tailscale/cmd/containerboot/settings.go

325 lines
13 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
//go:build linux
package main
import (
"context"
"errors"
"fmt"
"log"
"net/netip"
"os"
"path"
"strconv"
"strings"
"tailscale.com/ipn/conffile"
"tailscale.com/kube/kubeclient"
)
// settings is all the configuration for containerboot.
type settings struct {
AuthKey string
Hostname string
Routes *string
// 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.
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.
TailnetTargetIP string
// TailnetTargetFQDN is an MagicDNS name to which all incoming
// non-Tailscale traffic should be proxied. This must be a full Tailnet
// node FQDN.
TailnetTargetFQDN string
ServeConfigPath string
DaemonExtraArgs string
ExtraArgs string
InKubernetes bool
UserspaceMode bool
StateDir string
AcceptDNS *bool
KubeSecret string
SOCKSProxyAddr string
HTTPProxyAddr string
Socket string
AuthOnce bool
Root string
KubernetesCanPatch bool
TailscaledConfigFilePath string
EnableForwardingOptimizations bool
// 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.
// Deprecated: use PodIPv4, PodIPv6 instead to support dual stack clusters
PodIP string
PodIPv4 string
PodIPv6 string
HealthCheckAddrPort string
EgressSvcsCfgPath string
}
func configFromEnv() (*settings, error) {
cfg := &settings{
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", ""),
EnableForwardingOptimizations: defaultBool("TS_EXPERIMENTAL_ENABLE_FORWARDING_OPTIMIZATIONS", false),
HealthCheckAddrPort: defaultEnv("TS_HEALTHCHECK_ADDR_PORT", ""),
EgressSvcsCfgPath: defaultEnv("TS_EGRESS_SERVICES_CONFIG_PATH", ""),
}
podIPs, ok := os.LookupEnv("POD_IPS")
if ok {
ips := strings.Split(podIPs, ",")
if len(ips) > 2 {
return nil, fmt.Errorf("POD_IPs can contain at most 2 IPs, got %d (%v)", len(ips), ips)
}
for _, ip := range ips {
parsed, err := netip.ParseAddr(ip)
if err != nil {
return nil, fmt.Errorf("error parsing IP address %s: %w", ip, err)
}
if parsed.Is4() {
cfg.PodIPv4 = parsed.String()
continue
}
cfg.PodIPv6 = parsed.String()
}
}
if err := cfg.validate(); err != nil {
return nil, fmt.Errorf("invalid configuration: %v", err)
}
return cfg, nil
}
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.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")
}
if s.TailnetTargetFQDN != "" && s.UserspaceMode {
return errors.New("TS_TAILNET_TARGET_FQDN is not supported with TS_USERSPACE")
}
if s.TailnetTargetFQDN != "" && s.TailnetTargetIP != "" {
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("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")
}
if s.EnableForwardingOptimizations && s.UserspaceMode {
return errors.New("TS_EXPERIMENTAL_ENABLE_FORWARDING_OPTIMIZATIONS is not supported in userspace mode")
}
if s.HealthCheckAddrPort != "" {
if _, err := netip.ParseAddrPort(s.HealthCheckAddrPort); err != nil {
return fmt.Errorf("error parsing TS_HEALTH_CHECK_ADDR_PORT value %q: %w", s.HealthCheckAddrPort, err)
}
}
return nil
}
// 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 {
if !kubeclient.IsNotFoundErr(err) {
return fmt.Errorf("getting Tailscale state Secret %s: %v", cfg.KubeSecret, err)
}
if !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)
}
}
// Return early if we already have an auth key.
if cfg.AuthKey != "" || isOneStepConfig(cfg) {
return nil
}
if s == nil {
log.Print("TS_AUTHKEY not provided and state Secret does not exist, login will be interactive if needed.")
return nil
}
keyBytes, _ := s.Data["authkey"]
key := string(keyBytes)
if key != "" {
// 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
}
log.Print("No authkey found in state Secret and TS_AUTHKEY not provided, login will be interactive if needed.")
return nil
}
// isTwoStepConfigAuthOnce returns true if the Tailscale node should be configured
// in two steps and login should only happen once.
// Step 1: run 'tailscaled'
// Step 2):
// A) if this is the first time starting this node run 'tailscale up --authkey <authkey> <config opts>'
// B) if this is not the first time starting this node run 'tailscale set <config opts>'.
func isTwoStepConfigAuthOnce(cfg *settings) bool {
return cfg.AuthOnce && cfg.TailscaledConfigFilePath == ""
}
// isTwoStepConfigAlwaysAuth returns true if the Tailscale node should be configured
// in two steps and we should log in every time it starts.
// Step 1: run 'tailscaled'
// Step 2): run 'tailscale up --authkey <authkey> <config opts>'
func isTwoStepConfigAlwaysAuth(cfg *settings) bool {
return !cfg.AuthOnce && cfg.TailscaledConfigFilePath == ""
}
// isOneStepConfig returns true if the Tailscale node should always be ran and
// configured in a single step by running 'tailscaled <config opts>'
func isOneStepConfig(cfg *settings) bool {
return cfg.TailscaledConfigFilePath != ""
}
// isL3Proxy returns true if the Tailscale node needs to be configured to act
// as an L3 proxy, proxying to an endpoint provided via one of the config env
// vars.
func isL3Proxy(cfg *settings) bool {
return cfg.ProxyTargetIP != "" || cfg.ProxyTargetDNSName != "" || cfg.TailnetTargetIP != "" || cfg.TailnetTargetFQDN != "" || cfg.AllowProxyingClusterTrafficViaIngress || cfg.EgressSvcsCfgPath != ""
}
// hasKubeStateStore returns true if the state must be stored in a Kubernetes
// Secret.
func hasKubeStateStore(cfg *settings) bool {
return cfg.InKubernetes && cfg.KubernetesCanPatch && cfg.KubeSecret != ""
}
// defaultEnv returns the value of the given envvar name, or defVal if
// unset.
func defaultEnv(name, defVal string) string {
if v, ok := os.LookupEnv(name); ok {
return v
}
return defVal
}
// defaultEnvStringPointer returns a pointer to the given envvar value if set, else
// returns nil. This is useful in cases where we need to distinguish between a
// variable being set to empty string vs unset.
func defaultEnvStringPointer(name string) *string {
if v, ok := os.LookupEnv(name); ok {
return &v
}
return nil
}
// defaultEnvBoolPointer returns a pointer to the given envvar value if set, else
// returns nil. This is useful in cases where we need to distinguish between a
// variable being explicitly set to false vs unset.
func defaultEnvBoolPointer(name string) *bool {
v := os.Getenv(name)
ret, err := strconv.ParseBool(v)
if err != nil {
return nil
}
return &ret
}
func defaultEnvs(names []string, defVal string) string {
for _, name := range names {
if v, ok := os.LookupEnv(name); ok {
return v
}
}
return defVal
}
// defaultBool returns the boolean value of the given envvar name, or
// defVal if unset or not a bool.
func defaultBool(name string, defVal bool) bool {
v := os.Getenv(name)
ret, err := strconv.ParseBool(v)
if err != nil {
return defVal
}
return ret
}