hover:text-blue-800"
           target="_blank">what you can do next &rarr;</a></p>
+      <p>Read about <a href="https://tailscale.com/kb/1073/hello" class="text-blue-600 hover:text-blue-800"
+          target="_blank">the Hello service &rarr;</a></p>
     </footer>
   </main>
 </body>

cmd/k8s-nameserver/main.go

@@ -0,0 +1,354 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !plan9
+
+// k8s-nameserver is a simple nameserver implementation meant to be used with
+// k8s-operator to allow to resolve magicDNS names associated with tailnet
+// proxies in cluster.
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"net"
+	"os"
+	"os/signal"
+	"path/filepath"
+	"sync"
+	"syscall"
+
+	"github.com/fsnotify/fsnotify"
+	"github.com/miekg/dns"
+	operatorutils "tailscale.com/k8s-operator"
+	"tailscale.com/util/dnsname"
+)
+
+const (
+	// tsNetDomain is the domain that this DNS nameserver has registered a handler for.
+	tsNetDomain = "ts.net"
+	// addr is the the address that the UDP and TCP listeners will listen on.
+	addr = ":1053"
+
+	// The following constants are specific to the nameserver configuration
+	// provided by a mounted Kubernetes Configmap. The Configmap mounted at
+	// /config is the only supported way for configuring this nameserver.
+	defaultDNSConfigDir    = "/config"
+	kubeletMountedConfigLn = "..data"
+)
+
+// nameserver is a simple nameserver that responds to DNS queries for A records
+// for ts.net domain names over UDP or TCP. It serves DNS responses from
+// in-memory IPv4 host records. It is intended to be deployed on Kubernetes with
+// a ConfigMap mounted at /config that should contain the host records. It
+// dynamically reconfigures its in-memory mappings as the contents of the
+// mounted ConfigMap changes.
+type nameserver struct {
+	// configReader returns the latest desired configuration (host records)
+	// for the nameserver. By default it gets set to a reader that reads
+	// from a Kubernetes ConfigMap mounted at /config, but this can be
+	// overridden in tests.
+	configReader configReaderFunc
+	// configWatcher is a watcher that returns an event when the desired
+	// configuration has changed and the nameserver should update the
+	// in-memory records.
+	configWatcher <-chan string
+
+	mu sync.Mutex // protects following
+	// ip4 are the in-memory hostname -> IP4 mappings that the nameserver
+	// uses to respond to A record queries.
+	ip4 map[dnsname.FQDN][]net.IP
+}
+
+func main() {
+	ctx, cancel := context.WithCancel(context.Background())
+
+	// Ensure that we watch the kube Configmap mounted at /config for
+	// nameserver configuration updates and send events when updates happen.
+	c := ensureWatcherForKubeConfigMap(ctx)
+
+	ns := &nameserver{
+		configReader:  configMapConfigReader,
+		configWatcher: c,
+	}
+
+	// Ensure that in-memory records get set up to date now and will get
+	// reset when the configuration changes.
+	ns.runRecordsReconciler(ctx)
+
+	// Register a DNS server handle for ts.net domain names. Not having a
+	// handle registered for any other domain names is how we enforce that
+	// this nameserver can only be used for ts.net domains - querying any
+	// other domain names returns Rcode Refused.
+	dns.HandleFunc(tsNetDomain, ns.handleFunc())
+
+	// Listen for DNS queries over UDP and TCP.
+	udpSig := make(chan os.Signal)
+	tcpSig := make(chan os.Signal)
+	go listenAndServe("udp", addr, udpSig)
+	go listenAndServe("tcp", addr, tcpSig)
+	sig := make(chan os.Signal, 1)
+	signal.Notify(sig, syscall.SIGINT, syscall.SIGTERM)
+	s := <-sig
+	log.Printf("OS signal (%s) received, shutting down", s)
+	cancel()    // exit the records reconciler and configmap watcher goroutines
+	udpSig <- s // stop the UDP listener
+	tcpSig <- s // stop the TCP listener
+}
+
+// handleFunc is a DNS query handler that can respond to A record queries from
+// the nameserver's in-memory records.
+// - If an A record query is received and the
+// nameserver's in-memory records contain records for the queried domain name,
+// return a success response.
+// - If an A record query is received, but the
+// nameserver's in-memory records do not contain records for the queried domain name,
+// return NXDOMAIN.
+// - If an A record query is received, but the queried domain name is not valid, return Format Error.
+// - If a query is received for any other record type than A, return Not Implemented.
+func (n *nameserver) handleFunc() func(w dns.ResponseWriter, r *dns.Msg) {
+	h := func(w dns.ResponseWriter, r *dns.Msg) {
+		m := new(dns.Msg)
+		defer func() {
+			w.WriteMsg(m)
+		}()
+		if len(r.Question) < 1 {
+			log.Print("[unexpected] nameserver received a request with no questions")
+			m = r.SetRcodeFormatError(r)
+			return
+		}
+		// TODO (irbekrm): maybe set message compression
+		switch r.Question[0].Qtype {
+		case dns.TypeA:
+			q := r.Question[0].Name
+			fqdn, err := dnsname.ToFQDN(q)
+			if err != nil {
+				m = r.SetRcodeFormatError(r)
+				return
+			}
+			// The only supported use of this nameserver is as a
+			// single source of truth for MagicDNS names by
+			// non-tailnet Kubernetes workloads.
+			m.Authoritative = true
+			m.RecursionAvailable = false
+
+			ips := n.lookupIP4(fqdn)
+			if ips == nil || len(ips) == 0 {
+				// As we are the authoritative nameserver for MagicDNS
+				// names, if we do not have a record for this MagicDNS
+				// name, it does not exist.
+				m = m.SetRcode(r, dns.RcodeNameError)
+				return
+			}
+			// TODO (irbekrm): TTL is currently set to 0, meaning
+			// that cluster workloads will not cache the DNS
+			// records. Revisit this in future when we understand
+			// the usage patterns better- is it putting too much
+			// load on kube DNS server or is this fine?
+			for _, ip := range ips {
+				rr := &dns.A{Hdr: dns.RR_Header{Name: q, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 0}, A: ip}
+				m.SetRcode(r, dns.RcodeSuccess)
+				m.Answer = append(m.Answer, rr)
+			}
+		case dns.TypeAAAA:
+			// TODO (irbekrm): implement IPv6 support.
+			// Kubernetes distributions that I am most familiar with
+			// default to IPv4 for Pod CIDR ranges and often many cases don't
+			// support IPv6 at all, so this should not be crucial for now.
+			fallthrough
+		default:
+			log.Printf("[unexpected] nameserver received a query for an unsupported record type: %s", r.Question[0].String())
+			m.SetRcode(r, dns.RcodeNotImplemented)
+		}
+	}
+	return h
+}
+
+// runRecordsReconciler ensures that nameserver's in-memory records are
+// reset when the provided configuration changes.
+func (n *nameserver) runRecordsReconciler(ctx context.Context) {
+	log.Print("updating nameserver's records from the provided configuration...")
+	if err := n.resetRecords(); err != nil { // ensure records are up to date before the nameserver starts
+		log.Fatalf("error setting nameserver's records: %v", err)
+	}
+	log.Print("nameserver's records were updated")
+	go func() {
+		for {
+			select {
+			case <-ctx.Done():
+				log.Printf("context cancelled, exiting records reconciler")
+				return
+			case <-n.configWatcher:
+				log.Print("configuration update detected, resetting records")
+				if err := n.resetRecords(); err != nil {
+					// TODO (irbekrm): this runs in a
+					// container that will be thrown away,
+					// so this should be ok. But maybe still
+					// need to ensure that the DNS server
+					// terminates connections more
+					// gracefully.
+					log.Fatalf("error resetting records: %v", err)
+				}
+				log.Print("nameserver records were reset")
+			}
+		}
+	}()
+}
+
+// resetRecords sets the in-memory DNS records of this nameserver from the
+// provided configuration. It does not check for the diff, so the caller is
+// expected to ensure that this is only called when reset is needed.
+func (n *nameserver) resetRecords() error {
+	dnsCfgBytes, err := n.configReader()
+	if err != nil {
+		log.Printf("error reading nameserver's configuration: %v", err)
+		return err
+	}
+	if dnsCfgBytes == nil || len(dnsCfgBytes) < 1 {
+		log.Print("nameserver's configuration is empty, any in-memory records will be unset")
+		n.mu.Lock()
+		n.ip4 = make(map[dnsname.FQDN][]net.IP)
+		n.mu.Unlock()
+		return nil
+	}
+	dnsCfg := &operatorutils.Records{}
+	err = json.Unmarshal(dnsCfgBytes, dnsCfg)
+	if err != nil {
+		return fmt.Errorf("error unmarshalling nameserver configuration: %v\n", err)
+	}
+
+	if dnsCfg.Version != operatorutils.Alpha1Version {
+		return fmt.Errorf("unsupported configuration version %s, supported versions are %s\n", dnsCfg.Version, operatorutils.Alpha1Version)
+	}
+
+	ip4 := make(map[dnsname.FQDN][]net.IP)
+	defer func() {
+		n.mu.Lock()
+		defer n.mu.Unlock()
+		n.ip4 = ip4
+	}()
+
+	if len(dnsCfg.IP4) == 0 {
+		log.Print("nameserver's configuration contains no records, any in-memory records will be unset")
+		return nil
+	}
+
+	for fqdn, ips := range dnsCfg.IP4 {
+		fqdn, err := dnsname.ToFQDN(fqdn)
+		if err != nil {
+			log.Printf("invalid nameserver's configuration: %s is not a valid FQDN: %v; skipping this record", fqdn, err)
+			continue // one invalid hostname should not break the whole nameserver
+		}
+		for _, ipS := range ips {
+			ip := net.ParseIP(ipS).To4()
+			if ip == nil { // To4 returns nil if IP is not a IPv4 address
+				log.Printf("invalid nameserver's configuration: %v does not appear to be an IPv4 address; skipping this record", ipS)
+				continue // one invalid IP address should not break the whole nameserver
+			}
+			ip4[fqdn] = []net.IP{ip}
+		}
+	}
+	return nil
+}
+
+// listenAndServe starts a DNS server for the provided network and address.
+func listenAndServe(net, addr string, shutdown chan os.Signal) {
+	s := &dns.Server{Addr: addr, Net: net}
+	go func() {
+		<-shutdown
+		log.Printf("shutting down server for %s", net)
+		s.Shutdown()
+	}()
+	log.Printf("listening for %s queries on %s", net, addr)
+	if err := s.ListenAndServe(); err != nil {
+		log.Fatalf("error running %s server: %v", net, err)
+	}
+}
+
+// ensureWatcherForKubeConfigMap sets up a new file watcher for the ConfigMap
+// that's expected to be mounted at /config. Returns a channel that receives an
+// event every time the contents get updated.
+func ensureWatcherForKubeConfigMap(ctx context.Context) chan string {
+	c := make(chan string)
+	watcher, err := fsnotify.NewWatcher()
+	if err != nil {
+		log.Fatalf("error creating a new watcher for the mounted ConfigMap: %v", err)
+	}
+	// kubelet mounts configmap to a Pod using a series of symlinks, one of
+	// which is <mount-dir>/..data that Kubernetes recommends consumers to
+	// use if they need to monitor changes
+	// https://github.com/kubernetes/kubernetes/blob/v1.28.1/pkg/volume/util/atomic_writer.go#L39-L61
+	toWatch := filepath.Join(defaultDNSConfigDir, kubeletMountedConfigLn)
+	go func() {
+		defer watcher.Close()
+		log.Printf("starting file watch for %s", defaultDNSConfigDir)
+		for {
+			select {
+			case <-ctx.Done():
+				log.Print("context cancelled, exiting ConfigMap watcher")
+				return
+			case event, ok := <-watcher.Events:
+				if !ok {
+					log.Fatal("watcher finished; exiting")
+				}
+				if event.Name == toWatch {
+					msg := fmt.Sprintf("ConfigMap update received: %s", event)
+					log.Print(msg)
+					c <- msg
+				}
+			case err, ok := <-watcher.Errors:
+				if err != nil {
+					// TODO (irbekrm): this runs in a
+					// container that will be thrown away,
+					// so this should be ok. But maybe still
+					// need to ensure that the DNS server
+					// terminates connections more
+					// gracefully.
+					log.Fatalf("[unexpected] error watching configuration: %v", err)
+				}
+				if !ok {
+					// TODO (irbekrm): this runs in a
+					// container that will be thrown away,
+					// so this should be ok. But maybe still
+					// need to ensure that the DNS server
+					// terminates connections more
+					// gracefully.
+					log.Fatalf("[unexpected] errors watcher exited")
+				}
+			}
+		}
+	}()
+	if err = watcher.Add(defaultDNSConfigDir); err != nil {
+		log.Fatalf("failed setting up a watcher for the mounted ConfigMap: %v", err)
+	}
+	return c
+}
+
+// configReaderFunc is a function that returns the desired nameserver configuration.
+type configReaderFunc func() ([]byte, error)
+
+// configMapConfigReader reads the desired nameserver configuration from a
+// records.json file in a ConfigMap mounted at /config.
+var configMapConfigReader configReaderFunc = func() ([]byte, error) {
+	if contents, err := os.ReadFile(filepath.Join(defaultDNSConfigDir, operatorutils.DNSRecordsCMKey)); err == nil {
+		return contents, nil
+	} else if os.IsNotExist(err) {
+		return nil, nil
+	} else {
+		return nil, err
+	}
+}
+
+// lookupIP4 returns any IPv4 addresses for the given FQDN from nameserver's
+// in-memory records.
+func (n *nameserver) lookupIP4(fqdn dnsname.FQDN) []net.IP {
+	if n.ip4 == nil {
+		return nil
+	}
+	n.mu.Lock()
+	defer n.mu.Unlock()
+	f := n.ip4[fqdn]
+	return f
+}

cmd/k8s-nameserver/main_test.go

@@ -0,0 +1,227 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !plan9
+
+package main
+
+import (
+	"net"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/miekg/dns"
+	"tailscale.com/util/dnsname"
+)
+
+func TestNameserver(t *testing.T) {
+
+	tests := []struct {
+		name     string
+		ip4      map[dnsname.FQDN][]net.IP
+		query    *dns.Msg
+		wantResp *dns.Msg
+	}{
+		{
+			name: "A record query, record exists",
+			ip4:  map[dnsname.FQDN][]net.IP{dnsname.FQDN("foo.bar.com."): {{1, 2, 3, 4}}},
+			query: &dns.Msg{
+				Question: []dns.Question{{Name: "foo.bar.com", Qtype: dns.TypeA}},
+				MsgHdr:   dns.MsgHdr{Id: 1, RecursionDesired: true},
+			},
+			wantResp: &dns.Msg{
+				Answer: []dns.RR{&dns.A{Hdr: dns.RR_Header{
+					Name: "foo.bar.com", Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 0},
+					A: net.IP{1, 2, 3, 4}}},
+				Question: []dns.Question{{Name: "foo.bar.com", Qtype: dns.TypeA}},
+				MsgHdr: dns.MsgHdr{
+					Id:                 1,
+					Rcode:              dns.RcodeSuccess,
+					RecursionAvailable: false,
+					RecursionDesired:   true,
+					Response:           true,
+					Opcode:             dns.OpcodeQuery,
+					Authoritative:      true,
+				}},
+		},
+		{
+			name: "A record query, record does not exist",
+			ip4:  map[dnsname.FQDN][]net.IP{dnsname.FQDN("foo.bar.com."): {{1, 2, 3, 4}}},
+			query: &dns.Msg{
+				Question: []dns.Question{{Name: "baz.bar.com", Qtype: dns.TypeA}},
+				MsgHdr:   dns.MsgHdr{Id: 1},
+			},
+			wantResp: &dns.Msg{
+				Question: []dns.Question{{Name: "baz.bar.com", Qtype: dns.TypeA}},
+				MsgHdr: dns.MsgHdr{
+					Id:                 1,
+					Rcode:              dns.RcodeNameError,
+					RecursionAvailable: false,
+					Response:           true,
+					Opcode:             dns.OpcodeQuery,
+					Authoritative:      true,
+				}},
+		},
+		{
+			name: "A record query, but the name is not a valid FQDN",
+			ip4:  map[dnsname.FQDN][]net.IP{dnsname.FQDN("foo.bar.com."): {{1, 2, 3, 4}}},
+			query: &dns.Msg{
+				Question: []dns.Question{{Name: "foo..bar.com", Qtype: dns.TypeA}},
+				MsgHdr:   dns.MsgHdr{Id: 1},
+			},
+			wantResp: &dns.Msg{
+				Question: []dns.Question{{Name: "foo..bar.com", Qtype: dns.TypeA}},
+				MsgHdr: dns.MsgHdr{
+					Id:       1,
+					Rcode:    dns.RcodeFormatError,
+					Response: true,
+					Opcode:   dns.OpcodeQuery,
+				}},
+		},
+		{
+			name: "AAAA record query",
+			ip4:  map[dnsname.FQDN][]net.IP{dnsname.FQDN("foo.bar.com."): {{1, 2, 3, 4}}},
+			query: &dns.Msg{
+				Question: []dns.Question{{Name: "foo.bar.com", Qtype: dns.TypeAAAA}},
+				MsgHdr:   dns.MsgHdr{Id: 1},
+			},
+			wantResp: &dns.Msg{
+				Question: []dns.Question{{Name: "foo.bar.com", Qtype: dns.TypeAAAA}},
+				MsgHdr: dns.MsgHdr{
+					Id:       1,
+					Rcode:    dns.RcodeNotImplemented,
+					Response: true,
+					Opcode:   dns.OpcodeQuery,
+				}},
+		},
+		{
+			name: "AAAA record query",
+			ip4:  map[dnsname.FQDN][]net.IP{dnsname.FQDN("foo.bar.com."): {{1, 2, 3, 4}}},
+			query: &dns.Msg{
+				Question: []dns.Question{{Name: "foo.bar.com", Qtype: dns.TypeAAAA}},
+				MsgHdr:   dns.MsgHdr{Id: 1},
+			},
+			wantResp: &dns.Msg{
+				Question: []dns.Question{{Name: "foo.bar.com", Qtype: dns.TypeAAAA}},
+				MsgHdr: dns.MsgHdr{
+					Id:       1,
+					Rcode:    dns.RcodeNotImplemented,
+					Response: true,
+					Opcode:   dns.OpcodeQuery,
+				}},
+		},
+		{
+			name: "CNAME record query",
+			ip4:  map[dnsname.FQDN][]net.IP{dnsname.FQDN("foo.bar.com."): {{1, 2, 3, 4}}},
+			query: &dns.Msg{
+				Question: []dns.Question{{Name: "foo.bar.com", Qtype: dns.TypeCNAME}},
+				MsgHdr:   dns.MsgHdr{Id: 1},
+			},
+			wantResp: &dns.Msg{
+				Question: []dns.Question{{Name: "foo.bar.com", Qtype: dns.TypeCNAME}},
+				MsgHdr: dns.MsgHdr{
+					Id:       1,
+					Rcode:    dns.RcodeNotImplemented,
+					Response: true,
+					Opcode:   dns.OpcodeQuery,
+				}},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ns := &nameserver{
+				ip4: tt.ip4,
+			}
+			handler := ns.handleFunc()
+			fakeRespW := &fakeResponseWriter{}
+			handler(fakeRespW, tt.query)
+			if diff := cmp.Diff(*fakeRespW.msg, *tt.wantResp); diff != "" {
+				t.Fatalf("unexpected response (-got +want): \n%s", diff)
+			}
+		})
+	}
+}
+
+func TestResetRecords(t *testing.T) {
+	tests := []struct {
+		name     string
+		config   []byte
+		hasIp4   map[dnsname.FQDN][]net.IP
+		wantsIp4 map[dnsname.FQDN][]net.IP
+		wantsErr bool
+	}{
+		{
+			name:     "previously empty nameserver.ip4 gets set",
+			config:   []byte(`{"version": "v1alpha1", "ip4": {"foo.bar.com": ["1.2.3.4"]}}`),
+			wantsIp4: map[dnsname.FQDN][]net.IP{"foo.bar.com.": {{1, 2, 3, 4}}},
+		},
+		{
+			name:     "nameserver.ip4 gets reset",
+			hasIp4:   map[dnsname.FQDN][]net.IP{"baz.bar.com.": {{1, 1, 3, 3}}},
+			config:   []byte(`{"version": "v1alpha1", "ip4": {"foo.bar.com": ["1.2.3.4"]}}`),
+			wantsIp4: map[dnsname.FQDN][]net.IP{"foo.bar.com.": {{1, 2, 3, 4}}},
+		},
+		{
+			name:     "configuration with incompatible version",
+			hasIp4:   map[dnsname.FQDN][]net.IP{"baz.bar.com.": {{1, 1, 3, 3}}},
+			config:   []byte(`{"version": "v1beta1", "ip4": {"foo.bar.com": ["1.2.3.4"]}}`),
+			wantsIp4: map[dnsname.FQDN][]net.IP{"baz.bar.com.": {{1, 1, 3, 3}}},
+			wantsErr: true,
+		},
+		{
+			name:     "nameserver.ip4 gets reset to empty config when no configuration is provided",
+			hasIp4:   map[dnsname.FQDN][]net.IP{"baz.bar.com.": {{1, 1, 3, 3}}},
+			wantsIp4: make(map[dnsname.FQDN][]net.IP),
+		},
+		{
+			name:     "nameserver.ip4 gets reset to empty config when the provided configuration is empty",
+			hasIp4:   map[dnsname.FQDN][]net.IP{"baz.bar.com.": {{1, 1, 3, 3}}},
+			config:   []byte(`{"version": "v1alpha1", "ip4": {}}`),
+			wantsIp4: make(map[dnsname.FQDN][]net.IP),
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ns := &nameserver{
+				ip4:          tt.hasIp4,
+				configReader: func() ([]byte, error) { return tt.config, nil },
+			}
+			if err := ns.resetRecords(); err == nil == tt.wantsErr {
+				t.Errorf("resetRecords() returned err: %v, wantsErr: %v", err, tt.wantsErr)
+			}
+			if diff := cmp.Diff(ns.ip4, tt.wantsIp4); diff != "" {
+				t.Fatalf("unexpected nameserver.ip4 contents (-got +want): \n%s", diff)
+			}
+		})
+	}
+}
+
+// fakeResponseWriter is a faked out dns.ResponseWriter that can be used in
+// tests that need to read the response message that was written.
+type fakeResponseWriter struct {
+	msg *dns.Msg
+}
+
+var _ dns.ResponseWriter = &fakeResponseWriter{}
+
+func (fr *fakeResponseWriter) WriteMsg(msg *dns.Msg) error {
+	fr.msg = msg
+	return nil
+}
+func (fr *fakeResponseWriter) LocalAddr() net.Addr {
+	return nil
+}
+func (fr *fakeResponseWriter) RemoteAddr() net.Addr {
+	return nil
+}
+func (fr *fakeResponseWriter) Write([]byte) (int, error) {
+	return 0, nil
+}
+func (fr *fakeResponseWriter) Close() error {
+	return nil
+}
+func (fr *fakeResponseWriter) TsigStatus() error {
+	return nil
+}
+func (fr *fakeResponseWriter) TsigTimersOnly(bool) {}
+func (fr *fakeResponseWriter) Hijack()             {}

cmd/k8s-operator/connector.go

@@ -164,6 +164,17 @@ func (a *ConnectorReconciler) maybeProvisionConnector(ctx context.Context, logge
 		hostname = string(cn.Spec.Hostname)
 	}
 	crl := childResourceLabels(cn.Name, a.tsnamespace, "connector")
+
+	proxyClass := cn.Spec.ProxyClass
+	if proxyClass != "" {
+		if ready, err := proxyClassIsReady(ctx, proxyClass, a.Client); err != nil {
+			return fmt.Errorf("error verifying ProxyClass for Connector: %w", err)
+		} else if !ready {
+			logger.Infof("ProxyClass %s specified for the Connector, but is not (yet) Ready, waiting..", proxyClass)
+			return nil
+		}
+	}
+
 	sts := &tailscaleSTSConfig{
 		ParentResourceName:  cn.Name,
 		ParentResourceUID:   string(cn.UID),
@@ -173,6 +184,7 @@ func (a *ConnectorReconciler) maybeProvisionConnector(ctx context.Context, logge
 		Connector: &connector{
 			isExitNode: cn.Spec.ExitNode,
 		},
+		ProxyClass: proxyClass,
 	}
 
 	if cn.Spec.SubnetRouter != nil && len(cn.Spec.SubnetRouter.AdvertiseRoutes) > 0 {

cmd/k8s-operator/connector_test.go

@@ -67,45 +67,40 @@ func TestConnector(t *testing.T) {
 	fullName, shortName := findGenName(t, fc, "", "test", "connector")
 
 	opts := configOpts{
-		stsName:                    shortName,
-		secretName:                 fullName,
-		parentType:                 "connector",
-		hostname:                   "test-connector",
-		shouldUseDeclarativeConfig: true,
-		isExitNode:                 true,
-		subnetRoutes:               "10.40.0.0/14",
-		confFileHash:               "9321660203effb80983eaecc7b5ac5a8c53934926f46e895b9fe295dcfc5a904",
+		stsName:      shortName,
+		secretName:   fullName,
+		parentType:   "connector",
+		hostname:     "test-connector",
+		isExitNode:   true,
+		subnetRoutes: "10.40.0.0/14",
 	}
-	expectEqual(t, fc, expectedSecret(t, opts))
-	expectEqual(t, fc, expectedSTS(opts))
+	expectEqual(t, fc, expectedSecret(t, opts), nil)
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
 
 	// Add another route to be advertised.
 	mustUpdate[tsapi.Connector](t, fc, "", "test", func(conn *tsapi.Connector) {
 		conn.Spec.SubnetRouter.AdvertiseRoutes = []tsapi.Route{"10.40.0.0/14", "10.44.0.0/20"}
 	})
 	opts.subnetRoutes = "10.40.0.0/14,10.44.0.0/20"
-	opts.confFileHash = "fb6c4daf67425f983985750cd8d6f2beae77e614fcb34176604571f5623d6862"
 	expectReconciled(t, cr, "", "test")
 
-	expectEqual(t, fc, expectedSTS(opts))
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
 
 	// Remove a route.
 	mustUpdate[tsapi.Connector](t, fc, "", "test", func(conn *tsapi.Connector) {
 		conn.Spec.SubnetRouter.AdvertiseRoutes = []tsapi.Route{"10.44.0.0/20"}
 	})
 	opts.subnetRoutes = "10.44.0.0/20"
-	opts.confFileHash = "bacba177bcfe3849065cf6fee53d658a9bb4144197ac5b861727d69ea99742bb"
 	expectReconciled(t, cr, "", "test")
-	expectEqual(t, fc, expectedSTS(opts))
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
 
 	// Remove the subnet router.
 	mustUpdate[tsapi.Connector](t, fc, "", "test", func(conn *tsapi.Connector) {
 		conn.Spec.SubnetRouter = nil
 	})
 	opts.subnetRoutes = ""
-	opts.confFileHash = "7c421a99128eb80e79a285a82702f19f8f720615542a15bd794858a6275d8079"
 	expectReconciled(t, cr, "", "test")
-	expectEqual(t, fc, expectedSTS(opts))
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
 
 	// Re-add the subnet router.
 	mustUpdate[tsapi.Connector](t, fc, "", "test", func(conn *tsapi.Connector) {
@@ -114,9 +109,8 @@ func TestConnector(t *testing.T) {
 		}
 	})
 	opts.subnetRoutes = "10.44.0.0/20"
-	opts.confFileHash = "bacba177bcfe3849065cf6fee53d658a9bb4144197ac5b861727d69ea99742bb"
 	expectReconciled(t, cr, "", "test")
-	expectEqual(t, fc, expectedSTS(opts))
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
 
 	// Delete the Connector.
 	if err = fc.Delete(context.Background(), cn); err != nil {
@@ -152,25 +146,22 @@ func TestConnector(t *testing.T) {
 	fullName, shortName = findGenName(t, fc, "", "test", "connector")
 
 	opts = configOpts{
-		stsName:                    shortName,
-		secretName:                 fullName,
-		parentType:                 "connector",
-		shouldUseDeclarativeConfig: true,
-		subnetRoutes:               "10.40.0.0/14",
-		hostname:                   "test-connector",
-		confFileHash:               "57d922331890c9b1c8c6ae664394cb254334c551d9cd9db14537b5d9da9fb17e",
+		stsName:      shortName,
+		secretName:   fullName,
+		parentType:   "connector",
+		subnetRoutes: "10.40.0.0/14",
+		hostname:     "test-connector",
 	}
-	expectEqual(t, fc, expectedSecret(t, opts))
-	expectEqual(t, fc, expectedSTS(opts))
+	expectEqual(t, fc, expectedSecret(t, opts), nil)
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
 
 	// Add an exit node.
 	mustUpdate[tsapi.Connector](t, fc, "", "test", func(conn *tsapi.Connector) {
 		conn.Spec.ExitNode = true
 	})
 	opts.isExitNode = true
-	opts.confFileHash = "1499b591fd97a50f0330db6ec09979792c49890cf31f5da5bb6a3f50dba1e77a"
 	expectReconciled(t, cr, "", "test")
-	expectEqual(t, fc, expectedSTS(opts))
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
 
 	// Delete the Connector.
 	if err = fc.Delete(context.Background(), cn); err != nil {
@@ -183,3 +174,103 @@ func TestConnector(t *testing.T) {
 	expectMissing[appsv1.StatefulSet](t, fc, "operator-ns", shortName)
 	expectMissing[corev1.Secret](t, fc, "operator-ns", fullName)
 }
+
+func TestConnectorWithProxyClass(t *testing.T) {
+	// Setup
+	pc := &tsapi.ProxyClass{
+		ObjectMeta: metav1.ObjectMeta{Name: "custom-metadata"},
+		Spec: tsapi.ProxyClassSpec{StatefulSet: &tsapi.StatefulSet{
+			Labels:      map[string]string{"foo": "bar"},
+			Annotations: map[string]string{"bar.io/foo": "some-val"},
+			Pod:         &tsapi.Pod{Annotations: map[string]string{"foo.io/bar": "some-val"}}}},
+	}
+	cn := &tsapi.Connector{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "test",
+			UID:  types.UID("1234-UID"),
+		},
+		TypeMeta: metav1.TypeMeta{
+			Kind:       tsapi.ConnectorKind,
+			APIVersion: "tailscale.io/v1alpha1",
+		},
+		Spec: tsapi.ConnectorSpec{
+			SubnetRouter: &tsapi.SubnetRouter{
+				AdvertiseRoutes: []tsapi.Route{"10.40.0.0/14"},
+			},
+			ExitNode: true,
+		},
+	}
+	fc := fake.NewClientBuilder().
+		WithScheme(tsapi.GlobalScheme).
+		WithObjects(pc, cn).
+		WithStatusSubresource(pc, cn).
+		Build()
+	ft := &fakeTSClient{}
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+	cl := tstest.NewClock(tstest.ClockOpts{})
+	cr := &ConnectorReconciler{
+		Client: fc,
+		clock:  cl,
+		ssr: &tailscaleSTSReconciler{
+			Client:            fc,
+			tsClient:          ft,
+			defaultTags:       []string{"tag:k8s"},
+			operatorNamespace: "operator-ns",
+			proxyImage:        "tailscale/tailscale",
+		},
+		logger: zl.Sugar(),
+	}
+
+	// 1. Connector is created with no ProxyClass specified, create
+	// resources with the default configuration.
+	expectReconciled(t, cr, "", "test")
+	fullName, shortName := findGenName(t, fc, "", "test", "connector")
+
+	opts := configOpts{
+		stsName:      shortName,
+		secretName:   fullName,
+		parentType:   "connector",
+		hostname:     "test-connector",
+		isExitNode:   true,
+		subnetRoutes: "10.40.0.0/14",
+	}
+	expectEqual(t, fc, expectedSecret(t, opts), nil)
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
+
+	// 2. Update Connector to specify a ProxyClass. ProxyClass is not yet
+	// ready, so its configuration is NOT applied to the Connector
+	// resources.
+	mustUpdate(t, fc, "", "test", func(conn *tsapi.Connector) {
+		conn.Spec.ProxyClass = "custom-metadata"
+	})
+	expectReconciled(t, cr, "", "test")
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
+
+	// 3. ProxyClass is set to Ready by proxy-class reconciler. Connector
+	// get reconciled and configuration from the ProxyClass is applied to
+	// its resources.
+	mustUpdateStatus(t, fc, "", "custom-metadata", func(pc *tsapi.ProxyClass) {
+		pc.Status = tsapi.ProxyClassStatus{
+			Conditions: []tsapi.ConnectorCondition{{
+				Status:             metav1.ConditionTrue,
+				Type:               tsapi.ProxyClassready,
+				ObservedGeneration: pc.Generation,
+			}}}
+	})
+	opts.proxyClass = pc.Name
+	expectReconciled(t, cr, "", "test")
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
+
+	// 4. Connector.spec.proxyClass field is unset, Connector gets
+	// reconciled and configuration from the ProxyClass is removed from the
+	// cluster resources for the Connector.
+	mustUpdate(t, fc, "", "test", func(conn *tsapi.Connector) {
+		conn.Spec.ProxyClass = ""
+	})
+	opts.proxyClass = ""
+	expectReconciled(t, cr, "", "test")
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
+}

cmd/k8s-operator/deploy/chart/templates/deployment.yaml

@@ -21,6 +21,9 @@ spec:
       {{- end }}
       labels:
         app: operator
+        {{- with .Values.operatorConfig.podLabels }}
+        {{- toYaml . | nindent 8 }}
+        {{- end }}
     spec:
       {{- with .Values.imagePullSecrets }}
       imagePullSecrets:
@@ -49,6 +52,8 @@ spec:
           image: {{ .Values.operatorConfig.image.repo }}{{- if .Values.operatorConfig.image.digest -}}{{ printf "@%s" .Values.operatorConfig.image.digest}}{{- else -}}{{ printf "%s" $operatorTag }}{{- end }}
           imagePullPolicy: {{ .Values.operatorConfig.image.pullPolicy }}
           env:
+            - name: OPERATOR_INITIAL_TAGS
+              value: {{ join "," .Values.operatorConfig.defaultTags }}
             - name: OPERATOR_HOSTNAME
               value: {{ .Values.operatorConfig.hostname }}
             - name: OPERATOR_SECRET

cmd/k8s-operator/deploy/chart/templates/operator-rbac.yaml

@@ -22,7 +22,10 @@ rules:
   resources: ["ingressclasses"]
   verbs: ["get", "list", "watch"]
 - apiGroups: ["tailscale.com"]
-  resources: ["connectors", "connectors/status"]
+  resources: ["connectors", "connectors/status", "proxyclasses", "proxyclasses/status"]
+  verbs: ["get", "list", "watch", "update"]
+- apiGroups: ["tailscale.com"]
+  resources: ["dnsconfigs", "dnsconfigs/status"]
   verbs: ["get", "list", "watch", "update"]
 ---
 apiVersion: rbac.authorization.k8s.io/v1
@@ -45,11 +48,14 @@ metadata:
   namespace: {{ .Release.Namespace }}
 rules:
 - apiGroups: [""]
-  resources: ["secrets"]
+  resources: ["secrets", "serviceaccounts", "configmaps"]
   verbs: ["*"]
 - apiGroups: ["apps"]
-  resources: ["statefulsets"]
+  resources: ["statefulsets", "deployments"]
   verbs: ["*"]
+- apiGroups: ["discovery.k8s.io"]
+  resources: ["endpointslices"]
+  verbs: ["get", "list", "watch"]
 ---
 apiVersion: rbac.authorization.k8s.io/v1
 kind: RoleBinding

cmd/k8s-operator/deploy/chart/values.yaml

@@ -12,9 +12,16 @@ oauth: {}
 # of chart installation. We do not use Helm's CRD installation mechanism as that
 # does not allow for upgrading CRDs.
 # https://helm.sh/docs/chart_best_practices/custom_resource_definitions/
-installCRDs: "true"
+installCRDs: true
 
 operatorConfig:
+  # ACL tag that operator will be tagged with. Operator must be made owner of
+  # these tags
+  # https://tailscale.com/kb/1236/kubernetes-operator/?q=operator#setting-up-the-kubernetes-operator
+  # Multiple tags are defined as array items and passed to the operator as a comma-separated string
+  defaultTags:
+    - "tag:k8s-operator"
+
   image:
     repo: tailscale/k8s-operator
     # Digest will be prioritized over tag. If neither are set appVersion will be
@@ -30,6 +37,7 @@ operatorConfig:
   resources: {}
 
   podAnnotations: {}
+  podLabels: {}
 
   tolerations: []
 

cmd/k8s-operator/deploy/crds/tailscale.com_connectors.yaml

@@ -31,6 +31,7 @@ spec:
       name: v1alpha1
       schema:
         openAPIV3Schema:
+          description: 'Connector defines a Tailscale node that will be deployed in the cluster. The node can be configured to act as a Tailscale subnet router and/or a Tailscale exit node. Connector is a cluster-scoped resource. More info: https://tailscale.com/kb/1236/kubernetes-operator#deploying-exit-nodes-and-subnet-routers-on-kubernetes-using-connector-custom-resource'
           type: object
           required:
             - spec
@@ -44,7 +45,7 @@ spec:
             metadata:
               type: object
             spec:
-              description: ConnectorSpec describes the desired Tailscale component.
+              description: 'ConnectorSpec describes the desired Tailscale component. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#spec-and-status'
               type: object
               properties:
                 exitNode:
@@ -54,6 +55,9 @@ spec:
                   description: Hostname is the tailnet hostname that should be assigned to the Connector node. If unset, hostname defaults to <connector name>-connector. Hostname can contain lower case letters, numbers and dashes, it must not start or end with a dash and must be between 2 and 63 characters long.
                   type: string
                   pattern: ^[a-z0-9][a-z0-9-]{0,61}[a-z0-9]$
+                proxyClass:
+                  description: ProxyClass is the name of the ProxyClass custom resource that contains configuration options that should be applied to the resources created for this Connector. If unset, the operator will create resources with the default configuration.
+                  type: string
                 subnetRouter:
                   description: SubnetRouter defines subnet routes that the Connector node should expose to tailnet. If unset, none are exposed. https://tailscale.com/kb/1019/subnets/
                   type: object

cmd/k8s-operator/deploy/crds/tailscale.com_dnsconfigs.yaml

@@ -0,0 +1,96 @@
+apiVersion: apiextensions.k8s.io/v1
+kind: CustomResourceDefinition
+metadata:
+  annotations:
+    controller-gen.kubebuilder.io/version: v0.13.0
+  name: dnsconfigs.tailscale.com
+spec:
+  group: tailscale.com
+  names:
+    kind: DNSConfig
+    listKind: DNSConfigList
+    plural: dnsconfigs
+    shortNames:
+      - dc
+    singular: dnsconfig
+  scope: Cluster
+  versions:
+    - additionalPrinterColumns:
+        - description: Service IP address of the nameserver
+          jsonPath: .status.nameserver.ip
+          name: NameserverIP
+          type: string
+      name: v1alpha1
+      schema:
+        openAPIV3Schema:
+          type: object
+          required:
+            - spec
+          properties:
+            apiVersion:
+              description: 'APIVersion defines the versioned schema of this representation of an object. Servers should convert recognized schemas to the latest internal value, and may reject unrecognized values. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources'
+              type: string
+            kind:
+              description: 'Kind is a string value representing the REST resource this object represents. Servers may infer this from the endpoint the client submits requests to. Cannot be updated. In CamelCase. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds'
+              type: string
+            metadata:
+              type: object
+            spec:
+              type: object
+              required:
+                - nameserver
+              properties:
+                nameserver:
+                  type: object
+                  properties:
+                    image:
+                      type: object
+                      properties:
+                        repo:
+                          type: string
+                        tag:
+                          type: string
+            status:
+              type: object
+              properties:
+                conditions:
+                  type: array
+                  items:
+                    description: ConnectorCondition contains condition information for a Connector.
+                    type: object
+                    required:
+                      - status
+                      - type
+                    properties:
+                      lastTransitionTime:
+                        description: LastTransitionTime is the timestamp corresponding to the last status change of this condition.
+                        type: string
+                        format: date-time
+                      message:
+                        description: Message is a human readable description of the details of the last transition, complementing reason.
+                        type: string
+                      observedGeneration:
+                        description: If set, this represents the .metadata.generation that the condition was set based upon. For instance, if .metadata.generation is currently 12, but the .status.condition[x].observedGeneration is 9, the condition is out of date with respect to the current state of the Connector.
+                        type: integer
+                        format: int64
+                      reason:
+                        description: Reason is a brief machine readable explanation for the condition's last transition.
+                        type: string
+                      status:
+                        description: Status of the condition, one of ('True', 'False', 'Unknown').
+                        type: string
+                      type:
+                        description: Type of the condition, known values are (`SubnetRouterReady`).
+                        type: string
+                  x-kubernetes-list-map-keys:
+                    - type
+                  x-kubernetes-list-type: map
+                nameserver:
+                  type: object
+                  properties:
+                    ip:
+                      type: string
+      served: true
+      storage: true
+      subresources:
+        status: {}

cmd/k8s-operator/deploy/examples/dnsconfig.yaml

@@ -0,0 +1,9 @@
+apiVersion: tailscale.com/v1alpha1
+kind: DNSConfig 
+metadata:
+  name: ts-dns
+spec:
+  nameserver:
+    image:
+      repo: tailscale/k8s-nameserver
+      tag: unstable-v1.65

cmd/k8s-operator/deploy/examples/proxyclass.yaml

@@ -0,0 +1,17 @@
+apiVersion: tailscale.com/v1alpha1
+kind: ProxyClass
+metadata:
+  name: prod
+spec:
+  metrics:
+    enable: true
+  statefulSet:
+    annotations:
+      platform-component: infra
+    pod:
+      labels:
+        team: eng
+      nodeSelector:
+        kubernetes.io/os: "linux"
+      imagePullSecrets:
+      - name: "foo"

cmd/k8s-operator/deploy/manifests/nameserver/cm.yaml

@@ -0,0 +1,4 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: dnsrecords

cmd/k8s-operator/deploy/manifests/nameserver/deploy.yaml

@@ -0,0 +1,37 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: nameserver 
+spec:
+  replicas: 1
+  revisionHistoryLimit: 5
+  selector:
+    matchLabels:
+      app: nameserver
+  strategy:
+    type: Recreate
+  template:
+    metadata:
+      labels:
+        app: nameserver
+    spec:
+      containers:
+      - imagePullPolicy: IfNotPresent
+        name: nameserver
+        ports:
+        - name: tcp
+          protocol: TCP
+          containerPort: 1053
+        - name: udp
+          protocol: UDP
+          containerPort: 1053
+        volumeMounts:
+        - name: dnsrecords
+          mountPath: /config
+      restartPolicy: Always
+      serviceAccount: nameserver
+      serviceAccountName: nameserver
+      volumes:
+      - name: dnsrecords
+        configMap:
+          name: dnsrecords

cmd/k8s-operator/deploy/manifests/nameserver/sa.yaml

@@ -0,0 +1,4 @@
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: nameserver

cmd/k8s-operator/deploy/manifests/nameserver/svc.yaml

@@ -0,0 +1,16 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: nameserver
+spec:
+  selector:
+    app: nameserver
+  ports:
+  - name: udp
+    targetPort: 1053
+    port: 53
+    protocol: UDP
+  - name: tcp
+    targetPort: 1053
+    port: 53
+    protocol: TCP 

cmd/k8s-operator/deploy/manifests/proxy.yaml

@@ -14,10 +14,8 @@ spec:
         - name: sysctler
           securityContext:
             privileged: true
-          command: ["/bin/sh"]
-          args:
-            - -c
-            - sysctl -w net.ipv4.ip_forward=1 net.ipv6.conf.all.forwarding=1
+          command: ["/bin/sh", "-c"]
+          args: [sysctl -w net.ipv4.ip_forward=1 && if sysctl net.ipv6.conf.all.forwarding; then sysctl -w net.ipv6.conf.all.forwarding=1; fi]
       resources:
         requests:
           cpu: 1m
@@ -28,8 +26,10 @@ spec:
           env:
             - name: TS_USERSPACE
               value: "false"
-            - name: TS_AUTH_ONCE
-              value: "true"
+            - name: POD_IP
+              valueFrom:
+                fieldRef:
+                  fieldPath: status.podIP
           securityContext:
             capabilities:
               add:

cmd/k8s-operator/deploy/manifests/userspace-proxy.yaml

@@ -20,5 +20,7 @@ spec:
           env:
             - name: TS_USERSPACE
               value: "true"
-            - name: TS_AUTH_ONCE
-              value: "true"
+            - name: POD_IP
+              valueFrom:
+                fieldRef:
+                  fieldPath: status.podIP

cmd/k8s-operator/dnsrecords.go

@@ -0,0 +1,337 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !plan9
+
+// tailscale-operator provides a way to expose services running in a Kubernetes
+// cluster to your Tailnet and to make Tailscale nodes available to cluster
+// workloads
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"slices"
+
+	"go.uber.org/zap"
+	corev1 "k8s.io/api/core/v1"
+	discoveryv1 "k8s.io/api/discovery/v1"
+	networkingv1 "k8s.io/api/networking/v1"
+	apiequality "k8s.io/apimachinery/pkg/api/equality"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/utils/net"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/reconcile"
+	operatorutils "tailscale.com/k8s-operator"
+	tsapi "tailscale.com/k8s-operator/apis/v1alpha1"
+	"tailscale.com/util/mak"
+)
+
+const (
+	dnsRecordsRecocilerFinalizer = "tailscale.com/dns-records-reconciler"
+	annotationTSMagicDNSName     = "tailscale.com/magic-dnsname"
+)
+
+// dnsRecordsReconciler knows how to update dnsrecords ConfigMap with DNS
+// records.
+// The records that it creates are:
+//   - For tailscale Ingress, a mapping of the Ingress's MagicDNSName to the IP address of
+//     the ingress proxy Pod.
+//   - For egress proxies configured via tailscale.com/tailnet-fqdn annotation, a
+//     mapping of the tailnet FQDN to the IP address of the egress proxy Pod.
+//
+// Records will only be created if there is exactly one ready
+// tailscale.com/v1alpha1.DNSConfig instance in the cluster (so that we know
+// that there is a ts.net nameserver deployed in the cluster).
+type dnsRecordsReconciler struct {
+	client.Client
+	tsNamespace           string // namespace in which we provision tailscale resources
+	logger                *zap.SugaredLogger
+	isDefaultLoadBalancer bool // true if operator is the default ingress controller in this cluster
+}
+
+// Reconcile takes a reconcile.Request for a headless Service fronting a
+// tailscale proxy and updates DNS Records in dnsrecords ConfigMap for the
+// in-cluster ts.net nameserver if required.
+func (dnsRR *dnsRecordsReconciler) Reconcile(ctx context.Context, req reconcile.Request) (res reconcile.Result, err error) {
+	logger := dnsRR.logger.With("Service", req.NamespacedName)
+	logger.Debugf("starting reconcile")
+	defer logger.Debugf("reconcile finished")
+
+	headlessSvc := new(corev1.Service)
+	err = dnsRR.Client.Get(ctx, req.NamespacedName, headlessSvc)
+	if apierrors.IsNotFound(err) {
+		logger.Debugf("Service not found")
+		return reconcile.Result{}, nil
+	}
+	if err != nil {
+		return reconcile.Result{}, fmt.Errorf("failed to get Service: %w", err)
+	}
+	if !(isManagedByType(headlessSvc, "svc") || isManagedByType(headlessSvc, "ingress")) {
+		logger.Debugf("Service is not a headless Service for a tailscale ingress or egress proxy; do nothing")
+		return reconcile.Result{}, nil
+	}
+
+	if !headlessSvc.DeletionTimestamp.IsZero() {
+		logger.Debug("Service is being deleted, clean up resources")
+		return reconcile.Result{}, dnsRR.maybeCleanup(ctx, headlessSvc, logger)
+	}
+
+	// Check that there is a ts.net nameserver deployed to the cluster by
+	// checking that there is tailscale.com/v1alpha1.DNSConfig resource in a
+	// Ready state.
+	dnsCfgLst := new(tsapi.DNSConfigList)
+	if err = dnsRR.List(ctx, dnsCfgLst); err != nil {
+		return reconcile.Result{}, fmt.Errorf("error listing DNSConfigs: %w", err)
+	}
+	if len(dnsCfgLst.Items) == 0 {
+		logger.Debugf("DNSConfig does not exist, not creating DNS records")
+		return reconcile.Result{}, nil
+	}
+	if len(dnsCfgLst.Items) > 1 {
+		logger.Errorf("Invalid cluster state - more than one DNSConfig found in cluster. Please ensure no more than one exists")
+		return reconcile.Result{}, nil
+	}
+	dnsCfg := dnsCfgLst.Items[0]
+	if !operatorutils.DNSCfgIsReady(&dnsCfg) {
+		logger.Info("DNSConfig is not ready yet, waiting...")
+		return reconcile.Result{}, nil
+	}
+
+	return reconcile.Result{}, dnsRR.maybeProvision(ctx, headlessSvc, logger)
+}
+
+// maybeProvision ensures that dnsrecords ConfigMap contains a record for the
+// proxy associated with the headless Service.
+// The record is only provisioned if the proxy is for a tailscale Ingress or
+// egress configured via tailscale.com/tailnet-fqdn annotation.
+//
+// For Ingress, the record is a mapping between the MagicDNSName of the Ingress, retrieved from
+// ingress.status.loadBalancer.ingress.hostname field and the proxy Pod IP addresses
+// retrieved from the EndpoinSlice associated with this headless Service, i.e
+// Records{IP4: <MagicDNS name of the Ingress>: <[IPs of the ingress proxy Pods]>}
+//
+// For egress, the record is a mapping between tailscale.com/tailnet-fqdn
+// annotation and the proxy Pod IP addresses, retrieved from the EndpointSlice
+// associated with this headless Service, i.e
+// Records{IP4: {<tailscale.com/tailnet-fqdn>: <[IPs of the egress proxy Pods]>}
+//
+// If records need to be created for this proxy, maybeProvision will also:
+// - update the headless Service with a tailscale.com/magic-dnsname annotation
+// - update the headless Service with a finalizer
+func (dnsRR *dnsRecordsReconciler) maybeProvision(ctx context.Context, headlessSvc *corev1.Service, logger *zap.SugaredLogger) error {
+	if headlessSvc == nil {
+		logger.Info("[unexpected] maybeProvision called with a nil Service")
+		return nil
+	}
+	isEgressFQDNSvc, err := dnsRR.isSvcForFQDNEgressProxy(ctx, headlessSvc)
+	if err != nil {
+		return fmt.Errorf("error checking whether the Service is for an egress proxy: %w", err)
+	}
+	if !(isEgressFQDNSvc || isManagedByType(headlessSvc, "ingress")) {
+		logger.Debug("Service is not fronting a proxy that we create DNS records for; do nothing")
+		return nil
+	}
+	fqdn, err := dnsRR.fqdnForDNSRecord(ctx, headlessSvc, logger)
+	if err != nil {
+		return fmt.Errorf("error determining DNS name for record: %w", err)
+	}
+	if fqdn == "" {
+		logger.Debugf("MagicDNS name does not (yet) exist, not provisioning DNS record")
+		return nil // a new reconcile will be triggered once it's added
+	}
+
+	oldHeadlessSvc := headlessSvc.DeepCopy()
+	// Ensure that headless Service is annotated with a finalizer to help
+	// with records cleanup when proxy resources are deleted.
+	if !slices.Contains(headlessSvc.Finalizers, dnsRecordsRecocilerFinalizer) {
+		headlessSvc.Finalizers = append(headlessSvc.Finalizers, dnsRecordsRecocilerFinalizer)
+	}
+	// Ensure that headless Service is annotated with the current MagicDNS
+	// name to help with records cleanup when proxy resources are deleted or
+	// MagicDNS name changes.
+	oldFqdn := headlessSvc.Annotations[annotationTSMagicDNSName]
+	if oldFqdn != "" && oldFqdn != fqdn { // i.e user has changed the value of tailscale.com/tailnet-fqdn annotation
+		logger.Debugf("MagicDNS name has changed, remvoving record for %s", oldFqdn)
+		updateFunc := func(rec *operatorutils.Records) {
+			delete(rec.IP4, oldFqdn)
+		}
+		if err = dnsRR.updateDNSConfig(ctx, updateFunc); err != nil {
+			return fmt.Errorf("error removing record for %s: %w", oldFqdn, err)
+		}
+	}
+	mak.Set(&headlessSvc.Annotations, annotationTSMagicDNSName, fqdn)
+	if !apiequality.Semantic.DeepEqual(oldHeadlessSvc, headlessSvc) {
+		logger.Infof("provisioning DNS record for MagicDNS name: %s", fqdn) // this will be printed exactly once
+		if err := dnsRR.Update(ctx, headlessSvc); err != nil {
+			return fmt.Errorf("error updating proxy headless Service metadata: %w", err)
+		}
+	}
+
+	// Get the Pod IP addresses for the proxy from the EndpointSlice for the
+	// headless Service.
+	labels := map[string]string{discoveryv1.LabelServiceName: headlessSvc.Name} // https://kubernetes.io/docs/concepts/services-networking/endpoint-slices/#ownership
+	eps, err := getSingleObject[discoveryv1.EndpointSlice](ctx, dnsRR.Client, dnsRR.tsNamespace, labels)
+	if err != nil {
+		return fmt.Errorf("error getting the EndpointSlice for the proxy's headless Service: %w", err)
+	}
+	if eps == nil {
+		logger.Debugf("proxy's headless Service EndpointSlice does not yet exist. We will reconcile again once it's created")
+		return nil
+	}
+	// An EndpointSlice for a Service can have a list of endpoints that each
+	// can have multiple addresses - these are the IP addresses of any Pods
+	// selected by that Service. Pick all the IPv4 addresses.
+	ips := make([]string, 0)
+	for _, ep := range eps.Endpoints {
+		for _, ip := range ep.Addresses {
+			if !net.IsIPv4String(ip) {
+				logger.Infof("EndpointSlice contains IP address %q that is not IPv4, ignoring. Currently only IPv4 is supported", ip)
+			} else {
+				ips = append(ips, ip)
+			}
+		}
+	}
+	if len(ips) == 0 {
+		logger.Debugf("EndpointSlice for the Service contains no IPv4 addresses. We will reconcile again once they are created.")
+		return nil
+	}
+	updateFunc := func(rec *operatorutils.Records) {
+		mak.Set(&rec.IP4, fqdn, ips)
+	}
+	if err = dnsRR.updateDNSConfig(ctx, updateFunc); err != nil {
+		return fmt.Errorf("error updating DNS records: %w", err)
+	}
+	return nil
+}
+
+// maybeCleanup ensures that the DNS record for the proxy has been removed from
+// dnsrecords ConfigMap and the tailscale.com/dns-records-reconciler finalizer
+// has been removed from the Service. If the record is not found in the
+// ConfigMap, the ConfigMap does not exist, or the Service does not have
+// tailscale.com/magic-dnsname annotation, just remove the finalizer.
+func (h *dnsRecordsReconciler) maybeCleanup(ctx context.Context, headlessSvc *corev1.Service, logger *zap.SugaredLogger) error {
+	ix := slices.Index(headlessSvc.Finalizers, dnsRecordsRecocilerFinalizer)
+	if ix == -1 {
+		logger.Debugf("no finalizer, nothing to do")
+		return nil
+	}
+	cm := &corev1.ConfigMap{}
+	err := h.Client.Get(ctx, types.NamespacedName{Name: operatorutils.DNSRecordsCMName, Namespace: h.tsNamespace}, cm)
+	if apierrors.IsNotFound(err) {
+		logger.Debug("'dsnrecords' ConfigMap not found")
+		return h.removeHeadlessSvcFinalizer(ctx, headlessSvc)
+	}
+	if err != nil {
+		return fmt.Errorf("error retrieving 'dnsrecords' ConfigMap: %w", err)
+	}
+	if cm.Data == nil {
+		logger.Debug("'dnsrecords' ConfigMap contains no records")
+		return h.removeHeadlessSvcFinalizer(ctx, headlessSvc)
+	}
+	_, ok := cm.Data[operatorutils.DNSRecordsCMKey]
+	if !ok {
+		logger.Debug("'dnsrecords' ConfigMap contains no records")
+		return h.removeHeadlessSvcFinalizer(ctx, headlessSvc)
+	}
+	fqdn, _ := headlessSvc.GetAnnotations()[annotationTSMagicDNSName]
+	if fqdn == "" {
+		return h.removeHeadlessSvcFinalizer(ctx, headlessSvc)
+	}
+	logger.Infof("removing DNS record for MagicDNS name %s", fqdn)
+	updateFunc := func(rec *operatorutils.Records) {
+		delete(rec.IP4, fqdn)
+	}
+	if err = h.updateDNSConfig(ctx, updateFunc); err != nil {
+		return fmt.Errorf("error updating DNS config: %w", err)
+	}
+	return h.removeHeadlessSvcFinalizer(ctx, headlessSvc)
+}
+
+func (dnsRR *dnsRecordsReconciler) removeHeadlessSvcFinalizer(ctx context.Context, headlessSvc *corev1.Service) error {
+	idx := slices.Index(headlessSvc.Finalizers, dnsRecordsRecocilerFinalizer)
+	if idx == -1 {
+		return nil
+	}
+	headlessSvc.Finalizers = append(headlessSvc.Finalizers[:idx], headlessSvc.Finalizers[idx+1:]...)
+	return dnsRR.Update(ctx, headlessSvc)
+}
+
+// fqdnForDNSRecord returns MagicDNS name associated with a given headless Service.
+// If the headless Service is for a tailscale Ingress proxy, returns ingress.status.loadBalancer.ingress.hostname.
+// If the headless Service is for an tailscale egress proxy configured via tailscale.com/tailnet-fqdn annotation, returns the annotation value.
+// This function is not expected to be called with headless Services for other
+// proxy types, or any other Services, but it just returns an empty string if
+// that happens.
+func (dnsRR *dnsRecordsReconciler) fqdnForDNSRecord(ctx context.Context, headlessSvc *corev1.Service, logger *zap.SugaredLogger) (string, error) {
+	parentName := parentFromObjectLabels(headlessSvc)
+	if isManagedByType(headlessSvc, "ingress") {
+		ing := new(networkingv1.Ingress)
+		if err := dnsRR.Get(ctx, parentName, ing); err != nil {
+			return "", err
+		}
+		if len(ing.Status.LoadBalancer.Ingress) == 0 {
+			return "", nil
+		}
+		return ing.Status.LoadBalancer.Ingress[0].Hostname, nil
+	}
+	if isManagedByType(headlessSvc, "svc") {
+		svc := new(corev1.Service)
+		if err := dnsRR.Get(ctx, parentName, svc); apierrors.IsNotFound(err) {
+			logger.Info("[unexpected] parent Service for egress proxy %s not found", headlessSvc.Name)
+			return "", nil
+		} else if err != nil {
+			return "", err
+		}
+		return svc.Annotations[AnnotationTailnetTargetFQDN], nil
+	}
+	return "", nil
+}
+
+// updateDNSConfig runs the provided update function against dnsrecords
+// ConfigMap. At this point the in-cluster ts.net nameserver is expected to be
+// successfully created together with the ConfigMap.
+func (dnsRR *dnsRecordsReconciler) updateDNSConfig(ctx context.Context, update func(*operatorutils.Records)) error {
+	cm := &corev1.ConfigMap{}
+	err := dnsRR.Get(ctx, types.NamespacedName{Name: operatorutils.DNSRecordsCMName, Namespace: dnsRR.tsNamespace}, cm)
+	if apierrors.IsNotFound(err) {
+		dnsRR.logger.Info("[unexpected] dnsrecords ConfigMap not found in cluster. Not updating DNS records. Please open an isue and attach operator logs.")
+		return nil
+	}
+	if err != nil {
+		return fmt.Errorf("error retrieving dnsrecords ConfigMap: %w", err)
+	}
+	dnsRecords := operatorutils.Records{Version: operatorutils.Alpha1Version, IP4: map[string][]string{}}
+	if cm.Data != nil && cm.Data[operatorutils.DNSRecordsCMKey] != "" {
+		if err := json.Unmarshal([]byte(cm.Data[operatorutils.DNSRecordsCMKey]), &dnsRecords); err != nil {
+			return err
+		}
+	}
+	update(&dnsRecords)
+	dnsRecordsBs, err := json.Marshal(dnsRecords)
+	if err != nil {
+		return fmt.Errorf("error marshalling DNS records: %w", err)
+	}
+	mak.Set(&cm.Data, operatorutils.DNSRecordsCMKey, string(dnsRecordsBs))
+	return dnsRR.Update(ctx, cm)
+}
+
+// isSvcForFQDNEgressProxy returns true if the Service is a headless Service
+// created for a proxy for a tailscale egress Service configured via
+// tailscale.com/tailnet-fqdn annotation.
+func (dnsRR *dnsRecordsReconciler) isSvcForFQDNEgressProxy(ctx context.Context, svc *corev1.Service) (bool, error) {
+	if !isManagedByType(svc, "svc") {
+		return false, nil
+	}
+	parentName := parentFromObjectLabels(svc)
+	parentSvc := new(corev1.Service)
+	if err := dnsRR.Get(ctx, parentName, parentSvc); apierrors.IsNotFound(err) {
+		return false, nil
+	} else if err != nil {
+		return false, err
+	}
+	annots := parentSvc.Annotations
+	return annots != nil && annots[AnnotationTailnetTargetFQDN] != "", nil
+}

cmd/k8s-operator/dnsrecords_test.go

@@ -0,0 +1,198 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !plan9
+
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"go.uber.org/zap"
+	corev1 "k8s.io/api/core/v1"
+	discoveryv1 "k8s.io/api/discovery/v1"
+	networkingv1 "k8s.io/api/networking/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/client/fake"
+	operatorutils "tailscale.com/k8s-operator"
+	tsapi "tailscale.com/k8s-operator/apis/v1alpha1"
+	"tailscale.com/tstest"
+	"tailscale.com/types/ptr"
+)
+
+func TestDNSRecordsReconciler(t *testing.T) {
+	// Preconfigure a cluster with a DNSConfig
+	dnsConfig := &tsapi.DNSConfig{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "test",
+		},
+		TypeMeta: metav1.TypeMeta{Kind: "DNSConfig"},
+		Spec: tsapi.DNSConfigSpec{
+			Nameserver: &tsapi.Nameserver{},
+		}}
+	ing := &networkingv1.Ingress{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "ts-ingress",
+			Namespace: "test",
+		},
+		Spec: networkingv1.IngressSpec{
+			IngressClassName: ptr.To("tailscale"),
+		},
+		Status: networkingv1.IngressStatus{
+			LoadBalancer: networkingv1.IngressLoadBalancerStatus{
+				Ingress: []networkingv1.IngressLoadBalancerIngress{{
+					Hostname: "cluster.ingress.ts.net"}},
+			},
+		},
+	}
+	cm := &corev1.ConfigMap{ObjectMeta: metav1.ObjectMeta{Name: "dnsrecords", Namespace: "tailscale"}}
+	fc := fake.NewClientBuilder().
+		WithScheme(tsapi.GlobalScheme).
+		WithObjects(cm).
+		WithObjects(dnsConfig).
+		WithObjects(ing).
+		WithStatusSubresource(dnsConfig, ing).
+		Build()
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+	cl := tstest.NewClock(tstest.ClockOpts{})
+	// Set the ready condition of the DNSConfig
+	mustUpdateStatus[tsapi.DNSConfig](t, fc, "", "test", func(c *tsapi.DNSConfig) {
+		operatorutils.SetDNSConfigCondition(c, tsapi.NameserverReady, metav1.ConditionTrue, reasonNameserverCreated, reasonNameserverCreated, 0, cl, zl.Sugar())
+	})
+	dnsRR := &dnsRecordsReconciler{
+		Client:      fc,
+		logger:      zl.Sugar(),
+		tsNamespace: "tailscale",
+	}
+
+	// 1. DNS record is created for an egress proxy configured via
+	// tailscale.com/tailnet-fqdn annotation
+	egressSvcFQDN := &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:        "egress-fqdn",
+			Namespace:   "test",
+			Annotations: map[string]string{"tailscale.com/tailnet-fqdn": "foo.bar.ts.net"},
+		},
+		Spec: corev1.ServiceSpec{
+			ExternalName: "unused",
+			Type:         corev1.ServiceTypeExternalName,
+		},
+	}
+	headlessForEgressSvcFQDN := headlessSvcForParent(egressSvcFQDN, "svc") // create the proxy headless Service
+	ep := endpointSliceForService(headlessForEgressSvcFQDN, "10.9.8.7")
+	mustCreate(t, fc, egressSvcFQDN)
+	mustCreate(t, fc, headlessForEgressSvcFQDN)
+	mustCreate(t, fc, ep)
+	expectReconciled(t, dnsRR, "tailscale", "egress-fqdn") // dns-records-reconciler reconcile the headless Service
+	// ConfigMap should now have a record for foo.bar.ts.net -> 10.8.8.7
+	wantHosts := map[string][]string{"foo.bar.ts.net": {"10.9.8.7"}}
+	expectHostsRecords(t, fc, wantHosts)
+
+	// 2. DNS record is updated if tailscale.com/tailnet-fqdn annotation's
+	// value changes
+	mustUpdate(t, fc, "test", "egress-fqdn", func(svc *corev1.Service) {
+		svc.Annotations["tailscale.com/tailnet-fqdn"] = "baz.bar.ts.net"
+	})
+	expectReconciled(t, dnsRR, "tailscale", "egress-fqdn") // dns-records-reconciler reconcile the headless Service
+	wantHosts = map[string][]string{"baz.bar.ts.net": {"10.9.8.7"}}
+	expectHostsRecords(t, fc, wantHosts)
+
+	// 3. DNS record is updated if the IP address of the proxy Pod changes.
+	ep = endpointSliceForService(headlessForEgressSvcFQDN, "10.6.5.4")
+	mustUpdate(t, fc, ep.Namespace, ep.Name, func(ep *discoveryv1.EndpointSlice) {
+		ep.Endpoints[0].Addresses = []string{"10.6.5.4"}
+	})
+	expectReconciled(t, dnsRR, "tailscale", "egress-fqdn") // dns-records-reconciler reconcile the headless Service
+	wantHosts = map[string][]string{"baz.bar.ts.net": {"10.6.5.4"}}
+	expectHostsRecords(t, fc, wantHosts)
+
+	// 4. DNS record is created for an ingress proxy configured via Ingress
+	headlessForIngress := headlessSvcForParent(ing, "ingress")
+	ep = endpointSliceForService(headlessForIngress, "10.9.8.7")
+	mustCreate(t, fc, headlessForIngress)
+	mustCreate(t, fc, ep)
+	expectReconciled(t, dnsRR, "tailscale", "ts-ingress") // dns-records-reconciler should reconcile the headless Service
+	wantHosts["cluster.ingress.ts.net"] = []string{"10.9.8.7"}
+	expectHostsRecords(t, fc, wantHosts)
+
+	// 5. DNS records are updated if Ingress's MagicDNS name changes (i.e users changed spec.tls.hosts[0])
+	t.Log("test case 5")
+	mustUpdateStatus(t, fc, "test", "ts-ingress", func(ing *networkingv1.Ingress) {
+		ing.Status.LoadBalancer.Ingress[0].Hostname = "another.ingress.ts.net"
+	})
+	expectReconciled(t, dnsRR, "tailscale", "ts-ingress") // dns-records-reconciler should reconcile the headless Service
+	delete(wantHosts, "cluster.ingress.ts.net")
+	wantHosts["another.ingress.ts.net"] = []string{"10.9.8.7"}
+	expectHostsRecords(t, fc, wantHosts)
+
+	// 6. DNS records are updated if Ingress proxy's Pod IP changes
+	mustUpdate(t, fc, ep.Namespace, ep.Name, func(ep *discoveryv1.EndpointSlice) {
+		ep.Endpoints[0].Addresses = []string{"7.8.9.10"}
+	})
+	expectReconciled(t, dnsRR, "tailscale", "ts-ingress")
+	wantHosts["another.ingress.ts.net"] = []string{"7.8.9.10"}
+	expectHostsRecords(t, fc, wantHosts)
+}
+
+func headlessSvcForParent(o client.Object, typ string) *corev1.Service {
+	return &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      o.GetName(),
+			Namespace: "tailscale",
+			Labels: map[string]string{
+				LabelManaged:         "true",
+				LabelParentName:      o.GetName(),
+				LabelParentNamespace: o.GetNamespace(),
+				LabelParentType:      typ,
+			},
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP: "None",
+			Type:      corev1.ServiceTypeClusterIP,
+			Selector:  map[string]string{"foo": "bar"},
+		},
+	}
+}
+
+func endpointSliceForService(svc *corev1.Service, ip string) *discoveryv1.EndpointSlice {
+	return &discoveryv1.EndpointSlice{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      svc.Name,
+			Namespace: svc.Namespace,
+			Labels:    map[string]string{discoveryv1.LabelServiceName: svc.Name},
+		},
+		Endpoints: []discoveryv1.Endpoint{{
+			Addresses: []string{ip},
+		}},
+	}
+}
+
+func expectHostsRecords(t *testing.T, cl client.Client, wantsHosts map[string][]string) {
+	t.Helper()
+	cm := new(corev1.ConfigMap)
+	if err := cl.Get(context.Background(), types.NamespacedName{Name: "dnsrecords", Namespace: "tailscale"}, cm); err != nil {
+		t.Fatalf("getting dnsconfig ConfigMap: %v", err)
+	}
+	if cm.Data == nil {
+		t.Fatal("dnsconfig ConfigMap has no data")
+	}
+	dnsConfigString, ok := cm.Data[operatorutils.DNSRecordsCMKey]
+	if !ok {
+		t.Fatal("dnsconfig ConfigMap does not contain dnsconfig")
+	}
+	dnsConfig := &operatorutils.Records{}
+	if err := json.Unmarshal([]byte(dnsConfigString), dnsConfig); err != nil {
+		t.Fatalf("unmarshaling dnsconfig: %v", err)
+	}
+	if diff := cmp.Diff(dnsConfig.IP4, wantsHosts); diff != "" {
+		t.Fatalf("unexpected dns config (-got +want):\n%s", diff)
+	}
+}

cmd/k8s-operator/generate/main.go

@@ -19,10 +19,14 @@ import (
 )
 
 const (
-	operatorDeploymentFilesPath = "cmd/k8s-operator/deploy"
-	crdPath                     = operatorDeploymentFilesPath + "/crds/tailscale.com_connectors.yaml"
-	helmTemplatesPath           = operatorDeploymentFilesPath + "/chart/templates"
-	crdTemplatePath             = helmTemplatesPath + "/connectors.yaml"
+	operatorDeploymentFilesPath   = "cmd/k8s-operator/deploy"
+	connectorCRDPath              = operatorDeploymentFilesPath + "/crds/tailscale.com_connectors.yaml"
+	proxyClassCRDPath             = operatorDeploymentFilesPath + "/crds/tailscale.com_proxyclasses.yaml"
+	dnsConfigCRDPath              = operatorDeploymentFilesPath + "/crds/tailscale.com_dnsconfigs.yaml"
+	helmTemplatesPath             = operatorDeploymentFilesPath + "/chart/templates"
+	connectorCRDHelmTemplatePath  = helmTemplatesPath + "/connector.yaml"
+	proxyClassCRDHelmTemplatePath = helmTemplatesPath + "/proxyclass.yaml"
+	dnsConfigCRDHelmTemplatePath  = helmTemplatesPath + "/dnsconfig.yaml"
 
 	helmConditionalStart = "{{ if .Values.installCRDs -}}\n"
 	helmConditionalEnd   = "{{- end -}}"
@@ -34,19 +38,19 @@ func main() {
 	}
 	repoRoot := "../../"
 	switch os.Args[1] {
-	case "helmcrd": // insert CRD to Helm templates behind a installCRDs=true conditional check
-		log.Print("Adding Connector CRD to Helm templates")
+	case "helmcrd": // insert CRDs to Helm templates behind a installCRDs=true conditional check
+		log.Print("Adding CRDs to Helm templates")
 		if err := generate("./"); err != nil {
-			log.Fatalf("error adding Connector CRD to Helm templates: %v", err)
+			log.Fatalf("error adding CRDs to Helm templates: %v", err)
 		}
 		return
 	case "staticmanifests": // generate static manifests from Helm templates (including the CRD)
 	default:
 		log.Fatalf("unknown option %s, known options are 'staticmanifests', 'helmcrd'", os.Args[1])
 	}
-	log.Printf("Inserting CRD into the Helm templates")
+	log.Printf("Inserting CRDs Helm templates")
 	if err := generate(repoRoot); err != nil {
-		log.Fatalf("error adding Connector CRD to Helm templates: %v", err)
+		log.Fatalf("error adding CRDs to Helm templates: %v", err)
 	}
 	defer func() {
 		if err := cleanup(repoRoot); err != nil {
@@ -106,34 +110,54 @@ func main() {
 	}
 }
 
+// generate places tailscale.com CRDs (currently Connector, ProxyClass and DNSConfig) into
+// the Helm chart templates behind .Values.installCRDs=true condition (true by
+// default).
 func generate(baseDir string) error {
-	log.Print("Placing Connector CRD into Helm templates..")
-	chartBytes, err := os.ReadFile(filepath.Join(baseDir, crdPath))
-	if err != nil {
-		return fmt.Errorf("error reading CRD contents: %w", err)
+	addCRDToHelm := func(crdPath, crdTemplatePath string) error {
+		chartBytes, err := os.ReadFile(filepath.Join(baseDir, crdPath))
+		if err != nil {
+			return fmt.Errorf("error reading CRD contents: %w", err)
+		}
+		// Place a new temporary Helm template file with the templated CRD
+		// contents into Helm templates.
+		file, err := os.Create(filepath.Join(baseDir, crdTemplatePath))
+		if err != nil {
+			return fmt.Errorf("error creating CRD template file: %w", err)
+		}
+		if _, err := file.Write([]byte(helmConditionalStart)); err != nil {
+			return fmt.Errorf("error writing helm if statement start: %w", err)
+		}
+		if _, err := file.Write(chartBytes); err != nil {
+			return fmt.Errorf("error writing chart bytes: %w", err)
+		}
+		if _, err := file.Write([]byte(helmConditionalEnd)); err != nil {
+			return fmt.Errorf("error writing helm if-statement end: %w", err)
+		}
+		return nil
 	}
-	// Place a new temporary Helm template file with the templated CRD
-	// contents into Helm templates.
-	file, err := os.Create(filepath.Join(baseDir, crdTemplatePath))
-	if err != nil {
-		return fmt.Errorf("error creating CRD template file: %w", err)
+	if err := addCRDToHelm(connectorCRDPath, connectorCRDHelmTemplatePath); err != nil {
+		return fmt.Errorf("error adding Connector CRD to Helm templates: %w", err)
 	}
-	if _, err := file.Write([]byte(helmConditionalStart)); err != nil {
-		return fmt.Errorf("error writing helm if statement start: %w", err)
+	if err := addCRDToHelm(proxyClassCRDPath, proxyClassCRDHelmTemplatePath); err != nil {
+		return fmt.Errorf("error adding ProxyClass CRD to Helm templates: %w", err)
 	}
-	if _, err := file.Write(chartBytes); err != nil {
-		return fmt.Errorf("error writing chart bytes: %w", err)
-	}
-	if _, err := file.Write([]byte(helmConditionalEnd)); err != nil {
-		return fmt.Errorf("error writing helm if-statement end: %w", err)
+	if err := addCRDToHelm(dnsConfigCRDPath, dnsConfigCRDHelmTemplatePath); err != nil {
+		return fmt.Errorf("error adding DNSConfig CRD to Helm templates: %w", err)
 	}
 	return nil
 }
 
 func cleanup(baseDir string) error {
 	log.Print("Cleaning up CRD from Helm templates")
-	if err := os.Remove(filepath.Join(baseDir, crdTemplatePath)); err != nil && !os.IsNotExist(err) {
-		return fmt.Errorf("error cleaning up CRD template: %w", err)
+	if err := os.Remove(filepath.Join(baseDir, connectorCRDHelmTemplatePath)); err != nil && !os.IsNotExist(err) {
+		return fmt.Errorf("error cleaning up Connector CRD template: %w", err)
+	}
+	if err := os.Remove(filepath.Join(baseDir, proxyClassCRDHelmTemplatePath)); err != nil && !os.IsNotExist(err) {
+		return fmt.Errorf("error cleaning up ProxyClass CRD template: %w", err)
+	}
+	if err := os.Remove(filepath.Join(baseDir, dnsConfigCRDHelmTemplatePath)); err != nil && !os.IsNotExist(err) {
+		return fmt.Errorf("error cleaning up DNSConfig CRD template: %w", err)
 	}
 	return nil
 }

cmd/k8s-operator/generate/main_test.go

@@ -42,7 +42,7 @@ func Test_generate(t *testing.T) {
 		t.Fatalf("Helm chart linter failed: %v", err)
 	}
 
-	// Test that default Helm install contains the CRD
+	// Test that default Helm install contains the Connector and ProxyClass CRDs.
 	installContentsWithCRD := bytes.NewBuffer([]byte{})
 	helmTemplateWithCRDCmd := exec.Command(helmCLIPath, "template", helmPackagePath)
 	helmTemplateWithCRDCmd.Stderr = os.Stderr
@@ -51,10 +51,16 @@ func Test_generate(t *testing.T) {
 		t.Fatalf("templating Helm chart with CRDs failed: %v", err)
 	}
 	if !strings.Contains(installContentsWithCRD.String(), "name: connectors.tailscale.com") {
-		t.Errorf("CRD not found in default chart install")
+		t.Errorf("Connector CRD not found in default chart install")
+	}
+	if !strings.Contains(installContentsWithCRD.String(), "name: proxyclasses.tailscale.com") {
+		t.Errorf("ProxyClass CRD not found in default chart install")
+	}
+	if !strings.Contains(installContentsWithCRD.String(), "name: dnsconfigs.tailscale.com") {
+		t.Errorf("DNSConfig CRD not found in default chart install")
 	}
 
-	// Test that CRD can be excluded from Helm chart install
+	// Test that CRDs can be excluded from Helm chart install
 	installContentsWithoutCRD := bytes.NewBuffer([]byte{})
 	helmTemplateWithoutCRDCmd := exec.Command(helmCLIPath, "template", helmPackagePath, "--set", "installCRDs=false")
 	helmTemplateWithoutCRDCmd.Stderr = os.Stderr
@@ -63,6 +69,12 @@ func Test_generate(t *testing.T) {
 		t.Fatalf("templating Helm chart without CRDs failed: %v", err)
 	}
 	if strings.Contains(installContentsWithoutCRD.String(), "name: connectors.tailscale.com") {
-		t.Errorf("CRD found in chart install that should not contain a CRD")
+		t.Errorf("Connector CRD found in chart install that should not contain a CRD")
+	}
+	if strings.Contains(installContentsWithoutCRD.String(), "name: connectors.tailscale.com") {
+		t.Errorf("ProxyClass CRD found in chart install that should not contain a CRD")
+	}
+	if strings.Contains(installContentsWithoutCRD.String(), "name: dnsconfigs.tailscale.com") {
+		t.Errorf("DNSConfig CRD found in chart install that should not contain a CRD")
 	}
 }

cmd/k8s-operator/ingress.go

@@ -132,6 +132,17 @@ func (a *IngressReconciler) maybeProvision(ctx context.Context, logger *zap.Suga
 			return fmt.Errorf("failed to add finalizer: %w", err)
 		}
 	}
+
+	proxyClass := proxyClassForObject(ing)
+	if proxyClass != "" {
+		if ready, err := proxyClassIsReady(ctx, proxyClass, a.Client); err != nil {
+			return fmt.Errorf("error verifying ProxyClass for Ingress: %w", err)
+		} else if !ready {
+			logger.Infof("ProxyClass %s specified for the Ingress, but is not (yet) Ready, waiting..", proxyClass)
+			return nil
+		}
+	}
+
 	a.mu.Lock()
 	a.managedIngresses.Add(ing.UID)
 	gaugeIngressResources.Set(int64(a.managedIngresses.Len()))
@@ -230,6 +241,12 @@ func (a *IngressReconciler) maybeProvision(ctx context.Context, logger *zap.Suga
 		}
 	}
 
+	if len(web.Handlers) == 0 {
+		logger.Warn("Ingress contains no valid backends")
+		a.recorder.Eventf(ing, corev1.EventTypeWarning, "NoValidBackends", "no valid backends")
+		return nil
+	}
+
 	crl := childResourceLabels(ing.Name, ing.Namespace, "ingress")
 	var tags []string
 	if tstr, ok := ing.Annotations[AnnotationTags]; ok {
@@ -247,6 +264,11 @@ func (a *IngressReconciler) maybeProvision(ctx context.Context, logger *zap.Suga
 		ServeConfig:         sc,
 		Tags:                tags,
 		ChildResourceLabels: crl,
+		ProxyClass:          proxyClass,
+	}
+
+	if val := ing.GetAnnotations()[AnnotationExperimentalForwardClusterTrafficViaL7IngresProxy]; val == "true" {
+		sts.ForwardClusterTrafficViaL7IngressProxy = true
 	}
 
 	if _, err := a.ssr.Provision(ctx, logger, sts); err != nil {

cmd/k8s-operator/ingress_test.go

@@ -0,0 +1,270 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !plan9
+
+package main
+
+import (
+	"testing"
+
+	"go.uber.org/zap"
+	appsv1 "k8s.io/api/apps/v1"
+	corev1 "k8s.io/api/core/v1"
+	networkingv1 "k8s.io/api/networking/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"sigs.k8s.io/controller-runtime/pkg/client/fake"
+	"tailscale.com/ipn"
+	tsapi "tailscale.com/k8s-operator/apis/v1alpha1"
+	"tailscale.com/types/ptr"
+	"tailscale.com/util/mak"
+)
+
+func TestTailscaleIngress(t *testing.T) {
+	tsIngressClass := &networkingv1.IngressClass{ObjectMeta: metav1.ObjectMeta{Name: "tailscale"}, Spec: networkingv1.IngressClassSpec{Controller: "tailscale.com/ts-ingress"}}
+	fc := fake.NewFakeClient(tsIngressClass)
+	ft := &fakeTSClient{}
+	fakeTsnetServer := &fakeTSNetServer{certDomains: []string{"foo.com"}}
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+	ingR := &IngressReconciler{
+		Client: fc,
+		ssr: &tailscaleSTSReconciler{
+			Client:            fc,
+			tsClient:          ft,
+			tsnetServer:       fakeTsnetServer,
+			defaultTags:       []string{"tag:k8s"},
+			operatorNamespace: "operator-ns",
+			proxyImage:        "tailscale/tailscale",
+		},
+		logger: zl.Sugar(),
+	}
+
+	// 1. Resources get created for regular Ingress
+	ing := &networkingv1.Ingress{
+		TypeMeta: metav1.TypeMeta{Kind: "Ingress", APIVersion: "networking.k8s.io/v1"},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: "default",
+			// The apiserver is supposed to set the UID, but the fake client
+			// doesn't. So, set it explicitly because other code later depends
+			// on it being set.
+			UID: types.UID("1234-UID"),
+		},
+		Spec: networkingv1.IngressSpec{
+			IngressClassName: ptr.To("tailscale"),
+			DefaultBackend: &networkingv1.IngressBackend{
+				Service: &networkingv1.IngressServiceBackend{
+					Name: "test",
+					Port: networkingv1.ServiceBackendPort{
+						Number: 8080,
+					},
+				},
+			},
+			TLS: []networkingv1.IngressTLS{
+				{Hosts: []string{"default-test"}},
+			},
+		},
+	}
+	mustCreate(t, fc, ing)
+	mustCreate(t, fc, &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: "default",
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP: "1.2.3.4",
+			Ports: []corev1.ServicePort{{
+				Port: 8080,
+				Name: "http"},
+			},
+		},
+	})
+
+	expectReconciled(t, ingR, "default", "test")
+
+	fullName, shortName := findGenName(t, fc, "default", "test", "ingress")
+	opts := configOpts{
+		stsName:    shortName,
+		secretName: fullName,
+		namespace:  "default",
+		parentType: "ingress",
+		hostname:   "default-test",
+	}
+	serveConfig := &ipn.ServeConfig{
+		TCP: map[uint16]*ipn.TCPPortHandler{443: {HTTPS: true}},
+		Web: map[ipn.HostPort]*ipn.WebServerConfig{"${TS_CERT_DOMAIN}:443": {Handlers: map[string]*ipn.HTTPHandler{"/": {Proxy: "http://1.2.3.4:8080/"}}}},
+	}
+	opts.serveConfig = serveConfig
+
+	expectEqual(t, fc, expectedSecret(t, opts), nil)
+	expectEqual(t, fc, expectedHeadlessService(shortName, "ingress"), nil)
+	expectEqual(t, fc, expectedSTSUserspace(t, fc, opts), removeHashAnnotation)
+
+	// 2. Ingress status gets updated with ingress proxy's MagicDNS name
+	// once that becomes available.
+	mustUpdate(t, fc, "operator-ns", opts.secretName, func(secret *corev1.Secret) {
+		mak.Set(&secret.Data, "device_id", []byte("1234"))
+		mak.Set(&secret.Data, "device_fqdn", []byte("foo.tailnetxyz.ts.net"))
+	})
+	expectReconciled(t, ingR, "default", "test")
+	ing.Finalizers = append(ing.Finalizers, "tailscale.com/finalizer")
+	ing.Status.LoadBalancer = networkingv1.IngressLoadBalancerStatus{
+		Ingress: []networkingv1.IngressLoadBalancerIngress{
+			{Hostname: "foo.tailnetxyz.ts.net", Ports: []networkingv1.IngressPortStatus{{Port: 443, Protocol: "TCP"}}},
+		},
+	}
+	expectEqual(t, fc, ing, nil)
+
+	// 3. Resources get created for Ingress that should allow forwarding
+	// cluster traffic
+	mustUpdate(t, fc, "default", "test", func(ing *networkingv1.Ingress) {
+		mak.Set(&ing.ObjectMeta.Annotations, AnnotationExperimentalForwardClusterTrafficViaL7IngresProxy, "true")
+	})
+	opts.shouldEnableForwardingClusterTrafficViaIngress = true
+	expectReconciled(t, ingR, "default", "test")
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
+
+	// 4. Resources get cleaned up when Ingress class is unset
+	mustUpdate(t, fc, "default", "test", func(ing *networkingv1.Ingress) {
+		ing.Spec.IngressClassName = ptr.To("nginx")
+	})
+	expectReconciled(t, ingR, "default", "test")
+	expectReconciled(t, ingR, "default", "test") // deleting Ingress STS requires two reconciles
+	expectMissing[appsv1.StatefulSet](t, fc, "operator-ns", shortName)
+	expectMissing[corev1.Service](t, fc, "operator-ns", shortName)
+	expectMissing[corev1.Secret](t, fc, "operator-ns", fullName)
+}
+
+func TestTailscaleIngressWithProxyClass(t *testing.T) {
+	// Setup
+	pc := &tsapi.ProxyClass{
+		ObjectMeta: metav1.ObjectMeta{Name: "custom-metadata"},
+		Spec: tsapi.ProxyClassSpec{StatefulSet: &tsapi.StatefulSet{
+			Labels:      map[string]string{"foo": "bar"},
+			Annotations: map[string]string{"bar.io/foo": "some-val"},
+			Pod:         &tsapi.Pod{Annotations: map[string]string{"foo.io/bar": "some-val"}}}},
+	}
+	tsIngressClass := &networkingv1.IngressClass{ObjectMeta: metav1.ObjectMeta{Name: "tailscale"}, Spec: networkingv1.IngressClassSpec{Controller: "tailscale.com/ts-ingress"}}
+	fc := fake.NewClientBuilder().
+		WithScheme(tsapi.GlobalScheme).
+		WithObjects(pc, tsIngressClass).
+		WithStatusSubresource(pc).
+		Build()
+	ft := &fakeTSClient{}
+	fakeTsnetServer := &fakeTSNetServer{certDomains: []string{"foo.com"}}
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+	ingR := &IngressReconciler{
+		Client: fc,
+		ssr: &tailscaleSTSReconciler{
+			Client:            fc,
+			tsClient:          ft,
+			tsnetServer:       fakeTsnetServer,
+			defaultTags:       []string{"tag:k8s"},
+			operatorNamespace: "operator-ns",
+			proxyImage:        "tailscale/tailscale",
+		},
+		logger: zl.Sugar(),
+	}
+
+	// 1. Ingress is created with no ProxyClass specified, default proxy
+	// resources get configured.
+	ing := &networkingv1.Ingress{
+		TypeMeta: metav1.TypeMeta{Kind: "Ingress", APIVersion: "networking.k8s.io/v1"},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: "default",
+			// The apiserver is supposed to set the UID, but the fake client
+			// doesn't. So, set it explicitly because other code later depends
+			// on it being set.
+			UID: types.UID("1234-UID"),
+		},
+		Spec: networkingv1.IngressSpec{
+			IngressClassName: ptr.To("tailscale"),
+			DefaultBackend: &networkingv1.IngressBackend{
+				Service: &networkingv1.IngressServiceBackend{
+					Name: "test",
+					Port: networkingv1.ServiceBackendPort{
+						Number: 8080,
+					},
+				},
+			},
+			TLS: []networkingv1.IngressTLS{
+				{Hosts: []string{"default-test"}},
+			},
+		},
+	}
+	mustCreate(t, fc, ing)
+	mustCreate(t, fc, &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: "default",
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP: "1.2.3.4",
+			Ports: []corev1.ServicePort{{
+				Port: 8080,
+				Name: "http"},
+			},
+		},
+	})
+
+	expectReconciled(t, ingR, "default", "test")
+
+	fullName, shortName := findGenName(t, fc, "default", "test", "ingress")
+	opts := configOpts{
+		stsName:    shortName,
+		secretName: fullName,
+		namespace:  "default",
+		parentType: "ingress",
+		hostname:   "default-test",
+	}
+	serveConfig := &ipn.ServeConfig{
+		TCP: map[uint16]*ipn.TCPPortHandler{443: {HTTPS: true}},
+		Web: map[ipn.HostPort]*ipn.WebServerConfig{"${TS_CERT_DOMAIN}:443": {Handlers: map[string]*ipn.HTTPHandler{"/": {Proxy: "http://1.2.3.4:8080/"}}}},
+	}
+	opts.serveConfig = serveConfig
+
+	expectEqual(t, fc, expectedSecret(t, opts), nil)
+	expectEqual(t, fc, expectedHeadlessService(shortName, "ingress"), nil)
+	expectEqual(t, fc, expectedSTSUserspace(t, fc, opts), removeHashAnnotation)
+
+	// 2. Ingress is updated to specify a ProxyClass, ProxyClass is not yet
+	// ready, so proxy resource configuration does not change.
+	mustUpdate(t, fc, "default", "test", func(ing *networkingv1.Ingress) {
+		mak.Set(&ing.ObjectMeta.Labels, LabelProxyClass, "custom-metadata")
+	})
+	expectReconciled(t, ingR, "default", "test")
+	expectEqual(t, fc, expectedSTSUserspace(t, fc, opts), removeHashAnnotation)
+
+	// 3. ProxyClass is set to Ready by proxy-class reconciler. Ingress get
+	// reconciled and configuration from the ProxyClass is applied to the
+	// created proxy resources.
+	mustUpdateStatus(t, fc, "", "custom-metadata", func(pc *tsapi.ProxyClass) {
+		pc.Status = tsapi.ProxyClassStatus{
+			Conditions: []tsapi.ConnectorCondition{{
+				Status:             metav1.ConditionTrue,
+				Type:               tsapi.ProxyClassready,
+				ObservedGeneration: pc.Generation,
+			}}}
+	})
+	expectReconciled(t, ingR, "default", "test")
+	opts.proxyClass = pc.Name
+	expectEqual(t, fc, expectedSTSUserspace(t, fc, opts), removeHashAnnotation)
+
+	// 4. tailscale.com/proxy-class label is removed from the Ingress, the
+	// Ingress gets reconciled and the custom ProxyClass configuration is
+	// removed from the proxy resources.
+	mustUpdate(t, fc, "default", "test", func(ing *networkingv1.Ingress) {
+		delete(ing.ObjectMeta.Labels, LabelProxyClass)
+	})
+	expectReconciled(t, ingR, "default", "test")
+	opts.proxyClass = ""
+	expectEqual(t, fc, expectedSTSUserspace(t, fc, opts), removeHashAnnotation)
+}

cmd/k8s-operator/nameserver.go

@@ -0,0 +1,283 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !plan9
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"slices"
+	"sync"
+
+	_ "embed"
+
+	"github.com/pkg/errors"
+	"go.uber.org/zap"
+	xslices "golang.org/x/exp/slices"
+	appsv1 "k8s.io/api/apps/v1"
+	corev1 "k8s.io/api/core/v1"
+	apiequality "k8s.io/apimachinery/pkg/api/equality"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/client-go/tools/record"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/reconcile"
+	"sigs.k8s.io/yaml"
+	tsoperator "tailscale.com/k8s-operator"
+	tsapi "tailscale.com/k8s-operator/apis/v1alpha1"
+	"tailscale.com/tstime"
+	"tailscale.com/util/clientmetric"
+	"tailscale.com/util/set"
+)
+
+const (
+	reasonNameserverCreationFailed  = "NameserverCreationFailed"
+	reasonMultipleDNSConfigsPresent = "MultipleDNSConfigsPresent"
+
+	reasonNameserverCreated = "NameserverCreated"
+
+	messageNameserverCreationFailed  = "Failed creating nameserver resources: %v"
+	messageMultipleDNSConfigsPresent = "Multiple DNSConfig resources found in cluster. Please ensure no more than one is present."
+
+	defaultNameserverImageRepo = "tailscale/k8s-nameserver"
+	// TODO (irbekrm): once we start publishing nameserver images for stable
+	// track, replace 'unstable' here with the version of this operator
+	// instance.
+	defaultNameserverImageTag = "unstable"
+)
+
+// NameserverReconciler knows how to create nameserver resources in cluster in
+// response to users applying DNSConfig.
+type NameserverReconciler struct {
+	client.Client
+	logger      *zap.SugaredLogger
+	recorder    record.EventRecorder
+	clock       tstime.Clock
+	tsNamespace string
+
+	mu                 sync.Mutex           // protects following
+	managedNameservers set.Slice[types.UID] // one or none
+}
+
+var (
+	gaugeNameserverResources = clientmetric.NewGauge("k8s_nameserver_resources")
+)
+
+func (a *NameserverReconciler) Reconcile(ctx context.Context, req reconcile.Request) (res reconcile.Result, err error) {
+	logger := a.logger.With("dnsConfig", req.Name)
+	logger.Debugf("starting reconcile")
+	defer logger.Debugf("reconcile finished")
+
+	var dnsCfg tsapi.DNSConfig
+	err = a.Get(ctx, req.NamespacedName, &dnsCfg)
+	if apierrors.IsNotFound(err) {
+		// Request object not found, could have been deleted after reconcile request.
+		logger.Debugf("dnsconfig not found, assuming it was deleted")
+		return reconcile.Result{}, nil
+	} else if err != nil {
+		return reconcile.Result{}, fmt.Errorf("failed to get dnsconfig: %w", err)
+	}
+	if !dnsCfg.DeletionTimestamp.IsZero() {
+		ix := xslices.Index(dnsCfg.Finalizers, FinalizerName)
+		if ix < 0 {
+			logger.Debugf("no finalizer, nothing to do")
+			return reconcile.Result{}, nil
+		}
+		logger.Info("Cleaning up DNSConfig resources")
+		if err := a.maybeCleanup(ctx, &dnsCfg, logger); err != nil {
+			logger.Errorf("error cleaning up reconciler resource: %v", err)
+			return res, err
+		}
+		dnsCfg.Finalizers = append(dnsCfg.Finalizers[:ix], dnsCfg.Finalizers[ix+1:]...)
+		if err := a.Update(ctx, &dnsCfg); err != nil {
+			logger.Errorf("error removing finalizer: %v", err)
+			return reconcile.Result{}, err
+		}
+		logger.Infof("Nameserver resources cleaned up")
+		return reconcile.Result{}, nil
+	}
+
+	oldCnStatus := dnsCfg.Status.DeepCopy()
+	setStatus := func(dnsCfg *tsapi.DNSConfig, conditionType tsapi.ConnectorConditionType, status metav1.ConditionStatus, reason, message string) (reconcile.Result, error) {
+		tsoperator.SetDNSConfigCondition(dnsCfg, tsapi.NameserverReady, status, reason, message, dnsCfg.Generation, a.clock, logger)
+		if !apiequality.Semantic.DeepEqual(oldCnStatus, dnsCfg.Status) {
+			// An error encountered here should get returned by the Reconcile function.
+			if updateErr := a.Client.Status().Update(ctx, dnsCfg); updateErr != nil {
+				err = errors.Wrap(err, updateErr.Error())
+			}
+		}
+		return res, err
+	}
+	var dnsCfgs tsapi.DNSConfigList
+	if err := a.List(ctx, &dnsCfgs); err != nil {
+		return res, fmt.Errorf("error listing DNSConfigs: %w", err)
+	}
+	if len(dnsCfgs.Items) > 1 { // enforce DNSConfig to be a singleton
+		msg := "invalid cluster configuration: more than one tailscale.com/dnsconfigs found. Please ensure that no more than one is created."
+		logger.Error(msg)
+		a.recorder.Event(&dnsCfg, corev1.EventTypeWarning, reasonMultipleDNSConfigsPresent, messageMultipleDNSConfigsPresent)
+		setStatus(&dnsCfg, tsapi.NameserverReady, metav1.ConditionFalse, reasonMultipleDNSConfigsPresent, messageMultipleDNSConfigsPresent)
+	}
+
+	if !slices.Contains(dnsCfg.Finalizers, FinalizerName) {
+		logger.Infof("ensuring nameserver resources")
+		dnsCfg.Finalizers = append(dnsCfg.Finalizers, FinalizerName)
+		if err := a.Update(ctx, &dnsCfg); err != nil {
+			msg := fmt.Sprintf(messageNameserverCreationFailed, err)
+			logger.Error(msg)
+			return setStatus(&dnsCfg, tsapi.NameserverReady, metav1.ConditionFalse, reasonNameserverCreationFailed, msg)
+		}
+	}
+	if err := a.maybeProvision(ctx, &dnsCfg, logger); err != nil {
+		return reconcile.Result{}, fmt.Errorf("error provisioning nameserver resources: %w", err)
+	}
+
+	a.mu.Lock()
+	a.managedNameservers.Add(dnsCfg.UID)
+	a.mu.Unlock()
+	gaugeNameserverResources.Set(int64(a.managedNameservers.Len()))
+
+	svc := &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{Name: "nameserver", Namespace: a.tsNamespace},
+	}
+	if err := a.Client.Get(ctx, client.ObjectKeyFromObject(svc), svc); err != nil {
+		return res, fmt.Errorf("error getting Service: %w", err)
+	}
+	if ip := svc.Spec.ClusterIP; ip != "" && ip != "None" {
+		dnsCfg.Status.Nameserver = &tsapi.NameserverStatus{
+			IP: ip,
+		}
+		return setStatus(&dnsCfg, tsapi.NameserverReady, metav1.ConditionTrue, reasonNameserverCreated, reasonNameserverCreated)
+	}
+	logger.Info("nameserver Service does not have an IP address allocated, waiting...")
+	return reconcile.Result{}, nil
+}
+
+func nameserverResourceLabels(name, namespace string) map[string]string {
+	labels := childResourceLabels(name, namespace, "nameserver")
+	labels["app.kubernetes.io/name"] = "tailscale"
+	labels["app.kubernetes.io/component"] = "nameserver"
+	return labels
+}
+
+func (a *NameserverReconciler) maybeProvision(ctx context.Context, tsDNSCfg *tsapi.DNSConfig, logger *zap.SugaredLogger) error {
+	labels := nameserverResourceLabels(tsDNSCfg.Name, a.tsNamespace)
+	dCfg := &deployConfig{
+		ownerRefs: []metav1.OwnerReference{*metav1.NewControllerRef(tsDNSCfg, tsapi.SchemeGroupVersion.WithKind("DNSConfig"))},
+		namespace: a.tsNamespace,
+		labels:    labels,
+		imageRepo: defaultNameserverImageRepo,
+		imageTag:  defaultNameserverImageTag,
+	}
+	if tsDNSCfg.Spec.Nameserver.Image != nil && tsDNSCfg.Spec.Nameserver.Image.Repo != "" {
+		dCfg.imageRepo = tsDNSCfg.Spec.Nameserver.Image.Repo
+	}
+	if tsDNSCfg.Spec.Nameserver.Image != nil && tsDNSCfg.Spec.Nameserver.Image.Tag != "" {
+		dCfg.imageTag = tsDNSCfg.Spec.Nameserver.Image.Tag
+	}
+	for _, deployable := range []deployable{saDeployable, deployDeployable, svcDeployable, cmDeployable} {
+		if err := deployable.updateObj(ctx, dCfg, a.Client); err != nil {
+			return fmt.Errorf("error reconciling %s: %w", deployable.kind, err)
+		}
+	}
+	return nil
+}
+
+// maybeCleanup removes DNSConfig from being tracked. The cluster resources
+// created, will be automatically garbage collected as they are owned by the
+// DNSConfig.
+func (a *NameserverReconciler) maybeCleanup(ctx context.Context, dnsCfg *tsapi.DNSConfig, logger *zap.SugaredLogger) error {
+	a.mu.Lock()
+	a.managedNameservers.Remove(dnsCfg.UID)
+	a.mu.Unlock()
+	gaugeNameserverResources.Set(int64(a.managedNameservers.Len()))
+	return nil
+}
+
+type deployable struct {
+	kind      string
+	updateObj func(context.Context, *deployConfig, client.Client) error
+}
+
+type deployConfig struct {
+	imageRepo string
+	imageTag  string
+	labels    map[string]string
+	ownerRefs []metav1.OwnerReference
+	namespace string
+}
+
+var (
+	//go:embed deploy/manifests/nameserver/cm.yaml
+	cmYaml []byte
+	//go:embed deploy/manifests/nameserver/deploy.yaml
+	deployYaml []byte
+	//go:embed deploy/manifests/nameserver/sa.yaml
+	saYaml []byte
+	//go:embed deploy/manifests/nameserver/svc.yaml
+	svcYaml []byte
+
+	deployDeployable = deployable{
+		kind: "Deployment",
+		updateObj: func(ctx context.Context, cfg *deployConfig, kubeClient client.Client) error {
+			d := new(appsv1.Deployment)
+			if err := yaml.Unmarshal(deployYaml, &d); err != nil {
+				return fmt.Errorf("error unmarshalling Deployment yaml: %w", err)
+			}
+			d.Spec.Template.Spec.Containers[0].Image = fmt.Sprintf("%s:%s", cfg.imageRepo, cfg.imageTag)
+			d.ObjectMeta.Namespace = cfg.namespace
+			d.ObjectMeta.Labels = cfg.labels
+			d.ObjectMeta.OwnerReferences = cfg.ownerRefs
+			updateF := func(oldD *appsv1.Deployment) {
+				oldD.Spec = d.Spec
+			}
+			_, err := createOrUpdate[appsv1.Deployment](ctx, kubeClient, cfg.namespace, d, updateF)
+			return err
+		},
+	}
+	saDeployable = deployable{
+		kind: "ServiceAccount",
+		updateObj: func(ctx context.Context, cfg *deployConfig, kubeClient client.Client) error {
+			sa := new(corev1.ServiceAccount)
+			if err := yaml.Unmarshal(saYaml, &sa); err != nil {
+				return fmt.Errorf("error unmarshalling ServiceAccount yaml: %w", err)
+			}
+			sa.ObjectMeta.Labels = cfg.labels
+			sa.ObjectMeta.OwnerReferences = cfg.ownerRefs
+			sa.ObjectMeta.Namespace = cfg.namespace
+			_, err := createOrUpdate(ctx, kubeClient, cfg.namespace, sa, func(*corev1.ServiceAccount) {})
+			return err
+		},
+	}
+	svcDeployable = deployable{
+		kind: "Service",
+		updateObj: func(ctx context.Context, cfg *deployConfig, kubeClient client.Client) error {
+			svc := new(corev1.Service)
+			if err := yaml.Unmarshal(svcYaml, &svc); err != nil {
+				return fmt.Errorf("error unmarshalling Service yaml: %w", err)
+			}
+			svc.ObjectMeta.Labels = cfg.labels
+			svc.ObjectMeta.OwnerReferences = cfg.ownerRefs
+			svc.ObjectMeta.Namespace = cfg.namespace
+			_, err := createOrUpdate[corev1.Service](ctx, kubeClient, cfg.namespace, svc, func(*corev1.Service) {})
+			return err
+		},
+	}
+	cmDeployable = deployable{
+		kind: "ConfigMap",
+		updateObj: func(ctx context.Context, cfg *deployConfig, kubeClient client.Client) error {
+			cm := new(corev1.ConfigMap)
+			if err := yaml.Unmarshal(cmYaml, &cm); err != nil {
+				return fmt.Errorf("error unmarshalling ConfigMap yaml: %w", err)
+			}
+			cm.ObjectMeta.Labels = cfg.labels
+			cm.ObjectMeta.OwnerReferences = cfg.ownerRefs
+			cm.ObjectMeta.Namespace = cfg.namespace
+			_, err := createOrUpdate[corev1.ConfigMap](ctx, kubeClient, cfg.namespace, cm, func(cm *corev1.ConfigMap) {})
+			return err
+		},
+	}
+)

cmd/k8s-operator/nameserver_test.go

@@ -0,0 +1,127 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !plan9
+
+// tailscale-operator provides a way to expose services running in a Kubernetes
+// cluster to your Tailnet and to make Tailscale nodes available to cluster
+// workloads
+package main
+
+import (
+	"encoding/json"
+	"testing"
+	"time"
+
+	"go.uber.org/zap"
+	appsv1 "k8s.io/api/apps/v1"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"sigs.k8s.io/controller-runtime/pkg/client/fake"
+	"sigs.k8s.io/yaml"
+	operatorutils "tailscale.com/k8s-operator"
+	tsapi "tailscale.com/k8s-operator/apis/v1alpha1"
+	"tailscale.com/tstest"
+	"tailscale.com/util/mak"
+)
+
+func TestNameserverReconciler(t *testing.T) {
+	dnsCfg := &tsapi.DNSConfig{
+		TypeMeta: metav1.TypeMeta{Kind: "DNSConfig", APIVersion: "tailscale.com/v1alpha1"},
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "test",
+		},
+		Spec: tsapi.DNSConfigSpec{
+			Nameserver: &tsapi.Nameserver{
+				Image: &tsapi.Image{
+					Repo: "test",
+					Tag:  "v0.0.1",
+				},
+			},
+		},
+	}
+
+	fc := fake.NewClientBuilder().
+		WithScheme(tsapi.GlobalScheme).
+		WithObjects(dnsCfg).
+		WithStatusSubresource(dnsCfg).
+		Build()
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+	cl := tstest.NewClock(tstest.ClockOpts{})
+	nr := &NameserverReconciler{
+		Client:      fc,
+		clock:       cl,
+		logger:      zl.Sugar(),
+		tsNamespace: "tailscale",
+	}
+	expectReconciled(t, nr, "", "test")
+	// Verify that nameserver Deployment has been created and has the expected fields.
+	wantsDeploy := &appsv1.Deployment{ObjectMeta: metav1.ObjectMeta{Name: "nameserver", Namespace: "tailscale"}, TypeMeta: metav1.TypeMeta{Kind: "Deployment", APIVersion: appsv1.SchemeGroupVersion.Identifier()}}
+	if err := yaml.Unmarshal(deployYaml, wantsDeploy); err != nil {
+		t.Fatalf("unmarshalling yaml: %v", err)
+	}
+	dnsCfgOwnerRef := metav1.NewControllerRef(dnsCfg, tsapi.SchemeGroupVersion.WithKind("DNSConfig"))
+	wantsDeploy.OwnerReferences = []metav1.OwnerReference{*dnsCfgOwnerRef}
+	wantsDeploy.Spec.Template.Spec.Containers[0].Image = "test:v0.0.1"
+	wantsDeploy.Namespace = "tailscale"
+	labels := nameserverResourceLabels("test", "tailscale")
+	wantsDeploy.ObjectMeta.Labels = labels
+	expectEqual(t, fc, wantsDeploy, nil)
+
+	// Verify that DNSConfig advertizes the nameserver's Service IP address,
+	// has the ready status condition and tailscale finalizer.
+	mustUpdate(t, fc, "tailscale", "nameserver", func(svc *corev1.Service) {
+		svc.Spec.ClusterIP = "1.2.3.4"
+	})
+	expectReconciled(t, nr, "", "test")
+	dnsCfg.Status.Nameserver = &tsapi.NameserverStatus{
+		IP: "1.2.3.4",
+	}
+	dnsCfg.Finalizers = []string{FinalizerName}
+	dnsCfg.Status.Conditions = append(dnsCfg.Status.Conditions, tsapi.ConnectorCondition{
+		Type:               tsapi.NameserverReady,
+		Status:             metav1.ConditionTrue,
+		Reason:             reasonNameserverCreated,
+		Message:            reasonNameserverCreated,
+		LastTransitionTime: &metav1.Time{Time: cl.Now().Truncate(time.Second)},
+	})
+	expectEqual(t, fc, dnsCfg, nil)
+
+	// // Verify that nameserver image gets updated to match DNSConfig spec.
+	mustUpdate(t, fc, "", "test", func(dnsCfg *tsapi.DNSConfig) {
+		dnsCfg.Spec.Nameserver.Image.Tag = "v0.0.2"
+	})
+	expectReconciled(t, nr, "", "test")
+	wantsDeploy.Spec.Template.Spec.Containers[0].Image = "test:v0.0.2"
+	expectEqual(t, fc, wantsDeploy, nil)
+
+	// Verify that when another actor sets ConfigMap data, it does not get
+	// overwritten by nameserver reconciler.
+	dnsRecords := &operatorutils.Records{Version: "v1alpha1", IP4: map[string][]string{"foo.ts.net": {"1.2.3.4"}}}
+	bs, err := json.Marshal(dnsRecords)
+	if err != nil {
+		t.Fatalf("error marshalling ConfigMap contents: %v", err)
+	}
+	mustUpdate(t, fc, "tailscale", "dnsrecords", func(cm *corev1.ConfigMap) {
+		mak.Set(&cm.Data, "records.json", string(bs))
+	})
+	expectReconciled(t, nr, "", "test")
+	wantCm := &corev1.ConfigMap{ObjectMeta: metav1.ObjectMeta{Name: "dnsrecords",
+		Namespace: "tailscale", Labels: labels, OwnerReferences: []metav1.OwnerReference{*dnsCfgOwnerRef}},
+		TypeMeta: metav1.TypeMeta{Kind: "ConfigMap", APIVersion: "v1"},
+		Data:     map[string]string{"records.json": string(bs)},
+	}
+	expectEqual(t, fc, wantCm, nil)
+
+	// Verify that if dnsconfig.spec.nameserver.image.{repo,tag} are unset,
+	// the nameserver image defaults to tailscale/k8s-nameserver:unstable.
+	mustUpdate(t, fc, "", "test", func(dnsCfg *tsapi.DNSConfig) {
+		dnsCfg.Spec.Nameserver.Image = nil
+	})
+	expectReconciled(t, nr, "", "test")
+	wantsDeploy.Spec.Template.Spec.Containers[0].Image = "tailscale/k8s-nameserver:unstable"
+	expectEqual(t, fc, wantsDeploy, nil)
+}

cmd/k8s-operator/operator.go

@@ -20,6 +20,7 @@ import (
 	"golang.org/x/oauth2/clientcredentials"
 	appsv1 "k8s.io/api/apps/v1"
 	corev1 "k8s.io/api/core/v1"
+	discoveryv1 "k8s.io/api/discovery/v1"
 	networkingv1 "k8s.io/api/networking/v1"
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/client-go/rest"
@@ -47,21 +48,25 @@ import (
 // Generate static manifests for deploying Tailscale operator on Kubernetes from the operator's Helm chart.
 //go:generate go run tailscale.com/cmd/k8s-operator/generate staticmanifests
 
-// Generate Connector CustomResourceDefinition yaml from its Go types.
+// Generate Connector and ProxyClass CustomResourceDefinition yamls from their Go types.
 //go:generate go run sigs.k8s.io/controller-tools/cmd/controller-gen crd schemapatch:manifests=./deploy/crds output:dir=./deploy/crds paths=../../k8s-operator/apis/...
 
+// Generate CRD docs from the yamls
+//go:generate go run fybrik.io/crdoc --resources=./deploy/crds --output=../../k8s-operator/api.md
+
 func main() {
 	// Required to use our client API. We're fine with the instability since the
 	// client lives in the same repo as this code.
 	tailscale.I_Acknowledge_This_API_Is_Unstable = true
 
 	var (
-		tsNamespace       = defaultEnv("OPERATOR_NAMESPACE", "")
-		tslogging         = defaultEnv("OPERATOR_LOGGING", "info")
-		image             = defaultEnv("PROXY_IMAGE", "tailscale/tailscale:latest")
-		priorityClassName = defaultEnv("PROXY_PRIORITY_CLASS_NAME", "")
-		tags              = defaultEnv("PROXY_TAGS", "tag:k8s")
-		tsFirewallMode    = defaultEnv("PROXY_FIREWALL_MODE", "")
+		tsNamespace           = defaultEnv("OPERATOR_NAMESPACE", "")
+		tslogging             = defaultEnv("OPERATOR_LOGGING", "info")
+		image                 = defaultEnv("PROXY_IMAGE", "tailscale/tailscale:latest")
+		priorityClassName     = defaultEnv("PROXY_PRIORITY_CLASS_NAME", "")
+		tags                  = defaultEnv("PROXY_TAGS", "tag:k8s")
+		tsFirewallMode        = defaultEnv("PROXY_FIREWALL_MODE", "")
+		isDefaultLoadBalancer = defaultBool("OPERATOR_DEFAULT_LOAD_BALANCER", false)
 	)
 
 	var opts []kzap.Opts
@@ -90,9 +95,19 @@ func main() {
 	defer s.Close()
 	restConfig := config.GetConfigOrDie()
 	maybeLaunchAPIServerProxy(zlog, restConfig, s, mode)
-	// TODO (irbekrm): gather the reconciler options into an opts struct
-	// rather than passing a million of them in one by one.
-	runReconcilers(zlog, s, tsNamespace, restConfig, tsClient, image, priorityClassName, tags, tsFirewallMode)
+	rOpts := reconcilerOpts{
+		log:                           zlog,
+		tsServer:                      s,
+		tsClient:                      tsClient,
+		tailscaleNamespace:            tsNamespace,
+		restConfig:                    restConfig,
+		proxyImage:                    image,
+		proxyPriorityClassName:        priorityClassName,
+		proxyActAsDefaultLoadBalancer: isDefaultLoadBalancer,
+		proxyTags:                     tags,
+		proxyFirewallMode:             tsFirewallMode,
+	}
+	runReconcilers(rOpts)
 }
 
 // initTSNet initializes the tsnet.Server and logs in to Tailscale. It uses the
@@ -200,11 +215,8 @@ waitOnline:
 
 // runReconcilers starts the controller-runtime manager and registers the
 // ServiceReconciler. It blocks forever.
-func runReconcilers(zlog *zap.SugaredLogger, s *tsnet.Server, tsNamespace string, restConfig *rest.Config, tsClient *tailscale.Client, image, priorityClassName, tags, tsFirewallMode string) {
-	var (
-		isDefaultLoadBalancer = defaultBool("OPERATOR_DEFAULT_LOAD_BALANCER", false)
-	)
-	startlog := zlog.Named("startReconcilers")
+func runReconcilers(opts reconcilerOpts) {
+	startlog := opts.log.Named("startReconcilers")
 	// For secrets and statefulsets, we only get permission to touch the objects
 	// in the controller's own namespace. This cannot be expressed by
 	// .Watches(...) below, instead you have to add a per-type field selector to
@@ -212,7 +224,7 @@ func runReconcilers(zlog *zap.SugaredLogger, s *tsnet.Server, tsNamespace string
 	// implicitly filter what parts of the world the builder code gets to see at
 	// all.
 	nsFilter := cache.ByObject{
-		Field: client.InNamespace(tsNamespace).AsSelector(),
+		Field: client.InNamespace(opts.tailscaleNamespace).AsSelector(),
 	}
 	mgrOpts := manager.Options{
 		// TODO (irbekrm): stricter filtering what we watch/cache/call
@@ -220,30 +232,37 @@ func runReconcilers(zlog *zap.SugaredLogger, s *tsnet.Server, tsNamespace string
 		// resources that we GET via the controller manager's client.
 		Cache: cache.Options{
 			ByObject: map[client.Object]cache.ByObject{
-				&corev1.Secret{}:      nsFilter,
-				&appsv1.StatefulSet{}: nsFilter,
+				&corev1.Secret{}:             nsFilter,
+				&corev1.ServiceAccount{}:     nsFilter,
+				&corev1.ConfigMap{}:          nsFilter,
+				&appsv1.StatefulSet{}:        nsFilter,
+				&appsv1.Deployment{}:         nsFilter,
+				&discoveryv1.EndpointSlice{}: nsFilter,
 			},
 		},
 		Scheme: tsapi.GlobalScheme,
 	}
-	mgr, err := manager.New(restConfig, mgrOpts)
+	mgr, err := manager.New(opts.restConfig, mgrOpts)
 	if err != nil {
 		startlog.Fatalf("could not create manager: %v", err)
 	}
 
 	svcFilter := handler.EnqueueRequestsFromMapFunc(serviceHandler)
 	svcChildFilter := handler.EnqueueRequestsFromMapFunc(managedResourceHandlerForType("svc"))
+	// If a ProxyClass changes, enqueue all Services labeled with that
+	// ProxyClass's name.
+	proxyClassFilterForSvc := handler.EnqueueRequestsFromMapFunc(proxyClassHandlerForSvc(mgr.GetClient(), startlog))
 
 	eventRecorder := mgr.GetEventRecorderFor("tailscale-operator")
 	ssr := &tailscaleSTSReconciler{
 		Client:                 mgr.GetClient(),
-		tsnetServer:            s,
-		tsClient:               tsClient,
-		defaultTags:            strings.Split(tags, ","),
-		operatorNamespace:      tsNamespace,
-		proxyImage:             image,
-		proxyPriorityClassName: priorityClassName,
-		tsFirewallMode:         tsFirewallMode,
+		tsnetServer:            opts.tsServer,
+		tsClient:               opts.tsClient,
+		defaultTags:            strings.Split(opts.proxyTags, ","),
+		operatorNamespace:      opts.tailscaleNamespace,
+		proxyImage:             opts.proxyImage,
+		proxyPriorityClassName: opts.proxyPriorityClassName,
+		tsFirewallMode:         opts.proxyFirewallMode,
 	}
 	err = builder.
 		ControllerManagedBy(mgr).
@@ -251,47 +270,118 @@ func runReconcilers(zlog *zap.SugaredLogger, s *tsnet.Server, tsNamespace string
 		Watches(&corev1.Service{}, svcFilter).
 		Watches(&appsv1.StatefulSet{}, svcChildFilter).
 		Watches(&corev1.Secret{}, svcChildFilter).
+		Watches(&tsapi.ProxyClass{}, proxyClassFilterForSvc).
 		Complete(&ServiceReconciler{
 			ssr:                   ssr,
 			Client:                mgr.GetClient(),
-			logger:                zlog.Named("service-reconciler"),
-			isDefaultLoadBalancer: isDefaultLoadBalancer,
+			logger:                opts.log.Named("service-reconciler"),
+			isDefaultLoadBalancer: opts.proxyActAsDefaultLoadBalancer,
 			recorder:              eventRecorder,
+			tsNamespace:           opts.tailscaleNamespace,
 		})
 	if err != nil {
-		startlog.Fatalf("could not create controller: %v", err)
+		startlog.Fatalf("could not create service reconciler: %v", err)
 	}
 	ingressChildFilter := handler.EnqueueRequestsFromMapFunc(managedResourceHandlerForType("ingress"))
+	// If a ProxyClassChanges, enqueue all Ingresses labeled with that
+	// ProxyClass's name.
+	proxyClassFilterForIngress := handler.EnqueueRequestsFromMapFunc(proxyClassHandlerForIngress(mgr.GetClient(), startlog))
+	// Enque Ingress if a managed Service or backend Service associated with a tailscale Ingress changes.
+	svcHandlerForIngress := handler.EnqueueRequestsFromMapFunc(serviceHandlerForIngress(mgr.GetClient(), startlog))
 	err = builder.
 		ControllerManagedBy(mgr).
 		For(&networkingv1.Ingress{}).
 		Watches(&appsv1.StatefulSet{}, ingressChildFilter).
 		Watches(&corev1.Secret{}, ingressChildFilter).
-		Watches(&corev1.Service{}, ingressChildFilter).
+		Watches(&corev1.Service{}, svcHandlerForIngress).
+		Watches(&tsapi.ProxyClass{}, proxyClassFilterForIngress).
 		Complete(&IngressReconciler{
 			ssr:      ssr,
 			recorder: eventRecorder,
 			Client:   mgr.GetClient(),
-			logger:   zlog.Named("ingress-reconciler"),
+			logger:   opts.log.Named("ingress-reconciler"),
 		})
 	if err != nil {
-		startlog.Fatalf("could not create controller: %v", err)
+		startlog.Fatalf("could not create ingress reconciler: %v", err)
 	}
 
 	connectorFilter := handler.EnqueueRequestsFromMapFunc(managedResourceHandlerForType("connector"))
+	// If a ProxyClassChanges, enqueue all Connectors that have
+	// .spec.proxyClass set to the name of this ProxyClass.
+	proxyClassFilterForConnector := handler.EnqueueRequestsFromMapFunc(proxyClassHandlerForConnector(mgr.GetClient(), startlog))
 	err = builder.ControllerManagedBy(mgr).
 		For(&tsapi.Connector{}).
 		Watches(&appsv1.StatefulSet{}, connectorFilter).
 		Watches(&corev1.Secret{}, connectorFilter).
+		Watches(&tsapi.ProxyClass{}, proxyClassFilterForConnector).
 		Complete(&ConnectorReconciler{
 			ssr:      ssr,
 			recorder: eventRecorder,
 			Client:   mgr.GetClient(),
-			logger:   zlog.Named("connector-reconciler"),
+			logger:   opts.log.Named("connector-reconciler"),
 			clock:    tstime.DefaultClock{},
 		})
 	if err != nil {
-		startlog.Fatal("could not create connector reconciler: %v", err)
+		startlog.Fatalf("could not create connector reconciler: %v", err)
+	}
+	// TODO (irbekrm): switch to metadata-only watches for resources whose
+	// spec we don't need to inspect to reduce memory consumption.
+	// https://github.com/kubernetes-sigs/controller-runtime/issues/1159
+	nameserverFilter := handler.EnqueueRequestsFromMapFunc(managedResourceHandlerForType("nameserver"))
+	err = builder.ControllerManagedBy(mgr).
+		For(&tsapi.DNSConfig{}).
+		Watches(&appsv1.Deployment{}, nameserverFilter).
+		Watches(&corev1.ConfigMap{}, nameserverFilter).
+		Watches(&corev1.Service{}, nameserverFilter).
+		Watches(&corev1.ServiceAccount{}, nameserverFilter).
+		Complete(&NameserverReconciler{
+			recorder:    eventRecorder,
+			tsNamespace: opts.tailscaleNamespace,
+			Client:      mgr.GetClient(),
+			logger:      opts.log.Named("nameserver-reconciler"),
+			clock:       tstime.DefaultClock{},
+		})
+	if err != nil {
+		startlog.Fatalf("could not create nameserver reconciler: %v", err)
+	}
+	err = builder.ControllerManagedBy(mgr).
+		For(&tsapi.ProxyClass{}).
+		Complete(&ProxyClassReconciler{
+			Client:   mgr.GetClient(),
+			recorder: eventRecorder,
+			logger:   opts.log.Named("proxyclass-reconciler"),
+			clock:    tstime.DefaultClock{},
+		})
+	if err != nil {
+		startlog.Fatal("could not create proxyclass reconciler: %v", err)
+	}
+	logger := startlog.Named("dns-records-reconciler-event-handlers")
+	// On EndpointSlice events, if it is an EndpointSlice for an
+	// ingress/egress proxy headless Service, reconcile the headless
+	// Service.
+	dnsRREpsOpts := handler.EnqueueRequestsFromMapFunc(dnsRecordsReconcilerEndpointSliceHandler)
+	// On DNSConfig changes, reconcile all headless Services for
+	// ingress/egress proxies in operator namespace.
+	dnsRRDNSConfigOpts := handler.EnqueueRequestsFromMapFunc(enqueueAllIngressEgressProxySvcsInNS(opts.tailscaleNamespace, mgr.GetClient(), logger))
+	// On Service events, if it is an ingress/egress proxy headless Service, reconcile it.
+	dnsRRServiceOpts := handler.EnqueueRequestsFromMapFunc(dnsRecordsReconcilerServiceHandler)
+	// On Ingress events, if it is a tailscale Ingress or if tailscale is the default ingress controller, reconcile the proxy
+	// headless Service.
+	dnsRRIngressOpts := handler.EnqueueRequestsFromMapFunc(dnsRecordsReconcilerIngressHandler(opts.tailscaleNamespace, opts.proxyActAsDefaultLoadBalancer, mgr.GetClient(), logger))
+	err = builder.ControllerManagedBy(mgr).
+		Named("dns-records-reconciler").
+		Watches(&corev1.Service{}, dnsRRServiceOpts).
+		Watches(&networkingv1.Ingress{}, dnsRRIngressOpts).
+		Watches(&discoveryv1.EndpointSlice{}, dnsRREpsOpts).
+		Watches(&tsapi.DNSConfig{}, dnsRRDNSConfigOpts).
+		Complete(&dnsRecordsReconciler{
+			Client:                mgr.GetClient(),
+			tsNamespace:           opts.tailscaleNamespace,
+			logger:                opts.log.Named("dns-records-reconciler"),
+			isDefaultLoadBalancer: opts.proxyActAsDefaultLoadBalancer,
+		})
+	if err != nil {
+		startlog.Fatalf("could not create DNS records reconciler: %v", err)
 	}
 	startlog.Infof("Startup complete, operator running, version: %s", version.Long())
 	if err := mgr.Start(signals.SetupSignalHandler()); err != nil {
@@ -299,6 +389,130 @@ func runReconcilers(zlog *zap.SugaredLogger, s *tsnet.Server, tsNamespace string
 	}
 }
 
+type reconcilerOpts struct {
+	log                *zap.SugaredLogger
+	tsServer           *tsnet.Server
+	tsClient           *tailscale.Client
+	tailscaleNamespace string       // namespace in which operator resources will be deployed
+	restConfig         *rest.Config // config for connecting to the kube API server
+	proxyImage         string       // <proxy-image-repo>:<proxy-image-tag>
+	// proxyPriorityClassName isPriorityClass to be set for proxy Pods. This
+	// is a legacy mechanism for cluster resource configuration options -
+	// going forward use ProxyClass.
+	// https://kubernetes.io/docs/concepts/scheduling-eviction/pod-priority-preemption/#priorityclass
+	proxyPriorityClassName string
+	// proxyTags are ACL tags to tag proxy auth keys. Multiple tags should
+	// be provided as a string with comma-separated tag values. Proxy tags
+	// default to tag:k8s.
+	// https://tailscale.com/kb/1085/auth-keys
+	proxyTags string
+	// proxyActAsDefaultLoadBalancer determines whether this operator
+	// instance should act as the default ingress controller when looking at
+	// Ingress resources with unset ingress.spec.ingressClassName.
+	// TODO (irbekrm): this setting does not respect the default
+	// IngressClass.
+	// https://kubernetes.io/docs/concepts/services-networking/ingress/#default-ingress-class
+	// We should fix that and preferably integrate with that mechanism as
+	// well - perhaps make the operator itself create the default
+	// IngressClass if this is set to true.
+	proxyActAsDefaultLoadBalancer bool
+	// proxyFirewallMode determines whether non-userspace proxies should use
+	// iptables or nftables for firewall configuration. Accepted values are
+	// iptables, nftables and auto. If set to auto, proxy will automatically
+	// determine which mode is supported for a given host (prefer nftables).
+	// Auto is usually the best choice, unless you want to explicitly set
+	// specific mode for debugging purposes.
+	proxyFirewallMode string
+}
+
+// enqueueAllIngressEgressProxySvcsinNS returns a reconcile request for each
+// ingress/egress proxy headless Service found in the provided namespace.
+func enqueueAllIngressEgressProxySvcsInNS(ns string, cl client.Client, logger *zap.SugaredLogger) handler.MapFunc {
+	return func(ctx context.Context, _ client.Object) []reconcile.Request {
+		reqs := make([]reconcile.Request, 0)
+
+		// Get all headless Services for proxies configured using Service.
+		svcProxyLabels := map[string]string{
+			LabelManaged:    "true",
+			LabelParentType: "svc",
+		}
+		svcHeadlessSvcList := &corev1.ServiceList{}
+		if err := cl.List(ctx, svcHeadlessSvcList, client.InNamespace(ns), client.MatchingLabels(svcProxyLabels)); err != nil {
+			logger.Errorf("error listing headless Services for tailscale ingress/egress Services in operator namespace: %v", err)
+			return nil
+		}
+		for _, svc := range svcHeadlessSvcList.Items {
+			reqs = append(reqs, reconcile.Request{NamespacedName: types.NamespacedName{Namespace: svc.Namespace, Name: svc.Name}})
+		}
+
+		// Get all headless Services for proxies configured using Ingress.
+		ingProxyLabels := map[string]string{
+			LabelManaged:    "true",
+			LabelParentType: "ingress",
+		}
+		ingHeadlessSvcList := &corev1.ServiceList{}
+		if err := cl.List(ctx, ingHeadlessSvcList, client.InNamespace(ns), client.MatchingLabels(ingProxyLabels)); err != nil {
+			logger.Errorf("error listing headless Services for tailscale Ingresses in operator namespace: %v", err)
+			return nil
+		}
+		for _, svc := range ingHeadlessSvcList.Items {
+			reqs = append(reqs, reconcile.Request{NamespacedName: types.NamespacedName{Namespace: svc.Namespace, Name: svc.Name}})
+		}
+		return reqs
+	}
+}
+
+// dnsRecordsReconciler filters EndpointSlice events for which
+// dns-records-reconciler should reconcile a headless Service. The only events
+// it should reconcile are those for EndpointSlices associated with proxy
+// headless Services.
+func dnsRecordsReconcilerEndpointSliceHandler(ctx context.Context, o client.Object) []reconcile.Request {
+	if !isManagedByType(o, "svc") && !isManagedByType(o, "ingress") {
+		return nil
+	}
+	headlessSvcName, ok := o.GetLabels()[discoveryv1.LabelServiceName] // https://kubernetes.io/docs/concepts/services-networking/endpoint-slices/#ownership
+	if !ok {
+		return nil
+	}
+	return []reconcile.Request{{NamespacedName: types.NamespacedName{Namespace: o.GetNamespace(), Name: headlessSvcName}}}
+}
+
+// dnsRecordsReconcilerServiceHandler filters Service events for which
+// dns-records-reconciler should reconcile. If the event is for a cluster
+// ingress/cluster egress proxy's headless Service, returns the Service for
+// reconcile.
+func dnsRecordsReconcilerServiceHandler(ctx context.Context, o client.Object) []reconcile.Request {
+	if isManagedByType(o, "svc") || isManagedByType(o, "ingress") {
+		return []reconcile.Request{{NamespacedName: types.NamespacedName{Namespace: o.GetNamespace(), Name: o.GetName()}}}
+	}
+	return nil
+}
+
+// dnsRecordsReconcilerIngressHandler filters Ingress events to ensure that
+// dns-records-reconciler only reconciles on tailscale Ingress events. When an
+// event is observed on a tailscale Ingress, reconcile the proxy headless Service.
+func dnsRecordsReconcilerIngressHandler(ns string, isDefaultLoadBalancer bool, cl client.Client, logger *zap.SugaredLogger) handler.MapFunc {
+	return func(ctx context.Context, o client.Object) []reconcile.Request {
+		ing, ok := o.(*networkingv1.Ingress)
+		if !ok {
+			return nil
+		}
+		if !isDefaultLoadBalancer && (ing.Spec.IngressClassName == nil || *ing.Spec.IngressClassName != "tailscale") {
+			return nil
+		}
+		proxyResourceLabels := childResourceLabels(ing.Name, ing.Namespace, "ingress")
+		headlessSvc, err := getSingleObject[corev1.Service](ctx, cl, ns, proxyResourceLabels)
+		if err != nil {
+			logger.Errorf("error getting headless Service from parent labels: %v", err)
+			return nil
+		}
+		if headlessSvc == nil {
+			return nil
+		}
+		return []reconcile.Request{{NamespacedName: types.NamespacedName{Namespace: headlessSvc.Namespace, Name: headlessSvc.Name}}}
+	}
+}
+
 type tsClient interface {
 	CreateKey(ctx context.Context, caps tailscale.KeyCapabilities) (string, *tailscale.Key, error)
 	DeleteDevice(ctx context.Context, nodeStableID string) error
@@ -321,6 +535,7 @@ func parentFromObjectLabels(o client.Object) types.NamespacedName {
 		Name:      ls[LabelParentName],
 	}
 }
+
 func managedResourceHandlerForType(typ string) handler.MapFunc {
 	return func(_ context.Context, o client.Object) []reconcile.Request {
 		if !isManagedByType(o, typ) {
@@ -330,14 +545,115 @@ func managedResourceHandlerForType(typ string) handler.MapFunc {
 			{NamespacedName: parentFromObjectLabels(o)},
 		}
 	}
+}
 
+// proxyClassHandlerForSvc returns a handler that, for a given ProxyClass,
+// returns a list of reconcile requests for all Services labeled with
+// tailscale.com/proxy-class: <proxy class name>.
+func proxyClassHandlerForSvc(cl client.Client, logger *zap.SugaredLogger) handler.MapFunc {
+	return func(ctx context.Context, o client.Object) []reconcile.Request {
+		svcList := new(corev1.ServiceList)
+		labels := map[string]string{
+			LabelProxyClass: o.GetName(),
+		}
+		if err := cl.List(ctx, svcList, client.MatchingLabels(labels)); err != nil {
+			logger.Debugf("error listing Services for ProxyClass: %v", err)
+			return nil
+		}
+		reqs := make([]reconcile.Request, 0)
+		for _, svc := range svcList.Items {
+			reqs = append(reqs, reconcile.Request{NamespacedName: client.ObjectKeyFromObject(&svc)})
+		}
+		return reqs
+	}
+}
+
+// proxyClassHandlerForIngress returns a handler that, for a given ProxyClass,
+// returns a list of reconcile requests for all Ingresses labeled with
+// tailscale.com/proxy-class: <proxy class name>.
+func proxyClassHandlerForIngress(cl client.Client, logger *zap.SugaredLogger) handler.MapFunc {
+	return func(ctx context.Context, o client.Object) []reconcile.Request {
+		ingList := new(networkingv1.IngressList)
+		labels := map[string]string{
+			LabelProxyClass: o.GetName(),
+		}
+		if err := cl.List(ctx, ingList, client.MatchingLabels(labels)); err != nil {
+			logger.Debugf("error listing Ingresses for ProxyClass: %v", err)
+			return nil
+		}
+		reqs := make([]reconcile.Request, 0)
+		for _, ing := range ingList.Items {
+			reqs = append(reqs, reconcile.Request{NamespacedName: client.ObjectKeyFromObject(&ing)})
+		}
+		return reqs
+	}
+}
+
+// proxyClassHandlerForConnector returns a handler that, for a given ProxyClass,
+// returns a list of reconcile requests for all Connectors that have
+// .spec.proxyClass set.
+func proxyClassHandlerForConnector(cl client.Client, logger *zap.SugaredLogger) handler.MapFunc {
+	return func(ctx context.Context, o client.Object) []reconcile.Request {
+		connList := new(tsapi.ConnectorList)
+		if err := cl.List(ctx, connList); err != nil {
+			logger.Debugf("error listing Connectors for ProxyClass: %v", err)
+			return nil
+		}
+		reqs := make([]reconcile.Request, 0)
+		proxyClassName := o.GetName()
+		for _, conn := range connList.Items {
+			if conn.Spec.ProxyClass == proxyClassName {
+				reqs = append(reqs, reconcile.Request{NamespacedName: client.ObjectKeyFromObject(&conn)})
+			}
+		}
+		return reqs
+	}
+}
+
+// serviceHandlerForIngress returns a handler for Service events for ingress
+// reconciler that ensures that if the Service associated with an event is of
+// interest to the reconciler, the associated Ingress(es) gets be reconciled.
+// The Services of interest are backend Services for tailscale Ingress and
+// managed Services for an StatefulSet for a proxy configured for tailscale
+// Ingress
+func serviceHandlerForIngress(cl client.Client, logger *zap.SugaredLogger) handler.MapFunc {
+	return func(ctx context.Context, o client.Object) []reconcile.Request {
+		if isManagedByType(o, "ingress") {
+			ingName := parentFromObjectLabels(o)
+			return []reconcile.Request{{NamespacedName: ingName}}
+		}
+		ingList := networkingv1.IngressList{}
+		if err := cl.List(ctx, &ingList, client.InNamespace(o.GetNamespace())); err != nil {
+			logger.Debugf("error listing Ingresses: %v", err)
+			return nil
+		}
+		reqs := make([]reconcile.Request, 0)
+		for _, ing := range ingList.Items {
+			if ing.Spec.IngressClassName == nil || *ing.Spec.IngressClassName != tailscaleIngressClassName {
+				return nil
+			}
+			if ing.Spec.DefaultBackend != nil && ing.Spec.DefaultBackend.Service != nil && ing.Spec.DefaultBackend.Service.Name == o.GetName() {
+				reqs = append(reqs, reconcile.Request{NamespacedName: client.ObjectKeyFromObject(&ing)})
+			}
+			for _, rule := range ing.Spec.Rules {
+				if rule.HTTP == nil {
+					continue
+				}
+				for _, path := range rule.HTTP.Paths {
+					if path.Backend.Service != nil && path.Backend.Service.Name == o.GetName() {
+						reqs = append(reqs, reconcile.Request{NamespacedName: client.ObjectKeyFromObject(&ing)})
+					}
+				}
+			}
+		}
+		return reqs
+	}
 }
 
 func serviceHandler(_ context.Context, o client.Object) []reconcile.Request {
 	if isManagedByType(o, "svc") {
 		// If this is a Service managed by a Service we want to enqueue its parent
 		return []reconcile.Request{{NamespacedName: parentFromObjectLabels(o)}}
-
 	}
 	if isManagedResource(o) {
 		// If this is a Servce managed by a resource that is not a Service, we leave it alone
@@ -352,7 +668,6 @@ func serviceHandler(_ context.Context, o client.Object) []reconcile.Request {
 			},
 		},
 	}
-
 }
 
 // isMagicDNSName reports whether name is a full tailnet node FQDN (with or

cmd/k8s-operator/operator_test.go

@@ -6,16 +6,24 @@
 package main
 
 import (
+	"context"
 	"fmt"
 	"testing"
 
+	"github.com/google/go-cmp/cmp"
 	"go.uber.org/zap"
 	appsv1 "k8s.io/api/apps/v1"
 	corev1 "k8s.io/api/core/v1"
+	networkingv1 "k8s.io/api/networking/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
 	"sigs.k8s.io/controller-runtime/pkg/client/fake"
+	"sigs.k8s.io/controller-runtime/pkg/reconcile"
+	tsapi "tailscale.com/k8s-operator/apis/v1alpha1"
+	"tailscale.com/net/dns/resolvconffile"
 	"tailscale.com/types/ptr"
+	"tailscale.com/util/dnsname"
+	"tailscale.com/util/mak"
 )
 
 func TestLoadBalancerClass(t *testing.T) {
@@ -67,9 +75,9 @@ func TestLoadBalancerClass(t *testing.T) {
 		clusterTargetIP: "10.20.30.40",
 	}
 
-	expectEqual(t, fc, expectedSecret(t, opts))
-	expectEqual(t, fc, expectedHeadlessService(shortName))
-	expectEqual(t, fc, expectedSTS(opts))
+	expectEqual(t, fc, expectedSecret(t, opts), nil)
+	expectEqual(t, fc, expectedHeadlessService(shortName, "svc"), nil)
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
 
 	// Normally the Tailscale proxy pod would come up here and write its info
 	// into the secret. Simulate that, then verify reconcile again and verify
@@ -112,7 +120,7 @@ func TestLoadBalancerClass(t *testing.T) {
 			},
 		},
 	}
-	expectEqual(t, fc, want)
+	expectEqual(t, fc, want, nil)
 
 	// Turn the service back into a ClusterIP service, which should make the
 	// operator clean up.
@@ -151,7 +159,7 @@ func TestLoadBalancerClass(t *testing.T) {
 			Type:      corev1.ServiceTypeClusterIP,
 		},
 	}
-	expectEqual(t, fc, want)
+	expectEqual(t, fc, want, nil)
 }
 
 func TestTailnetTargetFQDNAnnotation(t *testing.T) {
@@ -208,9 +216,9 @@ func TestTailnetTargetFQDNAnnotation(t *testing.T) {
 		hostname:          "default-test",
 	}
 
-	expectEqual(t, fc, expectedSecret(t, o))
-	expectEqual(t, fc, expectedHeadlessService(shortName))
-	expectEqual(t, fc, expectedSTS(o))
+	expectEqual(t, fc, expectedSecret(t, o), nil)
+	expectEqual(t, fc, expectedHeadlessService(shortName, "svc"), nil)
+	expectEqual(t, fc, expectedSTS(t, fc, o), removeHashAnnotation)
 	want := &corev1.Service{
 		TypeMeta: metav1.TypeMeta{
 			Kind:       "Service",
@@ -231,10 +239,10 @@ func TestTailnetTargetFQDNAnnotation(t *testing.T) {
 			Selector:     nil,
 		},
 	}
-	expectEqual(t, fc, want)
-	expectEqual(t, fc, expectedSecret(t, o))
-	expectEqual(t, fc, expectedHeadlessService(shortName))
-	expectEqual(t, fc, expectedSTS(o))
+	expectEqual(t, fc, want, nil)
+	expectEqual(t, fc, expectedSecret(t, o), nil)
+	expectEqual(t, fc, expectedHeadlessService(shortName, "svc"), nil)
+	expectEqual(t, fc, expectedSTS(t, fc, o), removeHashAnnotation)
 
 	// Change the tailscale-target-fqdn annotation which should update the
 	// StatefulSet
@@ -318,9 +326,9 @@ func TestTailnetTargetIPAnnotation(t *testing.T) {
 		hostname:        "default-test",
 	}
 
-	expectEqual(t, fc, expectedSecret(t, o))
-	expectEqual(t, fc, expectedHeadlessService(shortName))
-	expectEqual(t, fc, expectedSTS(o))
+	expectEqual(t, fc, expectedSecret(t, o), nil)
+	expectEqual(t, fc, expectedHeadlessService(shortName, "svc"), nil)
+	expectEqual(t, fc, expectedSTS(t, fc, o), removeHashAnnotation)
 	want := &corev1.Service{
 		TypeMeta: metav1.TypeMeta{
 			Kind:       "Service",
@@ -341,10 +349,10 @@ func TestTailnetTargetIPAnnotation(t *testing.T) {
 			Selector:     nil,
 		},
 	}
-	expectEqual(t, fc, want)
-	expectEqual(t, fc, expectedSecret(t, o))
-	expectEqual(t, fc, expectedHeadlessService(shortName))
-	expectEqual(t, fc, expectedSTS(o))
+	expectEqual(t, fc, want, nil)
+	expectEqual(t, fc, expectedSecret(t, o), nil)
+	expectEqual(t, fc, expectedHeadlessService(shortName, "svc"), nil)
+	expectEqual(t, fc, expectedSTS(t, fc, o), removeHashAnnotation)
 
 	// Change the tailscale-target-ip annotation which should update the
 	// StatefulSet
@@ -425,9 +433,9 @@ func TestAnnotations(t *testing.T) {
 		clusterTargetIP: "10.20.30.40",
 	}
 
-	expectEqual(t, fc, expectedSecret(t, o))
-	expectEqual(t, fc, expectedHeadlessService(shortName))
-	expectEqual(t, fc, expectedSTS(o))
+	expectEqual(t, fc, expectedSecret(t, o), nil)
+	expectEqual(t, fc, expectedHeadlessService(shortName, "svc"), nil)
+	expectEqual(t, fc, expectedSTS(t, fc, o), removeHashAnnotation)
 	want := &corev1.Service{
 		TypeMeta: metav1.TypeMeta{
 			Kind:       "Service",
@@ -447,7 +455,7 @@ func TestAnnotations(t *testing.T) {
 			Type:      corev1.ServiceTypeClusterIP,
 		},
 	}
-	expectEqual(t, fc, want)
+	expectEqual(t, fc, want, nil)
 
 	// Turn the service back into a ClusterIP service, which should make the
 	// operator clean up.
@@ -479,7 +487,7 @@ func TestAnnotations(t *testing.T) {
 			Type:      corev1.ServiceTypeClusterIP,
 		},
 	}
-	expectEqual(t, fc, want)
+	expectEqual(t, fc, want, nil)
 }
 
 func TestAnnotationIntoLB(t *testing.T) {
@@ -533,9 +541,9 @@ func TestAnnotationIntoLB(t *testing.T) {
 		clusterTargetIP: "10.20.30.40",
 	}
 
-	expectEqual(t, fc, expectedSecret(t, o))
-	expectEqual(t, fc, expectedHeadlessService(shortName))
-	expectEqual(t, fc, expectedSTS(o))
+	expectEqual(t, fc, expectedSecret(t, o), nil)
+	expectEqual(t, fc, expectedHeadlessService(shortName, "svc"), nil)
+	expectEqual(t, fc, expectedSTS(t, fc, o), removeHashAnnotation)
 
 	// Normally the Tailscale proxy pod would come up here and write its info
 	// into the secret. Simulate that, since it would have normally happened at
@@ -568,7 +576,7 @@ func TestAnnotationIntoLB(t *testing.T) {
 			Type:      corev1.ServiceTypeClusterIP,
 		},
 	}
-	expectEqual(t, fc, want)
+	expectEqual(t, fc, want, nil)
 
 	// Remove Tailscale's annotation, and at the same time convert the service
 	// into a tailscale LoadBalancer.
@@ -579,8 +587,8 @@ func TestAnnotationIntoLB(t *testing.T) {
 	})
 	expectReconciled(t, sr, "default", "test")
 	// None of the proxy machinery should have changed...
-	expectEqual(t, fc, expectedHeadlessService(shortName))
-	expectEqual(t, fc, expectedSTS(o))
+	expectEqual(t, fc, expectedHeadlessService(shortName, "svc"), nil)
+	expectEqual(t, fc, expectedSTS(t, fc, o), removeHashAnnotation)
 	// ... but the service should have a LoadBalancer status.
 
 	want = &corev1.Service{
@@ -612,7 +620,7 @@ func TestAnnotationIntoLB(t *testing.T) {
 			},
 		},
 	}
-	expectEqual(t, fc, want)
+	expectEqual(t, fc, want, nil)
 }
 
 func TestLBIntoAnnotation(t *testing.T) {
@@ -664,9 +672,9 @@ func TestLBIntoAnnotation(t *testing.T) {
 		clusterTargetIP: "10.20.30.40",
 	}
 
-	expectEqual(t, fc, expectedSecret(t, o))
-	expectEqual(t, fc, expectedHeadlessService(shortName))
-	expectEqual(t, fc, expectedSTS(o))
+	expectEqual(t, fc, expectedSecret(t, o), nil)
+	expectEqual(t, fc, expectedHeadlessService(shortName, "svc"), nil)
+	expectEqual(t, fc, expectedSTS(t, fc, o), removeHashAnnotation)
 
 	// Normally the Tailscale proxy pod would come up here and write its info
 	// into the secret. Simulate that, then verify reconcile again and verify
@@ -709,7 +717,7 @@ func TestLBIntoAnnotation(t *testing.T) {
 			},
 		},
 	}
-	expectEqual(t, fc, want)
+	expectEqual(t, fc, want, nil)
 
 	// Turn the service back into a ClusterIP service, but also add the
 	// tailscale annotation.
@@ -728,8 +736,8 @@ func TestLBIntoAnnotation(t *testing.T) {
 	})
 	expectReconciled(t, sr, "default", "test")
 
-	expectEqual(t, fc, expectedHeadlessService(shortName))
-	expectEqual(t, fc, expectedSTS(o))
+	expectEqual(t, fc, expectedHeadlessService(shortName, "svc"), nil)
+	expectEqual(t, fc, expectedSTS(t, fc, o), removeHashAnnotation)
 
 	want = &corev1.Service{
 		TypeMeta: metav1.TypeMeta{
@@ -750,7 +758,7 @@ func TestLBIntoAnnotation(t *testing.T) {
 			Type:      corev1.ServiceTypeClusterIP,
 		},
 	}
-	expectEqual(t, fc, want)
+	expectEqual(t, fc, want, nil)
 }
 
 func TestCustomHostname(t *testing.T) {
@@ -805,9 +813,9 @@ func TestCustomHostname(t *testing.T) {
 		clusterTargetIP: "10.20.30.40",
 	}
 
-	expectEqual(t, fc, expectedSecret(t, o))
-	expectEqual(t, fc, expectedHeadlessService(shortName))
-	expectEqual(t, fc, expectedSTS(o))
+	expectEqual(t, fc, expectedSecret(t, o), nil)
+	expectEqual(t, fc, expectedHeadlessService(shortName, "svc"), nil)
+	expectEqual(t, fc, expectedSTS(t, fc, o), removeHashAnnotation)
 	want := &corev1.Service{
 		TypeMeta: metav1.TypeMeta{
 			Kind:       "Service",
@@ -828,7 +836,7 @@ func TestCustomHostname(t *testing.T) {
 			Type:      corev1.ServiceTypeClusterIP,
 		},
 	}
-	expectEqual(t, fc, want)
+	expectEqual(t, fc, want, nil)
 
 	// Turn the service back into a ClusterIP service, which should make the
 	// operator clean up.
@@ -863,7 +871,7 @@ func TestCustomHostname(t *testing.T) {
 			Type:      corev1.ServiceTypeClusterIP,
 		},
 	}
-	expectEqual(t, fc, want)
+	expectEqual(t, fc, want, nil)
 }
 
 func TestCustomPriorityClassName(t *testing.T) {
@@ -920,7 +928,104 @@ func TestCustomPriorityClassName(t *testing.T) {
 		clusterTargetIP:   "10.20.30.40",
 	}
 
-	expectEqual(t, fc, expectedSTS(o))
+	expectEqual(t, fc, expectedSTS(t, fc, o), removeHashAnnotation)
+}
+
+func TestProxyClassForService(t *testing.T) {
+	// Setup
+	pc := &tsapi.ProxyClass{
+		ObjectMeta: metav1.ObjectMeta{Name: "custom-metadata"},
+		Spec: tsapi.ProxyClassSpec{StatefulSet: &tsapi.StatefulSet{
+			Labels:      map[string]string{"foo": "bar"},
+			Annotations: map[string]string{"bar.io/foo": "some-val"},
+			Pod:         &tsapi.Pod{Annotations: map[string]string{"foo.io/bar": "some-val"}}}},
+	}
+	fc := fake.NewClientBuilder().
+		WithScheme(tsapi.GlobalScheme).
+		WithObjects(pc).
+		WithStatusSubresource(pc).
+		Build()
+	ft := &fakeTSClient{}
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+	sr := &ServiceReconciler{
+		Client: fc,
+		ssr: &tailscaleSTSReconciler{
+			Client:            fc,
+			tsClient:          ft,
+			defaultTags:       []string{"tag:k8s"},
+			operatorNamespace: "operator-ns",
+			proxyImage:        "tailscale/tailscale",
+		},
+		logger: zl.Sugar(),
+	}
+
+	// 1. A new tailscale LoadBalancer Service is created without any
+	// ProxyClass. Resources get created for it as usual.
+	mustCreate(t, fc, &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: "default",
+			// The apiserver is supposed to set the UID, but the fake client
+			// doesn't. So, set it explicitly because other code later depends
+			// on it being set.
+			UID: types.UID("1234-UID"),
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP:         "10.20.30.40",
+			Type:              corev1.ServiceTypeLoadBalancer,
+			LoadBalancerClass: ptr.To("tailscale"),
+		},
+	})
+	expectReconciled(t, sr, "default", "test")
+	fullName, shortName := findGenName(t, fc, "default", "test", "svc")
+	opts := configOpts{
+		stsName:         shortName,
+		secretName:      fullName,
+		namespace:       "default",
+		parentType:      "svc",
+		hostname:        "default-test",
+		clusterTargetIP: "10.20.30.40",
+	}
+	expectEqual(t, fc, expectedSecret(t, opts), nil)
+	expectEqual(t, fc, expectedHeadlessService(shortName, "svc"), nil)
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
+
+	// 2. The Service gets updated with tailscale.com/proxy-class label
+	// pointing at the 'custom-metadata' ProxyClass. The ProxyClass is not
+	// yet ready, so no changes are actually applied to the proxy resources.
+	mustUpdate(t, fc, "default", "test", func(svc *corev1.Service) {
+		mak.Set(&svc.Labels, LabelProxyClass, "custom-metadata")
+	})
+	expectReconciled(t, sr, "default", "test")
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
+
+	// 3. ProxyClass is set to Ready, the Service gets reconciled by the
+	// services-reconciler and the customization from the ProxyClass is
+	// applied to the proxy resources.
+	mustUpdateStatus(t, fc, "", "custom-metadata", func(pc *tsapi.ProxyClass) {
+		pc.Status = tsapi.ProxyClassStatus{
+			Conditions: []tsapi.ConnectorCondition{{
+				Status:             metav1.ConditionTrue,
+				Type:               tsapi.ProxyClassready,
+				ObservedGeneration: pc.Generation,
+			}}}
+	})
+	opts.proxyClass = pc.Name
+	expectReconciled(t, sr, "default", "test")
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
+
+	// 4. tailscale.com/proxy-class label is removed from the Service, the
+	// configuration from the ProxyClass is removed from the cluster
+	// resources.
+	mustUpdate(t, fc, "default", "test", func(svc *corev1.Service) {
+		delete(svc.Labels, LabelProxyClass)
+	})
+	opts.proxyClass = ""
+	expectReconciled(t, sr, "default", "test")
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
 }
 
 func TestDefaultLoadBalancer(t *testing.T) {
@@ -964,7 +1069,7 @@ func TestDefaultLoadBalancer(t *testing.T) {
 
 	fullName, shortName := findGenName(t, fc, "default", "test", "svc")
 
-	expectEqual(t, fc, expectedHeadlessService(shortName))
+	expectEqual(t, fc, expectedHeadlessService(shortName, "svc"), nil)
 	o := configOpts{
 		stsName:         shortName,
 		secretName:      fullName,
@@ -973,7 +1078,8 @@ func TestDefaultLoadBalancer(t *testing.T) {
 		hostname:        "default-test",
 		clusterTargetIP: "10.20.30.40",
 	}
-	expectEqual(t, fc, expectedSTS(o))
+	expectEqual(t, fc, expectedSTS(t, fc, o), removeHashAnnotation)
+
 }
 
 func TestProxyFirewallMode(t *testing.T) {
@@ -1026,10 +1132,70 @@ func TestProxyFirewallMode(t *testing.T) {
 		firewallMode:    "nftables",
 		clusterTargetIP: "10.20.30.40",
 	}
-	expectEqual(t, fc, expectedSTS(o))
-
+	expectEqual(t, fc, expectedSTS(t, fc, o), removeHashAnnotation)
 }
 
+func TestTailscaledConfigfileHash(t *testing.T) {
+	fc := fake.NewFakeClient()
+	ft := &fakeTSClient{}
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+	sr := &ServiceReconciler{
+		Client: fc,
+		ssr: &tailscaleSTSReconciler{
+			Client:            fc,
+			tsClient:          ft,
+			defaultTags:       []string{"tag:k8s"},
+			operatorNamespace: "operator-ns",
+			proxyImage:        "tailscale/tailscale",
+		},
+		logger:                zl.Sugar(),
+		isDefaultLoadBalancer: true,
+	}
+
+	// Create a service that we should manage, and check that the initial round
+	// of objects looks right.
+	mustCreate(t, fc, &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: "default",
+			// The apiserver is supposed to set the UID, but the fake client
+			// doesn't. So, set it explicitly because other code later depends
+			// on it being set.
+			UID: types.UID("1234-UID"),
+		},
+		Spec: corev1.ServiceSpec{
+			ClusterIP: "10.20.30.40",
+			Type:      corev1.ServiceTypeLoadBalancer,
+		},
+	})
+
+	expectReconciled(t, sr, "default", "test")
+
+	fullName, shortName := findGenName(t, fc, "default", "test", "svc")
+	o := configOpts{
+		stsName:         shortName,
+		secretName:      fullName,
+		namespace:       "default",
+		parentType:      "svc",
+		hostname:        "default-test",
+		clusterTargetIP: "10.20.30.40",
+		confFileHash:    "e09bededa0379920141cbd0b0dbdf9b8b66545877f9e8397423f5ce3e1ba439e",
+	}
+	expectEqual(t, fc, expectedSTS(t, fc, o), nil)
+
+	// 2. Hostname gets changed, configfile is updated and a new hash value
+	// is produced.
+	mustUpdate(t, fc, "default", "test", func(svc *corev1.Service) {
+		mak.Set(&svc.Annotations, AnnotationHostname, "another-test")
+	})
+	o.hostname = "another-test"
+	o.confFileHash = "5d754cf55463135ee34aa9821f2fd8483b53eb0570c3740c84a086304f427684"
+	expectReconciled(t, sr, "default", "test")
+	expectEqual(t, fc, expectedSTS(t, fc, o), nil)
+}
 func Test_isMagicDNSName(t *testing.T) {
 	tests := []struct {
 		in   string
@@ -1056,3 +1222,279 @@ func Test_isMagicDNSName(t *testing.T) {
 		})
 	}
 }
+
+func Test_serviceHandlerForIngress(t *testing.T) {
+	fc := fake.NewFakeClient()
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// 1. An event on a headless Service for a tailscale Ingress results in
+	// the Ingress being reconciled.
+	mustCreate(t, fc, &networkingv1.Ingress{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "ing-1",
+			Namespace: "ns-1",
+		},
+		Spec: networkingv1.IngressSpec{IngressClassName: ptr.To(tailscaleIngressClassName)},
+	})
+	svc1 := &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "headless-1",
+			Namespace: "tailscale",
+			Labels: map[string]string{
+				LabelManaged:         "true",
+				LabelParentName:      "ing-1",
+				LabelParentNamespace: "ns-1",
+				LabelParentType:      "ingress",
+			},
+		},
+	}
+	mustCreate(t, fc, svc1)
+	wantReqs := []reconcile.Request{{NamespacedName: types.NamespacedName{Namespace: "ns-1", Name: "ing-1"}}}
+	gotReqs := serviceHandlerForIngress(fc, zl.Sugar())(context.Background(), svc1)
+	if diff := cmp.Diff(gotReqs, wantReqs); diff != "" {
+		t.Fatalf("unexpected reconcile requests (-got +want):\n%s", diff)
+	}
+
+	// 2. An event on a Service that is the default backend for a tailscale
+	// Ingress results in the Ingress being reconciled.
+	mustCreate(t, fc, &networkingv1.Ingress{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "ing-2",
+			Namespace: "ns-2",
+		},
+		Spec: networkingv1.IngressSpec{
+			DefaultBackend: &networkingv1.IngressBackend{
+				Service: &networkingv1.IngressServiceBackend{Name: "def-backend"},
+			},
+			IngressClassName: ptr.To(tailscaleIngressClassName),
+		},
+	})
+	backendSvc := &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "def-backend",
+			Namespace: "ns-2",
+		},
+	}
+	mustCreate(t, fc, backendSvc)
+	wantReqs = []reconcile.Request{{NamespacedName: types.NamespacedName{Namespace: "ns-2", Name: "ing-2"}}}
+	gotReqs = serviceHandlerForIngress(fc, zl.Sugar())(context.Background(), backendSvc)
+	if diff := cmp.Diff(gotReqs, wantReqs); diff != "" {
+		t.Fatalf("unexpected reconcile requests (-got +want):\n%s", diff)
+	}
+
+	// 3. An event on a Service that is one of the non-default backends for
+	// a tailscale Ingress results in the Ingress being reconciled.
+	mustCreate(t, fc, &networkingv1.Ingress{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "ing-3",
+			Namespace: "ns-3",
+		},
+		Spec: networkingv1.IngressSpec{
+			IngressClassName: ptr.To(tailscaleIngressClassName),
+			Rules: []networkingv1.IngressRule{{IngressRuleValue: networkingv1.IngressRuleValue{HTTP: &networkingv1.HTTPIngressRuleValue{
+				Paths: []networkingv1.HTTPIngressPath{
+					{Backend: networkingv1.IngressBackend{Service: &networkingv1.IngressServiceBackend{Name: "backend"}}}},
+			}}}},
+		},
+	})
+	backendSvc2 := &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "backend",
+			Namespace: "ns-3",
+		},
+	}
+	mustCreate(t, fc, backendSvc2)
+	wantReqs = []reconcile.Request{{NamespacedName: types.NamespacedName{Namespace: "ns-3", Name: "ing-3"}}}
+	gotReqs = serviceHandlerForIngress(fc, zl.Sugar())(context.Background(), backendSvc2)
+	if diff := cmp.Diff(gotReqs, wantReqs); diff != "" {
+		t.Fatalf("unexpected reconcile requests (-got +want):\n%s", diff)
+	}
+
+	// 4. An event on a Service that is a backend for an Ingress that is not
+	// tailscale Ingress does not result in an Ingress reconcile.
+	mustCreate(t, fc, &networkingv1.Ingress{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "ing-4",
+			Namespace: "ns-4",
+		},
+		Spec: networkingv1.IngressSpec{
+			Rules: []networkingv1.IngressRule{{IngressRuleValue: networkingv1.IngressRuleValue{HTTP: &networkingv1.HTTPIngressRuleValue{
+				Paths: []networkingv1.HTTPIngressPath{
+					{Backend: networkingv1.IngressBackend{Service: &networkingv1.IngressServiceBackend{Name: "non-ts-backend"}}}},
+			}}}},
+		},
+	})
+	nonTSBackend := &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "non-ts-backend",
+			Namespace: "ns-4",
+		},
+	}
+	mustCreate(t, fc, nonTSBackend)
+	gotReqs = serviceHandlerForIngress(fc, zl.Sugar())(context.Background(), nonTSBackend)
+	if len(gotReqs) > 0 {
+		t.Errorf("unexpected reconcile request for a Service that does not belong to a Tailscale Ingress: %#+v\n", gotReqs)
+	}
+
+	// 5. An event on a Service not related to any Ingress does not result
+	// in an Ingress reconcile.
+	someSvc := &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "some-svc",
+			Namespace: "ns-4",
+		},
+	}
+	mustCreate(t, fc, someSvc)
+	gotReqs = serviceHandlerForIngress(fc, zl.Sugar())(context.Background(), someSvc)
+	if len(gotReqs) > 0 {
+		t.Errorf("unexpected reconcile request for a Service that does not belong to any Ingress: %#+v\n", gotReqs)
+	}
+}
+
+func Test_clusterDomainFromResolverConf(t *testing.T) {
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+	tests := []struct {
+		name      string
+		conf      *resolvconffile.Config
+		namespace string
+		want      string
+	}{
+		{
+			name: "success- custom domain",
+			conf: &resolvconffile.Config{
+				SearchDomains: []dnsname.FQDN{toFQDN(t, "foo.svc.department.org.io"), toFQDN(t, "svc.department.org.io"), toFQDN(t, "department.org.io")},
+			},
+			namespace: "foo",
+			want:      "department.org.io",
+		},
+		{
+			name: "success- default domain",
+			conf: &resolvconffile.Config{
+				SearchDomains: []dnsname.FQDN{toFQDN(t, "foo.svc.cluster.local."), toFQDN(t, "svc.cluster.local."), toFQDN(t, "cluster.local.")},
+			},
+			namespace: "foo",
+			want:      "cluster.local",
+		},
+		{
+			name: "only two search domains found",
+			conf: &resolvconffile.Config{
+				SearchDomains: []dnsname.FQDN{toFQDN(t, "svc.department.org.io"), toFQDN(t, "department.org.io")},
+			},
+			namespace: "foo",
+			want:      "cluster.local",
+		},
+		{
+			name: "first search domain does not match the expected structure",
+			conf: &resolvconffile.Config{
+				SearchDomains: []dnsname.FQDN{toFQDN(t, "foo.bar.department.org.io"), toFQDN(t, "svc.department.org.io"), toFQDN(t, "some.other.fqdn")},
+			},
+			namespace: "foo",
+			want:      "cluster.local",
+		},
+		{
+			name: "second search domain does not match the expected structure",
+			conf: &resolvconffile.Config{
+				SearchDomains: []dnsname.FQDN{toFQDN(t, "foo.svc.department.org.io"), toFQDN(t, "foo.department.org.io"), toFQDN(t, "some.other.fqdn")},
+			},
+			namespace: "foo",
+			want:      "cluster.local",
+		},
+		{
+			name: "third search domain does not match the expected structure",
+			conf: &resolvconffile.Config{
+				SearchDomains: []dnsname.FQDN{toFQDN(t, "foo.svc.department.org.io"), toFQDN(t, "svc.department.org.io"), toFQDN(t, "some.other.fqdn")},
+			},
+			namespace: "foo",
+			want:      "cluster.local",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := clusterDomainFromResolverConf(tt.conf, tt.namespace, zl.Sugar()); got != tt.want {
+				t.Errorf("clusterDomainFromResolverConf() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func Test_externalNameService(t *testing.T) {
+	fc := fake.NewFakeClient()
+	ft := &fakeTSClient{}
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// 1. A External name Service that should be exposed via Tailscale gets
+	// created.
+	sr := &ServiceReconciler{
+		Client: fc,
+		ssr: &tailscaleSTSReconciler{
+			Client:            fc,
+			tsClient:          ft,
+			defaultTags:       []string{"tag:k8s"},
+			operatorNamespace: "operator-ns",
+			proxyImage:        "tailscale/tailscale",
+		},
+		logger: zl.Sugar(),
+	}
+
+	// 1. Create an ExternalName Service that we should manage, and check that the initial round
+	// of objects looks right.
+	mustCreate(t, fc, &corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: "default",
+			// The apiserver is supposed to set the UID, but the fake client
+			// doesn't. So, set it explicitly because other code later depends
+			// on it being set.
+			UID: types.UID("1234-UID"),
+			Annotations: map[string]string{
+				AnnotationExpose: "true",
+			},
+		},
+		Spec: corev1.ServiceSpec{
+			Type:         corev1.ServiceTypeExternalName,
+			ExternalName: "foo.com",
+		},
+	})
+
+	expectReconciled(t, sr, "default", "test")
+
+	fullName, shortName := findGenName(t, fc, "default", "test", "svc")
+	opts := configOpts{
+		stsName:          shortName,
+		secretName:       fullName,
+		namespace:        "default",
+		parentType:       "svc",
+		hostname:         "default-test",
+		clusterTargetDNS: "foo.com",
+	}
+
+	expectEqual(t, fc, expectedSecret(t, opts), nil)
+	expectEqual(t, fc, expectedHeadlessService(shortName, "svc"), nil)
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
+
+	// 2. Change the ExternalName and verify that changes get propagated.
+	mustUpdate(t, sr, "default", "test", func(s *corev1.Service) {
+		s.Spec.ExternalName = "bar.com"
+	})
+	expectReconciled(t, sr, "default", "test")
+	opts.clusterTargetDNS = "bar.com"
+	expectEqual(t, fc, expectedSTS(t, fc, opts), removeHashAnnotation)
+}
+
+func toFQDN(t *testing.T, s string) dnsname.FQDN {
+	t.Helper()
+	fqdn, err := dnsname.ToFQDN(s)
+	if err != nil {
+		t.Fatalf("error coverting %q to dnsname.FQDN: %v", s, err)
+	}
+	return fqdn
+}

cmd/k8s-operator/proxyclass.go

@@ -0,0 +1,122 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !plan9
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"go.uber.org/zap"
+	corev1 "k8s.io/api/core/v1"
+	apiequality "k8s.io/apimachinery/pkg/api/equality"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	apivalidation "k8s.io/apimachinery/pkg/api/validation"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	metavalidation "k8s.io/apimachinery/pkg/apis/meta/v1/validation"
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	"k8s.io/client-go/tools/record"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/reconcile"
+	tsoperator "tailscale.com/k8s-operator"
+	tsapi "tailscale.com/k8s-operator/apis/v1alpha1"
+	"tailscale.com/tstime"
+)
+
+const (
+	reasonProxyClassInvalid  = "ProxyClassInvalid"
+	reasonProxyClassValid    = "ProxyClassValid"
+	reasonCustomTSEnvVar     = "CustomTSEnvVar"
+	messageProxyClassInvalid = "ProxyClass is not valid: %v"
+	messageCustomTSEnvVar    = "ProxyClass overrides the default value for %s env var for %s container. Running with custom values for Tailscale env vars is not recommended and might break in the future."
+)
+
+type ProxyClassReconciler struct {
+	client.Client
+
+	recorder record.EventRecorder
+	logger   *zap.SugaredLogger
+	clock    tstime.Clock
+}
+
+func (pcr *ProxyClassReconciler) Reconcile(ctx context.Context, req reconcile.Request) (res reconcile.Result, err error) {
+	logger := pcr.logger.With("ProxyClass", req.Name)
+	logger.Debugf("starting reconcile")
+	defer logger.Debugf("reconcile finished")
+
+	pc := new(tsapi.ProxyClass)
+	err = pcr.Get(ctx, req.NamespacedName, pc)
+	if apierrors.IsNotFound(err) {
+		logger.Debugf("ProxyClass not found, assuming it was deleted")
+		return reconcile.Result{}, nil
+	} else if err != nil {
+		return reconcile.Result{}, fmt.Errorf("failed to get tailscale.com ProxyClass: %w", err)
+	}
+	if !pc.DeletionTimestamp.IsZero() {
+		logger.Debugf("ProxyClass is being deleted, do nothing")
+		return reconcile.Result{}, nil
+	}
+	oldPCStatus := pc.Status.DeepCopy()
+	if errs := pcr.validate(pc); errs != nil {
+		msg := fmt.Sprintf(messageProxyClassInvalid, errs.ToAggregate().Error())
+		pcr.recorder.Event(pc, corev1.EventTypeWarning, reasonProxyClassInvalid, msg)
+		tsoperator.SetProxyClassCondition(pc, tsapi.ProxyClassready, metav1.ConditionFalse, reasonProxyClassInvalid, msg, pc.Generation, pcr.clock, logger)
+	} else {
+		tsoperator.SetProxyClassCondition(pc, tsapi.ProxyClassready, metav1.ConditionTrue, reasonProxyClassValid, reasonProxyClassValid, pc.Generation, pcr.clock, logger)
+	}
+	if !apiequality.Semantic.DeepEqual(oldPCStatus, pc.Status) {
+		if err := pcr.Client.Status().Update(ctx, pc); err != nil {
+			logger.Errorf("error updating ProxyClass status: %v", err)
+			return reconcile.Result{}, err
+		}
+	}
+	return reconcile.Result{}, nil
+}
+
+func (a *ProxyClassReconciler) validate(pc *tsapi.ProxyClass) (violations field.ErrorList) {
+	if sts := pc.Spec.StatefulSet; sts != nil {
+		if len(sts.Labels) > 0 {
+			if errs := metavalidation.ValidateLabels(sts.Labels, field.NewPath(".spec.statefulSet.labels")); errs != nil {
+				violations = append(violations, errs...)
+			}
+		}
+		if len(sts.Annotations) > 0 {
+			if errs := apivalidation.ValidateAnnotations(sts.Annotations, field.NewPath(".spec.statefulSet.annotations")); errs != nil {
+				violations = append(violations, errs...)
+			}
+		}
+		if pod := sts.Pod; pod != nil {
+			if len(pod.Labels) > 0 {
+				if errs := metavalidation.ValidateLabels(pod.Labels, field.NewPath(".spec.statefulSet.pod.labels")); errs != nil {
+					violations = append(violations, errs...)
+				}
+			}
+			if len(pod.Annotations) > 0 {
+				if errs := apivalidation.ValidateAnnotations(pod.Annotations, field.NewPath(".spec.statefulSet.pod.annotations")); errs != nil {
+					violations = append(violations, errs...)
+				}
+			}
+			if tc := pod.TailscaleContainer; tc != nil {
+				for _, e := range tc.Env {
+					if strings.HasPrefix(string(e.Name), "TS_") {
+						a.recorder.Event(pc, corev1.EventTypeWarning, reasonCustomTSEnvVar, fmt.Sprintf(messageCustomTSEnvVar, string(e.Name), "tailscale"))
+					}
+					if strings.EqualFold(string(e.Name), "EXPERIMENTAL_TS_CONFIGFILE_PATH") {
+						a.recorder.Event(pc, corev1.EventTypeWarning, reasonCustomTSEnvVar, fmt.Sprintf(messageCustomTSEnvVar, string(e.Name), "tailscale"))
+					}
+					if strings.EqualFold(string(e.Name), "EXPERIMENTAL_ALLOW_PROXYING_CLUSTER_TRAFFIC_VIA_INGRESS") {
+						a.recorder.Event(pc, corev1.EventTypeWarning, reasonCustomTSEnvVar, fmt.Sprintf(messageCustomTSEnvVar, string(e.Name), "tailscale"))
+					}
+				}
+			}
+		}
+	}
+	// We do not validate embedded fields (security context, resource
+	// requirements etc) as we inherit upstream validation for those fields.
+	// Invalid values would get rejected by upstream validations at apply
+	// time.
+	return violations
+}

cmd/k8s-operator/proxyclass_test.go

@@ -0,0 +1,98 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !plan9
+
+// tailscale-operator provides a way to expose services running in a Kubernetes
+// cluster to your Tailnet.
+package main
+
+import (
+	"testing"
+	"time"
+
+	"go.uber.org/zap"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/client-go/tools/record"
+	"sigs.k8s.io/controller-runtime/pkg/client/fake"
+	tsoperator "tailscale.com/k8s-operator"
+	tsapi "tailscale.com/k8s-operator/apis/v1alpha1"
+	"tailscale.com/tstest"
+)
+
+func TestProxyClass(t *testing.T) {
+	pc := &tsapi.ProxyClass{
+		TypeMeta: metav1.TypeMeta{Kind: "ProxyClass", APIVersion: "tailscale.com/v1alpha1"},
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "test",
+			// The apiserver is supposed to set the UID, but the fake client
+			// doesn't. So, set it explicitly because other code later depends
+			// on it being set.
+			UID: types.UID("1234-UID"),
+		},
+		Spec: tsapi.ProxyClassSpec{
+			StatefulSet: &tsapi.StatefulSet{
+				Labels:      map[string]string{"foo": "bar", "xyz1234": "abc567"},
+				Annotations: map[string]string{"foo.io/bar": "{'key': 'val1232'}"},
+				Pod: &tsapi.Pod{
+					Labels:             map[string]string{"foo": "bar", "xyz1234": "abc567"},
+					Annotations:        map[string]string{"foo.io/bar": "{'key': 'val1232'}"},
+					TailscaleContainer: &tsapi.Container{Env: []tsapi.Env{{Name: "FOO", Value: "BAR"}}},
+				},
+			},
+		},
+	}
+	fc := fake.NewClientBuilder().
+		WithScheme(tsapi.GlobalScheme).
+		WithObjects(pc).
+		WithStatusSubresource(pc).
+		Build()
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+	fr := record.NewFakeRecorder(3) // bump this if you expect a test case to throw more events
+	cl := tstest.NewClock(tstest.ClockOpts{})
+	pcr := &ProxyClassReconciler{
+		Client:   fc,
+		logger:   zl.Sugar(),
+		clock:    cl,
+		recorder: fr,
+	}
+
+	// 1. A valid ProxyClass resource gets its status updated to Ready.
+	expectReconciled(t, pcr, "", "test")
+	pc.Status.Conditions = append(pc.Status.Conditions, tsapi.ConnectorCondition{
+		Type:               tsapi.ProxyClassready,
+		Status:             metav1.ConditionTrue,
+		Reason:             reasonProxyClassValid,
+		Message:            reasonProxyClassValid,
+		LastTransitionTime: &metav1.Time{Time: cl.Now().Truncate(time.Second)},
+	})
+
+	expectEqual(t, fc, pc, nil)
+
+	// 2. An invalid ProxyClass resource gets its status updated to Invalid.
+	pc.Spec.StatefulSet.Labels["foo"] = "?!someVal"
+	mustUpdate(t, fc, "", "test", func(proxyClass *tsapi.ProxyClass) {
+		proxyClass.Spec.StatefulSet.Labels = pc.Spec.StatefulSet.Labels
+	})
+	expectReconciled(t, pcr, "", "test")
+	msg := `ProxyClass is not valid: .spec.statefulSet.labels: Invalid value: "?!someVal": a valid label must be an empty string or consist of alphanumeric characters, '-', '_' or '.', and must start and end with an alphanumeric character (e.g. 'MyValue',  or 'my_value',  or '12345', regex used for validation is '(([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9])?')`
+	tsoperator.SetProxyClassCondition(pc, tsapi.ProxyClassready, metav1.ConditionFalse, reasonProxyClassInvalid, msg, 0, cl, zl.Sugar())
+	expectEqual(t, fc, pc, nil)
+	expectedEvent := "Warning ProxyClassInvalid ProxyClass is not valid: .spec.statefulSet.labels: Invalid value: \"?!someVal\": a valid label must be an empty string or consist of alphanumeric characters, '-', '_' or '.', and must start and end with an alphanumeric character (e.g. 'MyValue',  or 'my_value',  or '12345', regex used for validation is '(([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9])?')"
+	expectEvents(t, fr, []string{expectedEvent})
+
+	// 2. An valid ProxyClass but with a Tailscale env vars set results in warning events.
+	mustUpdate(t, fc, "", "test", func(proxyClass *tsapi.ProxyClass) {
+		proxyClass.Spec.StatefulSet.Labels = nil // unset invalid labels from the previous test
+		proxyClass.Spec.StatefulSet.Pod.TailscaleContainer.Env = []tsapi.Env{{Name: "TS_USERSPACE", Value: "true"}, {Name: "EXPERIMENTAL_TS_CONFIGFILE_PATH"}, {Name: "EXPERIMENTAL_ALLOW_PROXYING_CLUSTER_TRAFFIC_VIA_INGRESS"}}
+	})
+	expectedEvents := []string{"Warning CustomTSEnvVar ProxyClass overrides the default value for TS_USERSPACE env var for tailscale container. Running with custom values for Tailscale env vars is not recommended and might break in the future.",
+		"Warning CustomTSEnvVar ProxyClass overrides the default value for EXPERIMENTAL_TS_CONFIGFILE_PATH env var for tailscale container. Running with custom values for Tailscale env vars is not recommended and might break in the future.",
+		"Warning CustomTSEnvVar ProxyClass overrides the default value for EXPERIMENTAL_ALLOW_PROXYING_CLUSTER_TRAFFIC_VIA_INGRESS env var for tailscale container. Running with custom values for Tailscale env vars is not recommended and might break in the future."}
+	expectReconciled(t, pcr, "", "test")
+	expectEvents(t, fr, expectedEvents)
+}

cmd/k8s-operator/sts.go

@@ -14,6 +14,7 @@ import (
 	"fmt"
 	"net/http"
 	"os"
+	"slices"
 	"strings"
 
 	"go.uber.org/zap"
@@ -22,25 +23,38 @@ import (
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apiserver/pkg/storage/names"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/yaml"
 	"tailscale.com/client/tailscale"
 	"tailscale.com/ipn"
+	kubeutils "tailscale.com/k8s-operator"
+	tsoperator "tailscale.com/k8s-operator"
+	tsapi "tailscale.com/k8s-operator/apis/v1alpha1"
 	"tailscale.com/net/netutil"
 	"tailscale.com/tailcfg"
-	"tailscale.com/tsnet"
 	"tailscale.com/types/opt"
+	"tailscale.com/types/ptr"
 	"tailscale.com/util/dnsname"
 	"tailscale.com/util/mak"
 )
 
 const (
+	// Labels that the operator sets on StatefulSets and Pods. If you add a
+	// new label here, do also add it to tailscaleManagedLabels var to
+	// ensure that it does not get overwritten by ProxyClass configuration.
 	LabelManaged         = "tailscale.com/managed"
 	LabelParentType      = "tailscale.com/parent-resource-type"
 	LabelParentName      = "tailscale.com/parent-resource"
 	LabelParentNamespace = "tailscale.com/parent-resource-ns"
 
+	// LabelProxyClass can be set by users on Connectors, tailscale
+	// Ingresses and Services that define cluster ingress or cluster egress,
+	// to specify that configuration in this ProxyClass should be applied to
+	// resources created for the Connector, Ingress or Service.
+	LabelProxyClass = "tailscale.com/proxy-class"
+
 	FinalizerName = "tailscale.com/finalizer"
 
 	// Annotations settable by users on services.
@@ -55,18 +69,37 @@ const (
 	// Annotations settable by users on ingresses.
 	AnnotationFunnel = "tailscale.com/funnel"
 
+	// If set to true, set up iptables/nftables rules in the proxy forward
+	// cluster traffic to the tailnet IP of that proxy. This can only be set
+	// on an Ingress. This is useful in cases where a cluster target needs
+	// to be able to reach a cluster workload exposed to tailnet via Ingress
+	// using the same hostname as a tailnet workload (in this case, the
+	// MagicDNS name of the ingress proxy). This annotation is experimental.
+	// If it is set to true, the proxy set up for Ingress, will run
+	// tailscale in non-userspace, with NET_ADMIN cap for tailscale
+	// container and will also run a privileged init container that enables
+	// forwarding.
+	// Eventually this behaviour might become the default.
+	AnnotationExperimentalForwardClusterTrafficViaL7IngresProxy = "tailscale.com/experimental-forward-cluster-traffic-via-ingress"
+
 	// Annotations set by the operator on pods to trigger restarts when the
-	// hostname, IP, FQDN or tailscaled config changes.
+	// hostname, IP, FQDN or tailscaled config changes. If you add a new
+	// annotation here, also add it to tailscaleManagedAnnotations var to
+	// ensure that it does not get removed when a ProxyClass configuration
+	// is applied.
 	podAnnotationLastSetClusterIP         = "tailscale.com/operator-last-set-cluster-ip"
-	podAnnotationLastSetHostname          = "tailscale.com/operator-last-set-hostname"
+	podAnnotationLastSetClusterDNSName    = "tailscale.com/operator-last-set-cluster-dns-name"
 	podAnnotationLastSetTailnetTargetIP   = "tailscale.com/operator-last-set-ts-tailnet-target-ip"
 	podAnnotationLastSetTailnetTargetFQDN = "tailscale.com/operator-last-set-ts-tailnet-target-fqdn"
 	// podAnnotationLastSetConfigFileHash is sha256 hash of the current tailscaled configuration contents.
 	podAnnotationLastSetConfigFileHash = "tailscale.com/operator-last-set-config-file-hash"
+)
 
-	// tailscaledConfigKey is the name of the key in proxy Secret Data that
-	// holds the tailscaled config contents.
-	tailscaledConfigKey = "tailscaled"
+var (
+	// tailscaleManagedLabels are label keys that tailscale operator sets on StatefulSets and Pods.
+	tailscaleManagedLabels = []string{LabelManaged, LabelParentType, LabelParentName, LabelParentNamespace, "app"}
+	// tailscaleManagedAnnotations are annotation keys that tailscale operator sets on StatefulSets and Pods.
+	tailscaleManagedAnnotations = []string{podAnnotationLastSetClusterIP, podAnnotationLastSetTailnetTargetIP, podAnnotationLastSetTailnetTargetFQDN, podAnnotationLastSetConfigFileHash}
 )
 
 type tailscaleSTSConfig struct {
@@ -74,8 +107,12 @@ type tailscaleSTSConfig struct {
 	ParentResourceUID   string
 	ChildResourceLabels map[string]string
 
-	ServeConfig     *ipn.ServeConfig
-	ClusterTargetIP string // ingress target
+	ServeConfig          *ipn.ServeConfig // if serve config is set, this is a proxy for Ingress
+	ClusterTargetIP      string           // ingress target IP
+	ClusterTargetDNSName string           // ingress target DNS name
+	// If set to true, operator should configure containerboot to forward
+	// cluster traffic via the proxy set up for Kubernetes Ingress.
+	ForwardClusterTrafficViaL7IngressProxy bool
 
 	TailnetTargetIP string // egress target IP
 
@@ -87,6 +124,8 @@ type tailscaleSTSConfig struct {
 	// Connector specifies a configuration of a Connector instance if that's
 	// what this StatefulSet should be created for.
 	Connector *connector
+
+	ProxyClass string
 }
 
 type connector struct {
@@ -95,10 +134,13 @@ type connector struct {
 	// isExitNode defines whether this Connector should act as an exit node.
 	isExitNode bool
 }
+type tsnetServer interface {
+	CertDomains() []string
+}
 
 type tailscaleSTSReconciler struct {
 	client.Client
-	tsnetServer            *tsnet.Server
+	tsnetServer            tsnetServer
 	tsClient               tsClient
 	defaultTags            []string
 	operatorNamespace      string
@@ -129,11 +171,11 @@ func (a *tailscaleSTSReconciler) Provision(ctx context.Context, logger *zap.Suga
 		return nil, fmt.Errorf("failed to reconcile headless service: %w", err)
 	}
 
-	secretName, tsConfigHash, err := a.createOrGetSecret(ctx, logger, sts, hsvc)
+	secretName, tsConfigHash, configs, err := a.createOrGetSecret(ctx, logger, sts, hsvc)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create or get API key secret: %w", err)
 	}
-	_, err = a.reconcileSTS(ctx, logger, sts, hsvc, secretName, tsConfigHash)
+	_, err = a.reconcileSTS(ctx, logger, sts, hsvc, secretName, tsConfigHash, configs)
 	if err != nil {
 		return nil, fmt.Errorf("failed to reconcile statefulset: %w", err)
 	}
@@ -246,7 +288,7 @@ func (a *tailscaleSTSReconciler) reconcileHeadlessService(ctx context.Context, l
 	return createOrUpdate(ctx, a.Client, a.operatorNamespace, hsvc, func(svc *corev1.Service) { svc.Spec = hsvc.Spec })
 }
 
-func (a *tailscaleSTSReconciler) createOrGetSecret(ctx context.Context, logger *zap.SugaredLogger, stsC *tailscaleSTSConfig, hsvc *corev1.Service) (string, string, error) {
+func (a *tailscaleSTSReconciler) createOrGetSecret(ctx context.Context, logger *zap.SugaredLogger, stsC *tailscaleSTSConfig, hsvc *corev1.Service) (secretName, hash string, configs tailscaleConfigs, _ error) {
 	secret := &corev1.Secret{
 		ObjectMeta: metav1.ObjectMeta{
 			// Hardcode a -0 suffix so that in future, if we support
@@ -262,25 +304,23 @@ func (a *tailscaleSTSReconciler) createOrGetSecret(ctx context.Context, logger *
 		logger.Debugf("secret %s/%s already exists", secret.GetNamespace(), secret.GetName())
 		orig = secret.DeepCopy()
 	} else if !apierrors.IsNotFound(err) {
-		return "", "", err
+		return "", "", nil, err
 	}
 
-	var (
-		authKey, hash string
-	)
+	var authKey string
 	if orig == nil {
-		// Secret doesn't exist yet, create one. Initially it contains
-		// only the Tailscale authkey, but once Tailscale starts it'll
-		// also store the daemon state.
+		// Initially it contains only tailscaled config, but when the
+		// proxy starts, it will also store there the state, certs and
+		// ACME account key.
 		sts, err := getSingleObject[appsv1.StatefulSet](ctx, a.Client, a.operatorNamespace, stsC.ChildResourceLabels)
 		if err != nil {
-			return "", "", err
+			return "", "", nil, err
 		}
 		if sts != nil {
 			// StatefulSet exists, so we have already created the secret.
 			// If the secret is missing, they should delete the StatefulSet.
 			logger.Errorf("Tailscale proxy secret doesn't exist, but the corresponding StatefulSet %s/%s already does. Something is wrong, please delete the StatefulSet.", sts.GetNamespace(), sts.GetName())
-			return "", "", nil
+			return "", "", nil, nil
 		}
 		// Create API Key secret which is going to be used by the statefulset
 		// to authenticate with Tailscale.
@@ -291,40 +331,66 @@ func (a *tailscaleSTSReconciler) createOrGetSecret(ctx context.Context, logger *
 		}
 		authKey, err = a.newAuthKey(ctx, tags)
 		if err != nil {
-			return "", "", err
+			return "", "", nil, err
 		}
 	}
-	if !shouldDoTailscaledDeclarativeConfig(stsC) && authKey != "" {
-		mak.Set(&secret.StringData, "authkey", authKey)
+	configs, err := tailscaledConfig(stsC, authKey, orig)
+	if err != nil {
+		return "", "", nil, fmt.Errorf("error creating tailscaled config: %w", err)
 	}
-	if shouldDoTailscaledDeclarativeConfig(stsC) {
-		confFileBytes, h, err := tailscaledConfig(stsC, authKey, orig)
+	hash, err = tailscaledConfigHash(configs)
+	if err != nil {
+		return "", "", nil, fmt.Errorf("error calculating hash of tailscaled configs: %w", err)
+	}
+
+	latest := tailcfg.CapabilityVersion(-1)
+	var latestConfig ipn.ConfigVAlpha
+	for key, val := range configs {
+		fn := kubeutils.TailscaledConfigFileNameForCap(key)
+		b, err := json.Marshal(val)
 		if err != nil {
-			return "", "", fmt.Errorf("error creating tailscaled config: %w", err)
+			return "", "", nil, fmt.Errorf("error marshalling tailscaled config: %w", err)
+		}
+		mak.Set(&secret.StringData, fn, string(b))
+		if key > latest {
+			latest = key
+			latestConfig = val
 		}
-		hash = h
-		mak.Set(&secret.StringData, tailscaledConfigKey, string(confFileBytes))
 	}
+
 	if stsC.ServeConfig != nil {
 		j, err := json.Marshal(stsC.ServeConfig)
 		if err != nil {
-			return "", "", err
+			return "", "", nil, err
 		}
 		mak.Set(&secret.StringData, "serve-config", string(j))
 	}
 
 	if orig != nil {
-		logger.Debugf("patching existing state Secret with values %s", secret.Data[tailscaledConfigKey])
+		logger.Debugf("patching the existing proxy Secret with tailscaled config %s", sanitizeConfigBytes(latestConfig))
 		if err := a.Patch(ctx, secret, client.MergeFrom(orig)); err != nil {
-			return "", "", err
+			return "", "", nil, err
 		}
 	} else {
-		logger.Debugf("creating new state Secret with authkey %s", secret.Data[tailscaledConfigKey])
+		logger.Debugf("creating a new Secret for the proxy with tailscaled config %s", sanitizeConfigBytes(latestConfig))
 		if err := a.Create(ctx, secret); err != nil {
-			return "", "", err
+			return "", "", nil, err
 		}
 	}
-	return secret.Name, hash, nil
+	return secret.Name, hash, configs, nil
+}
+
+// sanitizeConfigBytes returns ipn.ConfigVAlpha in string form with redacted
+// auth key.
+func sanitizeConfigBytes(c ipn.ConfigVAlpha) string {
+	if c.AuthKey != nil {
+		c.AuthKey = ptr.To("**redacted**")
+	}
+	sanitizedBytes, err := json.Marshal(c)
+	if err != nil {
+		return "invalid config"
+	}
+	return string(sanitizedBytes)
 }
 
 // DeviceInfo returns the device ID and hostname for the Tailscale device
@@ -379,11 +445,11 @@ var proxyYaml []byte
 //go:embed deploy/manifests/userspace-proxy.yaml
 var userspaceProxyYaml []byte
 
-func (a *tailscaleSTSReconciler) reconcileSTS(ctx context.Context, logger *zap.SugaredLogger, sts *tailscaleSTSConfig, headlessSvc *corev1.Service, proxySecret, tsConfigHash string) (*appsv1.StatefulSet, error) {
-	var ss appsv1.StatefulSet
-	if sts.ServeConfig != nil {
+func (a *tailscaleSTSReconciler) reconcileSTS(ctx context.Context, logger *zap.SugaredLogger, sts *tailscaleSTSConfig, headlessSvc *corev1.Service, proxySecret, tsConfigHash string, configs map[tailcfg.CapabilityVersion]ipn.ConfigVAlpha) (*appsv1.StatefulSet, error) {
+	ss := new(appsv1.StatefulSet)
+	if sts.ServeConfig != nil && sts.ForwardClusterTrafficViaL7IngressProxy != true { // If forwarding cluster traffic via is required we need non-userspace + NET_ADMIN + forwarding
 		if err := yaml.Unmarshal(userspaceProxyYaml, &ss); err != nil {
-			return nil, fmt.Errorf("failed to unmarshal proxy spec: %w", err)
+			return nil, fmt.Errorf("failed to unmarshal userspace proxy spec: %v", err)
 		}
 	} else {
 		if err := yaml.Unmarshal(proxyYaml, &ss); err != nil {
@@ -397,12 +463,25 @@ func (a *tailscaleSTSReconciler) reconcileSTS(ctx context.Context, logger *zap.S
 			}
 		}
 	}
-	container := &ss.Spec.Template.Spec.Containers[0]
+	pod := &ss.Spec.Template
+	container := &pod.Spec.Containers[0]
+	proxyClass := new(tsapi.ProxyClass)
+	if sts.ProxyClass != "" {
+		if err := a.Get(ctx, types.NamespacedName{Name: sts.ProxyClass}, proxyClass); err != nil {
+			return nil, fmt.Errorf("failed to get ProxyClass: %w", err)
+		}
+		if !tsoperator.ProxyClassIsReady(proxyClass) {
+			logger.Infof("ProxyClass %s specified for the proxy, but it is not (yet) in a ready state, waiting..")
+			return nil, nil
+		}
+	}
 	container.Image = a.proxyImage
 	ss.ObjectMeta = metav1.ObjectMeta{
 		Name:      headlessSvc.Name,
 		Namespace: a.operatorNamespace,
-		Labels:    sts.ChildResourceLabels,
+	}
+	for key, val := range sts.ChildResourceLabels {
+		mak.Set(&ss.ObjectMeta.Labels, key, val)
 	}
 	ss.Spec.ServiceName = headlessSvc.Name
 	ss.Spec.Selector = &metav1.LabelSelector{
@@ -410,9 +489,9 @@ func (a *tailscaleSTSReconciler) reconcileSTS(ctx context.Context, logger *zap.S
 			"app": sts.ParentResourceUID,
 		},
 	}
-	mak.Set(&ss.Spec.Template.Labels, "app", sts.ParentResourceUID)
+	mak.Set(&pod.Labels, "app", sts.ParentResourceUID)
 	for key, val := range sts.ChildResourceLabels {
-		ss.Spec.Template.Labels[key] = val // sync StatefulSet labels to Pod to make it easier for users to select the Pod
+		pod.Labels[key] = val // sync StatefulSet labels to Pod to make it easier for users to select the Pod
 	}
 
 	// Generic containerboot configuration options.
@@ -421,43 +500,40 @@ func (a *tailscaleSTSReconciler) reconcileSTS(ctx context.Context, logger *zap.S
 			Name:  "TS_KUBE_SECRET",
 			Value: proxySecret,
 		},
-	)
-	if !shouldDoTailscaledDeclarativeConfig(sts) {
-		container.Env = append(container.Env, corev1.EnvVar{
-			Name:  "TS_HOSTNAME",
-			Value: sts.Hostname,
-		})
-		// containerboot currently doesn't have a way to re-read the hostname/ip as
-		// it is passed via an environment variable. So we need to restart the
-		// container when the value changes. We do this by adding an annotation to
-		// the pod template that contains the last value we set.
-		mak.Set(&ss.Spec.Template.Annotations, podAnnotationLastSetHostname, sts.Hostname)
-	}
-	// Configure containeboot to run tailscaled with a configfile read from the state Secret.
-	if shouldDoTailscaledDeclarativeConfig(sts) {
-		mak.Set(&ss.Spec.Template.Annotations, podAnnotationLastSetConfigFileHash, tsConfigHash)
-		ss.Spec.Template.Spec.Volumes = append(ss.Spec.Template.Spec.Volumes, corev1.Volume{
-			Name: "tailscaledconfig",
-			VolumeSource: corev1.VolumeSource{
-				Secret: &corev1.SecretVolumeSource{
-					SecretName: proxySecret,
-					Items: []corev1.KeyToPath{{
-						Key:  tailscaledConfigKey,
-						Path: tailscaledConfigKey,
-					}},
-				},
-			},
-		})
-		container.VolumeMounts = append(container.VolumeMounts, corev1.VolumeMount{
-			Name:      "tailscaledconfig",
-			ReadOnly:  true,
-			MountPath: "/etc/tsconfig",
-		})
-		container.Env = append(container.Env, corev1.EnvVar{
+		corev1.EnvVar{
+			// Old tailscaled config key is still used for backwards compatibility.
 			Name:  "EXPERIMENTAL_TS_CONFIGFILE_PATH",
 			Value: "/etc/tsconfig/tailscaled",
+		},
+		corev1.EnvVar{
+			// New style is in the form of cap-<capability-version>.hujson.
+			Name:  "TS_EXPERIMENTAL_VERSIONED_CONFIG_DIR",
+			Value: "/etc/tsconfig",
+		},
+	)
+	if sts.ForwardClusterTrafficViaL7IngressProxy {
+		container.Env = append(container.Env, corev1.EnvVar{
+			Name:  "EXPERIMENTAL_ALLOW_PROXYING_CLUSTER_TRAFFIC_VIA_INGRESS",
+			Value: "true",
 		})
 	}
+	// Configure containeboot to run tailscaled with a configfile read from the state Secret.
+	mak.Set(&ss.Spec.Template.Annotations, podAnnotationLastSetConfigFileHash, tsConfigHash)
+
+	configVolume := corev1.Volume{
+		Name: "tailscaledconfig",
+		VolumeSource: corev1.VolumeSource{
+			Secret: &corev1.SecretVolumeSource{
+				SecretName: proxySecret,
+			},
+		},
+	}
+	pod.Spec.Volumes = append(ss.Spec.Template.Spec.Volumes, configVolume)
+	container.VolumeMounts = append(container.VolumeMounts, corev1.VolumeMount{
+		Name:      "tailscaledconfig",
+		ReadOnly:  true,
+		MountPath: "/etc/tsconfig",
+	})
 
 	if a.tsFirewallMode != "" {
 		container.Env = append(container.Env, corev1.EnvVar{
@@ -465,7 +541,7 @@ func (a *tailscaleSTSReconciler) reconcileSTS(ctx context.Context, logger *zap.S
 			Value: a.tsFirewallMode,
 		})
 	}
-	ss.Spec.Template.Spec.PriorityClassName = a.proxyPriorityClassName
+	pod.Spec.PriorityClassName = a.proxyPriorityClassName
 
 	// Ingress/egress proxy configuration options.
 	if sts.ClusterTargetIP != "" {
@@ -474,6 +550,12 @@ func (a *tailscaleSTSReconciler) reconcileSTS(ctx context.Context, logger *zap.S
 			Value: sts.ClusterTargetIP,
 		})
 		mak.Set(&ss.Spec.Template.Annotations, podAnnotationLastSetClusterIP, sts.ClusterTargetIP)
+	} else if sts.ClusterTargetDNSName != "" {
+		container.Env = append(container.Env, corev1.EnvVar{
+			Name:  "TS_EXPERIMENTAL_DEST_DNS_NAME",
+			Value: sts.ClusterTargetDNSName,
+		})
+		mak.Set(&ss.Spec.Template.Annotations, podAnnotationLastSetClusterDNSName, sts.ClusterTargetDNSName)
 	} else if sts.TailnetTargetIP != "" {
 		container.Env = append(container.Env, corev1.EnvVar{
 			Name:  "TS_TAILNET_TARGET_IP",
@@ -496,58 +578,229 @@ func (a *tailscaleSTSReconciler) reconcileSTS(ctx context.Context, logger *zap.S
 			ReadOnly:  true,
 			MountPath: "/etc/tailscaled",
 		})
-		ss.Spec.Template.Spec.Volumes = append(ss.Spec.Template.Spec.Volumes, corev1.Volume{
+		pod.Spec.Volumes = append(ss.Spec.Template.Spec.Volumes, corev1.Volume{
 			Name: "serve-config",
 			VolumeSource: corev1.VolumeSource{
 				Secret: &corev1.SecretVolumeSource{
 					SecretName: proxySecret,
-					Items: []corev1.KeyToPath{{
-						Key:  "serve-config",
-						Path: "serve-config",
-					}},
+					Items:      []corev1.KeyToPath{{Key: "serve-config", Path: "serve-config"}},
 				},
 			},
 		})
 	}
 	logger.Debugf("reconciling statefulset %s/%s", ss.GetNamespace(), ss.GetName())
-	return createOrUpdate(ctx, a.Client, a.operatorNamespace, &ss, func(s *appsv1.StatefulSet) { s.Spec = ss.Spec })
+	if sts.ProxyClass != "" {
+		logger.Debugf("configuring proxy resources with ProxyClass %s", sts.ProxyClass)
+		ss = applyProxyClassToStatefulSet(proxyClass, ss, sts, logger)
+	}
+	updateSS := func(s *appsv1.StatefulSet) {
+		s.Spec = ss.Spec
+		s.ObjectMeta.Labels = ss.Labels
+		s.ObjectMeta.Annotations = ss.Annotations
+	}
+	return createOrUpdate(ctx, a.Client, a.operatorNamespace, ss, updateSS)
+}
+
+// mergeStatefulSetLabelsOrAnnots returns a map that contains all keys/values
+// present in 'custom' map as well as those keys/values from the current map
+// whose keys are present in the 'managed' map. The reason why this merge is
+// necessary is to ensure that labels/annotations applied from a ProxyClass get removed
+// if they are removed from a ProxyClass or if the ProxyClass no longer applies
+// to this StatefulSet whilst any tailscale managed labels/annotations remain present.
+func mergeStatefulSetLabelsOrAnnots(current, custom map[string]string, managed []string) map[string]string {
+	if custom == nil {
+		custom = make(map[string]string)
+	}
+	if current == nil {
+		return custom
+	}
+	for key, val := range current {
+		if slices.Contains(managed, key) {
+			custom[key] = val
+		}
+	}
+	return custom
+}
+
+func applyProxyClassToStatefulSet(pc *tsapi.ProxyClass, ss *appsv1.StatefulSet, stsCfg *tailscaleSTSConfig, logger *zap.SugaredLogger) *appsv1.StatefulSet {
+	if pc == nil || ss == nil {
+		return ss
+	}
+	if pc.Spec.Metrics != nil && pc.Spec.Metrics.Enable {
+		if stsCfg.TailnetTargetFQDN == "" && stsCfg.TailnetTargetIP == "" && !stsCfg.ForwardClusterTrafficViaL7IngressProxy {
+			enableMetrics(ss, pc)
+		} else if stsCfg.ForwardClusterTrafficViaL7IngressProxy {
+			// TODO (irbekrm): fix this
+			// For Ingress proxies that have been configured with
+			// tailscale.com/experimental-forward-cluster-traffic-via-ingress
+			// annotation, all cluster traffic is forwarded to the
+			// Ingress backend(s).
+			logger.Info("ProxyClass specifies that metrics should be enabled, but this is currently not supported for Ingress proxies that accept cluster traffic.")
+		} else {
+			// TODO (irbekrm): fix this
+			// For egress proxies, currently all cluster traffic is forwarded to the tailnet target.
+			logger.Info("ProxyClass specifies that metrics should be enabled, but this is currently not supported for Ingress proxies that accept cluster traffic.")
+		}
+	}
+
+	if pc.Spec.StatefulSet == nil {
+		return ss
+	}
+
+	// Update StatefulSet metadata.
+	if wantsSSLabels := pc.Spec.StatefulSet.Labels; len(wantsSSLabels) > 0 {
+		ss.ObjectMeta.Labels = mergeStatefulSetLabelsOrAnnots(ss.ObjectMeta.Labels, wantsSSLabels, tailscaleManagedLabels)
+	}
+	if wantsSSAnnots := pc.Spec.StatefulSet.Annotations; len(wantsSSAnnots) > 0 {
+		ss.ObjectMeta.Annotations = mergeStatefulSetLabelsOrAnnots(ss.ObjectMeta.Annotations, wantsSSAnnots, tailscaleManagedAnnotations)
+	}
+
+	// Update Pod fields.
+	if pc.Spec.StatefulSet.Pod == nil {
+		return ss
+	}
+	wantsPod := pc.Spec.StatefulSet.Pod
+	if wantsPodLabels := wantsPod.Labels; len(wantsPodLabels) > 0 {
+		ss.Spec.Template.ObjectMeta.Labels = mergeStatefulSetLabelsOrAnnots(ss.Spec.Template.ObjectMeta.Labels, wantsPodLabels, tailscaleManagedLabels)
+	}
+	if wantsPodAnnots := wantsPod.Annotations; len(wantsPodAnnots) > 0 {
+		ss.Spec.Template.ObjectMeta.Annotations = mergeStatefulSetLabelsOrAnnots(ss.Spec.Template.ObjectMeta.Annotations, wantsPodAnnots, tailscaleManagedAnnotations)
+	}
+	ss.Spec.Template.Spec.SecurityContext = wantsPod.SecurityContext
+	ss.Spec.Template.Spec.ImagePullSecrets = wantsPod.ImagePullSecrets
+	ss.Spec.Template.Spec.NodeName = wantsPod.NodeName
+	ss.Spec.Template.Spec.NodeSelector = wantsPod.NodeSelector
+	ss.Spec.Template.Spec.Affinity = wantsPod.Affinity
+	ss.Spec.Template.Spec.Tolerations = wantsPod.Tolerations
+
+	// Update containers.
+	updateContainer := func(overlay *tsapi.Container, base corev1.Container) corev1.Container {
+		if overlay == nil {
+			return base
+		}
+		if overlay.SecurityContext != nil {
+			base.SecurityContext = overlay.SecurityContext
+		}
+		base.Resources = overlay.Resources
+		for _, e := range overlay.Env {
+			// Env vars configured via ProxyClass might override env
+			// vars that have been specified by the operator, i.e
+			// TS_USERSPACE. The intended behaviour is to allow this
+			// and in practice it works without explicitly removing
+			// the operator configured value here as a later value
+			// in the env var list overrides an earlier one.
+			base.Env = append(base.Env, corev1.EnvVar{Name: string(e.Name), Value: e.Value})
+		}
+		return base
+	}
+	for i, c := range ss.Spec.Template.Spec.Containers {
+		if c.Name == "tailscale" {
+			ss.Spec.Template.Spec.Containers[i] = updateContainer(wantsPod.TailscaleContainer, ss.Spec.Template.Spec.Containers[i])
+			break
+		}
+	}
+	if initContainers := ss.Spec.Template.Spec.InitContainers; len(initContainers) > 0 {
+		for i, c := range initContainers {
+			if c.Name == "sysctler" {
+				ss.Spec.Template.Spec.InitContainers[i] = updateContainer(wantsPod.TailscaleInitContainer, initContainers[i])
+				break
+			}
+		}
+	}
+	return ss
+}
+
+func enableMetrics(ss *appsv1.StatefulSet, pc *tsapi.ProxyClass) {
+	for i, c := range ss.Spec.Template.Spec.Containers {
+		if c.Name == "tailscale" {
+			// Serve metrics on on <pod-ip>:9001/debug/metrics. If
+			// we didn't specify Pod IP here, the proxy would, in
+			// some cases, also listen to its Tailscale IP- we don't
+			// want folks to start relying on this side-effect as a
+			// feature.
+			ss.Spec.Template.Spec.Containers[i].Env = append(ss.Spec.Template.Spec.Containers[i].Env, corev1.EnvVar{Name: "TS_TAILSCALED_EXTRA_ARGS", Value: "--debug=$(POD_IP):9001"})
+			ss.Spec.Template.Spec.Containers[i].Ports = append(ss.Spec.Template.Spec.Containers[i].Ports, corev1.ContainerPort{Name: "metrics", Protocol: "TCP", HostPort: 9001, ContainerPort: 9001})
+			break
+		}
+	}
+}
+
+func readAuthKey(secret *corev1.Secret, key string) (*string, error) {
+	origConf := &ipn.ConfigVAlpha{}
+	if err := json.Unmarshal([]byte(secret.Data[key]), origConf); err != nil {
+		return nil, fmt.Errorf("error unmarshaling previous tailscaled config in %q: %w", key, err)
+	}
+	return origConf.AuthKey, nil
 }
 
 // tailscaledConfig takes a proxy config, a newly generated auth key if
 // generated and a Secret with the previous proxy state and auth key and
-// produces returns tailscaled configuration and a hash of that configuration.
-func tailscaledConfig(stsC *tailscaleSTSConfig, newAuthkey string, oldSecret *corev1.Secret) ([]byte, string, error) {
-	conf := ipn.ConfigVAlpha{
-		Version:   "alpha0",
-		AcceptDNS: "false",
-		Locked:    "false",
-		Hostname:  &stsC.Hostname,
+// returns tailscaled configuration and a hash of that configuration.
+//
+// As of 2024-05-09 it also returns legacy tailscaled config without the
+// later added NoStatefulFilter field to support proxies older than cap95.
+// TODO (irbekrm): remove the legacy config once we no longer need to support
+// versions older than cap94,
+// https://tailscale.com/kb/1236/kubernetes-operator#operator-and-proxies
+func tailscaledConfig(stsC *tailscaleSTSConfig, newAuthkey string, oldSecret *corev1.Secret) (tailscaleConfigs, error) {
+	conf := &ipn.ConfigVAlpha{
+		Version:             "alpha0",
+		AcceptDNS:           "false",
+		AcceptRoutes:        "false", // AcceptRoutes defaults to true
+		Locked:              "false",
+		Hostname:            &stsC.Hostname,
+		NoStatefulFiltering: "false",
+	}
+
+	// For egress proxies only, we need to ensure that stateful filtering is
+	// not in place so that traffic from cluster can be forwarded via
+	// Tailscale IPs.
+	if stsC.TailnetTargetFQDN != "" || stsC.TailnetTargetIP != "" {
+		conf.NoStatefulFiltering = "true"
 	}
 	if stsC.Connector != nil {
 		routes, err := netutil.CalcAdvertiseRoutes(stsC.Connector.routes, stsC.Connector.isExitNode)
 		if err != nil {
-			return nil, "", fmt.Errorf("error calculating routes: %w", err)
+			return nil, fmt.Errorf("error calculating routes: %w", err)
 		}
 		conf.AdvertiseRoutes = routes
 	}
 	if newAuthkey != "" {
 		conf.AuthKey = &newAuthkey
-	} else if oldSecret != nil && len(oldSecret.Data[tailscaledConfigKey]) > 0 { // write to StringData, read from Data as StringData is write-only
-		origConf := &ipn.ConfigVAlpha{}
-		if err := json.Unmarshal([]byte(oldSecret.Data[tailscaledConfigKey]), origConf); err != nil {
-			return nil, "", fmt.Errorf("error unmarshaling previous tailscaled config: %w", err)
+	} else if oldSecret != nil {
+		var err error
+		latest := tailcfg.CapabilityVersion(-1)
+		latestStr := ""
+		for k, data := range oldSecret.Data {
+			// write to StringData, read from Data as StringData is write-only
+			if len(data) == 0 {
+				continue
+			}
+			v, err := kubeutils.CapVerFromFileName(k)
+			if err != nil {
+				continue
+			}
+			if v > latest {
+				latestStr = k
+				latest = v
+			}
+		}
+		// Allow for configs that don't contain an auth key. Perhaps
+		// users have some mechanisms to delete them. Auth key is
+		// normally not needed after the initial login.
+		if latestStr != "" {
+			conf.AuthKey, err = readAuthKey(oldSecret, latestStr)
+			if err != nil {
+				return nil, err
+			}
 		}
-		conf.AuthKey = origConf.AuthKey
 	}
-	confFileBytes, err := json.Marshal(conf)
-	if err != nil {
-		return nil, "", fmt.Errorf("error marshaling tailscaled config : %w", err)
-	}
-	hash, err := hashBytes(confFileBytes)
-	if err != nil {
-		return nil, "", fmt.Errorf("error calculating config hash: %w", err)
-	}
-	return confFileBytes, hash, nil
+	capVerConfigs := make(map[tailcfg.CapabilityVersion]ipn.ConfigVAlpha)
+	capVerConfigs[95] = *conf
+	// legacy config should not contain NoStatefulFiltering field.
+	conf.NoStatefulFiltering.Clear()
+	capVerConfigs[94] = *conf
+	return capVerConfigs, nil
 }
 
 // ptrObject is a type constraint for pointer types that implement
@@ -557,7 +810,9 @@ type ptrObject[T any] interface {
 	*T
 }
 
-// hashBytes produces a hash for the provided bytes that is the same across
+type tailscaleConfigs map[tailcfg.CapabilityVersion]ipn.ConfigVAlpha
+
+// hashBytes produces a hash for the provided tailscaled config that is the same across
 // different invocations of this code. We do not use the
 // tailscale.com/deephash.Hash here because that produces a different hash for
 // the same value in different tailscale builds. The hash we are producing here
@@ -566,10 +821,13 @@ type ptrObject[T any] interface {
 // thing that changed is operator version (the hash is also exposed to users via
 // an annotation and might be confusing if it changes without the config having
 // changed).
-func hashBytes(b []byte) (string, error) {
-	h := sha256.New()
-	_, err := h.Write(b)
+func tailscaledConfigHash(c tailscaleConfigs) (string, error) {
+	b, err := json.Marshal(c)
 	if err != nil {
+		return "", fmt.Errorf("error marshalling tailscaled configs: %w", err)
+	}
+	h := sha256.New()
+	if _, err = h.Write(b); err != nil {
 		return "", fmt.Errorf("error calculating hash: %w", err)
 	}
 	return fmt.Sprintf("%x", h.Sum(nil)), nil
@@ -678,10 +936,3 @@ func nameForService(svc *corev1.Service) (string, error) {
 func isValidFirewallMode(m string) bool {
 	return m == "auto" || m == "nftables" || m == "iptables"
 }
-
-// shouldDoTailscaledDeclarativeConfig determines whether the proxy instance
-// should be configured to run tailscaled only with a all config opts passed to
-// tailscaled.
-func shouldDoTailscaledDeclarativeConfig(stsC *tailscaleSTSConfig) bool {
-	return stsC.Connector != nil
-}

cmd/k8s-operator/sts_test.go

@@ -6,10 +6,21 @@
 package main
 
 import (
+	_ "embed"
 	"fmt"
+	"reflect"
 	"regexp"
 	"strings"
 	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"go.uber.org/zap"
+	appsv1 "k8s.io/api/apps/v1"
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/resource"
+	"sigs.k8s.io/yaml"
+	tsapi "tailscale.com/k8s-operator/apis/v1alpha1"
+	"tailscale.com/types/ptr"
 )
 
 // Test_statefulSetNameBase tests that parent name portion in a StatefulSet name
@@ -39,3 +50,272 @@ func Test_statefulSetNameBase(t *testing.T) {
 		}
 	}
 }
+
+func Test_applyProxyClassToStatefulSet(t *testing.T) {
+	zl, err := zap.NewDevelopment()
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Setup
+	proxyClassAllOpts := &tsapi.ProxyClass{
+		Spec: tsapi.ProxyClassSpec{
+			StatefulSet: &tsapi.StatefulSet{
+				Labels:      map[string]string{"foo": "bar"},
+				Annotations: map[string]string{"foo.io/bar": "foo"},
+				Pod: &tsapi.Pod{
+					Labels:      map[string]string{"bar": "foo"},
+					Annotations: map[string]string{"bar.io/foo": "foo"},
+					SecurityContext: &corev1.PodSecurityContext{
+						RunAsUser: ptr.To(int64(0)),
+					},
+					ImagePullSecrets: []corev1.LocalObjectReference{{Name: "docker-creds"}},
+					NodeName:         "some-node",
+					NodeSelector:     map[string]string{"beta.kubernetes.io/os": "linux"},
+					Affinity:         &corev1.Affinity{NodeAffinity: &corev1.NodeAffinity{RequiredDuringSchedulingIgnoredDuringExecution: &corev1.NodeSelector{}}},
+					Tolerations:      []corev1.Toleration{{Key: "", Operator: "Exists"}},
+					TailscaleContainer: &tsapi.Container{
+						SecurityContext: &corev1.SecurityContext{
+							Privileged: ptr.To(true),
+						},
+						Resources: corev1.ResourceRequirements{
+							Limits:   corev1.ResourceList{corev1.ResourceCPU: resource.MustParse("1000m"), corev1.ResourceMemory: resource.MustParse("128Mi")},
+							Requests: corev1.ResourceList{corev1.ResourceCPU: resource.MustParse("500m"), corev1.ResourceMemory: resource.MustParse("64Mi")},
+						},
+						Env: []tsapi.Env{{Name: "foo", Value: "bar"}, {Name: "TS_USERSPACE", Value: "true"}, {Name: "bar"}},
+					},
+					TailscaleInitContainer: &tsapi.Container{
+						SecurityContext: &corev1.SecurityContext{
+							Privileged: ptr.To(true),
+							RunAsUser:  ptr.To(int64(0)),
+						},
+						Resources: corev1.ResourceRequirements{
+							Limits:   corev1.ResourceList{corev1.ResourceCPU: resource.MustParse("1000m"), corev1.ResourceMemory: resource.MustParse("128Mi")},
+							Requests: corev1.ResourceList{corev1.ResourceCPU: resource.MustParse("500m"), corev1.ResourceMemory: resource.MustParse("64Mi")},
+						},
+						Env: []tsapi.Env{{Name: "foo", Value: "bar"}, {Name: "TS_USERSPACE", Value: "true"}, {Name: "bar"}},
+					},
+				},
+			},
+		},
+	}
+	proxyClassJustLabels := &tsapi.ProxyClass{
+		Spec: tsapi.ProxyClassSpec{
+			StatefulSet: &tsapi.StatefulSet{
+				Labels:      map[string]string{"foo": "bar"},
+				Annotations: map[string]string{"foo.io/bar": "foo"},
+				Pod: &tsapi.Pod{
+					Labels:      map[string]string{"bar": "foo"},
+					Annotations: map[string]string{"bar.io/foo": "foo"},
+				},
+			},
+		},
+	}
+	proxyClassMetrics := &tsapi.ProxyClass{
+		Spec: tsapi.ProxyClassSpec{
+			Metrics: &tsapi.Metrics{Enable: true},
+		},
+	}
+
+	var userspaceProxySS, nonUserspaceProxySS appsv1.StatefulSet
+	if err := yaml.Unmarshal(userspaceProxyYaml, &userspaceProxySS); err != nil {
+		t.Fatalf("unmarshaling userspace proxy template: %v", err)
+	}
+	if err := yaml.Unmarshal(proxyYaml, &nonUserspaceProxySS); err != nil {
+		t.Fatalf("unmarshaling non-userspace proxy template: %v", err)
+	}
+	// Set a couple additional fields so we can test that we don't
+	// mistakenly override those.
+	labels := map[string]string{
+		LabelManaged:    "true",
+		LabelParentName: "foo",
+	}
+	annots := map[string]string{
+		podAnnotationLastSetClusterIP: "1.2.3.4",
+	}
+	env := []corev1.EnvVar{{Name: "TS_HOSTNAME", Value: "nginx"}}
+	userspaceProxySS.Labels = labels
+	userspaceProxySS.Annotations = annots
+	userspaceProxySS.Spec.Template.Spec.Containers[0].Env = env
+	nonUserspaceProxySS.ObjectMeta.Labels = labels
+	nonUserspaceProxySS.ObjectMeta.Annotations = annots
+	nonUserspaceProxySS.Spec.Template.Spec.Containers[0].Env = env
+
+	// 1. Test that a ProxyClass with all fields set gets correctly applied
+	// to a Statefulset built from non-userspace proxy template.
+	wantSS := nonUserspaceProxySS.DeepCopy()
+	wantSS.ObjectMeta.Labels = mergeMapKeys(wantSS.ObjectMeta.Labels, proxyClassAllOpts.Spec.StatefulSet.Labels)
+	wantSS.ObjectMeta.Annotations = mergeMapKeys(wantSS.ObjectMeta.Annotations, proxyClassAllOpts.Spec.StatefulSet.Annotations)
+	wantSS.Spec.Template.Labels = proxyClassAllOpts.Spec.StatefulSet.Pod.Labels
+	wantSS.Spec.Template.Annotations = proxyClassAllOpts.Spec.StatefulSet.Pod.Annotations
+	wantSS.Spec.Template.Spec.SecurityContext = proxyClassAllOpts.Spec.StatefulSet.Pod.SecurityContext
+	wantSS.Spec.Template.Spec.ImagePullSecrets = proxyClassAllOpts.Spec.StatefulSet.Pod.ImagePullSecrets
+	wantSS.Spec.Template.Spec.NodeName = proxyClassAllOpts.Spec.StatefulSet.Pod.NodeName
+	wantSS.Spec.Template.Spec.NodeSelector = proxyClassAllOpts.Spec.StatefulSet.Pod.NodeSelector
+	wantSS.Spec.Template.Spec.Affinity = proxyClassAllOpts.Spec.StatefulSet.Pod.Affinity
+	wantSS.Spec.Template.Spec.Tolerations = proxyClassAllOpts.Spec.StatefulSet.Pod.Tolerations
+	wantSS.Spec.Template.Spec.Containers[0].SecurityContext = proxyClassAllOpts.Spec.StatefulSet.Pod.TailscaleContainer.SecurityContext
+	wantSS.Spec.Template.Spec.InitContainers[0].SecurityContext = proxyClassAllOpts.Spec.StatefulSet.Pod.TailscaleInitContainer.SecurityContext
+	wantSS.Spec.Template.Spec.Containers[0].Resources = proxyClassAllOpts.Spec.StatefulSet.Pod.TailscaleContainer.Resources
+	wantSS.Spec.Template.Spec.InitContainers[0].Resources = proxyClassAllOpts.Spec.StatefulSet.Pod.TailscaleInitContainer.Resources
+	wantSS.Spec.Template.Spec.InitContainers[0].Env = append(wantSS.Spec.Template.Spec.InitContainers[0].Env, []corev1.EnvVar{{Name: "foo", Value: "bar"}, {Name: "TS_USERSPACE", Value: "true"}, {Name: "bar"}}...)
+	wantSS.Spec.Template.Spec.Containers[0].Env = append(wantSS.Spec.Template.Spec.Containers[0].Env, []corev1.EnvVar{{Name: "foo", Value: "bar"}, {Name: "TS_USERSPACE", Value: "true"}, {Name: "bar"}}...)
+
+	gotSS := applyProxyClassToStatefulSet(proxyClassAllOpts, nonUserspaceProxySS.DeepCopy(), new(tailscaleSTSConfig), zl.Sugar())
+	if diff := cmp.Diff(gotSS, wantSS); diff != "" {
+		t.Fatalf("Unexpected result applying ProxyClass with all fields set to a StatefulSet for non-userspace proxy (-got +want):\n%s", diff)
+	}
+
+	// 2. Test that a ProxyClass with custom labels and annotations for
+	// StatefulSet and Pod set gets correctly applied to a Statefulset built
+	// from non-userspace proxy template.
+	wantSS = nonUserspaceProxySS.DeepCopy()
+	wantSS.ObjectMeta.Labels = mergeMapKeys(wantSS.ObjectMeta.Labels, proxyClassJustLabels.Spec.StatefulSet.Labels)
+	wantSS.ObjectMeta.Annotations = mergeMapKeys(wantSS.ObjectMeta.Annotations, proxyClassJustLabels.Spec.StatefulSet.Annotations)
+	wantSS.Spec.Template.Labels = proxyClassJustLabels.Spec.StatefulSet.Pod.Labels
+	wantSS.Spec.Template.Annotations = proxyClassJustLabels.Spec.StatefulSet.Pod.Annotations
+	gotSS = applyProxyClassToStatefulSet(proxyClassJustLabels, nonUserspaceProxySS.DeepCopy(), new(tailscaleSTSConfig), zl.Sugar())
+	if diff := cmp.Diff(gotSS, wantSS); diff != "" {
+		t.Fatalf("Unexpected result applying ProxyClass with custom labels and annotations to a StatefulSet for non-userspace proxy (-got +want):\n%s", diff)
+	}
+
+	// 3. Test that a ProxyClass with all fields set gets correctly applied
+	// to a Statefulset built from a userspace proxy template.
+	wantSS = userspaceProxySS.DeepCopy()
+	wantSS.ObjectMeta.Labels = mergeMapKeys(wantSS.ObjectMeta.Labels, proxyClassAllOpts.Spec.StatefulSet.Labels)
+	wantSS.ObjectMeta.Annotations = mergeMapKeys(wantSS.ObjectMeta.Annotations, proxyClassAllOpts.Spec.StatefulSet.Annotations)
+	wantSS.Spec.Template.Labels = proxyClassAllOpts.Spec.StatefulSet.Pod.Labels
+	wantSS.Spec.Template.Annotations = proxyClassAllOpts.Spec.StatefulSet.Pod.Annotations
+	wantSS.Spec.Template.Spec.SecurityContext = proxyClassAllOpts.Spec.StatefulSet.Pod.SecurityContext
+	wantSS.Spec.Template.Spec.ImagePullSecrets = proxyClassAllOpts.Spec.StatefulSet.Pod.ImagePullSecrets
+	wantSS.Spec.Template.Spec.NodeName = proxyClassAllOpts.Spec.StatefulSet.Pod.NodeName
+	wantSS.Spec.Template.Spec.NodeSelector = proxyClassAllOpts.Spec.StatefulSet.Pod.NodeSelector
+	wantSS.Spec.Template.Spec.Affinity = proxyClassAllOpts.Spec.StatefulSet.Pod.Affinity
+	wantSS.Spec.Template.Spec.Tolerations = proxyClassAllOpts.Spec.StatefulSet.Pod.Tolerations
+	wantSS.Spec.Template.Spec.Containers[0].SecurityContext = proxyClassAllOpts.Spec.StatefulSet.Pod.TailscaleContainer.SecurityContext
+	wantSS.Spec.Template.Spec.Containers[0].Resources = proxyClassAllOpts.Spec.StatefulSet.Pod.TailscaleContainer.Resources
+	wantSS.Spec.Template.Spec.Containers[0].Env = append(wantSS.Spec.Template.Spec.Containers[0].Env, []corev1.EnvVar{{Name: "foo", Value: "bar"}, {Name: "TS_USERSPACE", Value: "true"}, {Name: "bar"}}...)
+	gotSS = applyProxyClassToStatefulSet(proxyClassAllOpts, userspaceProxySS.DeepCopy(), new(tailscaleSTSConfig), zl.Sugar())
+	if diff := cmp.Diff(gotSS, wantSS); diff != "" {
+		t.Fatalf("Unexpected result applying ProxyClass with custom labels and annotations to a StatefulSet for a userspace proxy (-got +want):\n%s", diff)
+	}
+
+	// 4. Test that a ProxyClass with custom labels and annotations gets correctly applied
+	// to a Statefulset built from a userspace proxy template.
+	wantSS = userspaceProxySS.DeepCopy()
+	wantSS.ObjectMeta.Labels = mergeMapKeys(wantSS.ObjectMeta.Labels, proxyClassJustLabels.Spec.StatefulSet.Labels)
+	wantSS.ObjectMeta.Annotations = mergeMapKeys(wantSS.ObjectMeta.Annotations, proxyClassJustLabels.Spec.StatefulSet.Annotations)
+	wantSS.Spec.Template.Labels = proxyClassJustLabels.Spec.StatefulSet.Pod.Labels
+	wantSS.Spec.Template.Annotations = proxyClassJustLabels.Spec.StatefulSet.Pod.Annotations
+	gotSS = applyProxyClassToStatefulSet(proxyClassJustLabels, userspaceProxySS.DeepCopy(), new(tailscaleSTSConfig), zl.Sugar())
+	if diff := cmp.Diff(gotSS, wantSS); diff != "" {
+		t.Fatalf("Unexpected result applying ProxyClass with custom labels and annotations to a StatefulSet for a userspace proxy (-got +want):\n%s", diff)
+	}
+
+	// 5. Test that a ProxyClass with metrics enabled gets correctly applied to a StatefulSet.
+	wantSS = nonUserspaceProxySS.DeepCopy()
+	wantSS.Spec.Template.Spec.Containers[0].Env = append(wantSS.Spec.Template.Spec.Containers[0].Env, corev1.EnvVar{Name: "TS_TAILSCALED_EXTRA_ARGS", Value: "--debug=$(POD_IP):9001"})
+	wantSS.Spec.Template.Spec.Containers[0].Ports = []corev1.ContainerPort{{Name: "metrics", Protocol: "TCP", ContainerPort: 9001, HostPort: 9001}}
+	gotSS = applyProxyClassToStatefulSet(proxyClassMetrics, nonUserspaceProxySS.DeepCopy(), new(tailscaleSTSConfig), zl.Sugar())
+	if diff := cmp.Diff(gotSS, wantSS); diff != "" {
+		t.Fatalf("Unexpected result applying ProxyClass with metrics enabled to a StatefulSet (-got +want):\n%s", diff)
+	}
+}
+
+func mergeMapKeys(a, b map[string]string) map[string]string {
+	for key, val := range b {
+		a[key] = val
+	}
+	return a
+}
+
+func Test_mergeStatefulSetLabelsOrAnnots(t *testing.T) {
+	tests := []struct {
+		name    string
+		current map[string]string
+		custom  map[string]string
+		managed []string
+		want    map[string]string
+	}{
+		{
+			name:    "no custom labels specified and none present in current labels, return current labels",
+			current: map[string]string{LabelManaged: "true", LabelParentName: "foo", LabelParentType: "svc", LabelParentNamespace: "foo"},
+			want:    map[string]string{LabelManaged: "true", LabelParentName: "foo", LabelParentType: "svc", LabelParentNamespace: "foo"},
+			managed: tailscaleManagedLabels,
+		},
+		{
+			name:    "no custom labels specified, but some present in current labels, return tailscale managed labels only from the current labels",
+			current: map[string]string{"foo": "bar", "something.io/foo": "bar", LabelManaged: "true", LabelParentName: "foo", LabelParentType: "svc", LabelParentNamespace: "foo"},
+			want:    map[string]string{LabelManaged: "true", LabelParentName: "foo", LabelParentType: "svc", LabelParentNamespace: "foo"},
+			managed: tailscaleManagedLabels,
+		},
+		{
+			name:    "custom labels specified, current labels only contain tailscale managed labels, return a union of both",
+			current: map[string]string{LabelManaged: "true", LabelParentName: "foo", LabelParentType: "svc", LabelParentNamespace: "foo"},
+			custom:  map[string]string{"foo": "bar", "something.io/foo": "bar"},
+			want:    map[string]string{"foo": "bar", "something.io/foo": "bar", LabelManaged: "true", LabelParentName: "foo", LabelParentType: "svc", LabelParentNamespace: "foo"},
+			managed: tailscaleManagedLabels,
+		},
+		{
+			name:    "custom labels specified, current labels contain tailscale managed labels and custom labels, some of which re not present in the new custom labels, return a union of managed labels and the desired custom labels",
+			current: map[string]string{"foo": "bar", "bar": "baz", "app": "1234", LabelManaged: "true", LabelParentName: "foo", LabelParentType: "svc", LabelParentNamespace: "foo"},
+			custom:  map[string]string{"foo": "bar", "something.io/foo": "bar"},
+			want:    map[string]string{"foo": "bar", "something.io/foo": "bar", "app": "1234", LabelManaged: "true", LabelParentName: "foo", LabelParentType: "svc", LabelParentNamespace: "foo"},
+			managed: tailscaleManagedLabels,
+		},
+		{
+			name:    "no current labels present, return custom labels only",
+			custom:  map[string]string{"foo": "bar", "something.io/foo": "bar"},
+			want:    map[string]string{"foo": "bar", "something.io/foo": "bar"},
+			managed: tailscaleManagedLabels,
+		},
+		{
+			name:    "no current labels present, no custom labels specified, return empty map",
+			want:    map[string]string{},
+			managed: tailscaleManagedLabels,
+		},
+		{
+			name:    "no custom annots specified and none present in current annots, return current annots",
+			current: map[string]string{podAnnotationLastSetClusterIP: "1.2.3.4"},
+			want:    map[string]string{podAnnotationLastSetClusterIP: "1.2.3.4"},
+			managed: tailscaleManagedAnnotations,
+		},
+		{
+			name:    "no custom annots specified, but some present in current annots, return tailscale managed annots only from the current annots",
+			current: map[string]string{"foo": "bar", "something.io/foo": "bar", podAnnotationLastSetClusterIP: "1.2.3.4"},
+			want:    map[string]string{podAnnotationLastSetClusterIP: "1.2.3.4"},
+			managed: tailscaleManagedAnnotations,
+		},
+		{
+			name:    "custom annots specified, current annots only contain tailscale managed annots, return a union of both",
+			current: map[string]string{podAnnotationLastSetClusterIP: "1.2.3.4"},
+			custom:  map[string]string{"foo": "bar", "something.io/foo": "bar"},
+			want:    map[string]string{"foo": "bar", "something.io/foo": "bar", podAnnotationLastSetClusterIP: "1.2.3.4"},
+			managed: tailscaleManagedAnnotations,
+		},
+		{
+			name:    "custom annots specified, current annots contain tailscale managed annots and custom annots, some of which are not present in the new custom annots, return a union of managed annots and the desired custom annots",
+			current: map[string]string{"foo": "bar", "something.io/foo": "bar", podAnnotationLastSetClusterIP: "1.2.3.4"},
+			custom:  map[string]string{"something.io/foo": "bar"},
+			want:    map[string]string{"something.io/foo": "bar", podAnnotationLastSetClusterIP: "1.2.3.4"},
+			managed: tailscaleManagedAnnotations,
+		},
+		{
+			name:    "no current annots present, return custom annots only",
+			custom:  map[string]string{"foo": "bar", "something.io/foo": "bar"},
+			want:    map[string]string{"foo": "bar", "something.io/foo": "bar"},
+			managed: tailscaleManagedAnnotations,
+		},
+		{
+			name:    "no current labels present, no custom labels specified, return empty map",
+			want:    map[string]string{},
+			managed: tailscaleManagedAnnotations,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := mergeStatefulSetLabelsOrAnnots(tt.current, tt.custom, tt.managed); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("mergeStatefulSetLabels() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}