tailscale/hostinfo/hostinfo.go

282 lines
6.5 KiB
Go
Raw Normal View History

// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package hostinfo answers questions about the host environment that Tailscale is
// running on.
package hostinfo
import (
"bufio"
"io"
"os"
"path/filepath"
"runtime"
"strings"
"sync/atomic"
"time"
"go4.org/mem"
"tailscale.com/tailcfg"
"tailscale.com/util/dnsname"
"tailscale.com/util/lineread"
"tailscale.com/version"
)
// New returns a partially populated Hostinfo for the current host.
func New() *tailcfg.Hostinfo {
hostname, _ := os.Hostname()
hostname = dnsname.FirstLabel(hostname)
return &tailcfg.Hostinfo{
IPNVersion: version.Long,
Hostname: hostname,
OS: version.OS(),
OSVersion: GetOSVersion(),
Package: packageType(),
GoArch: runtime.GOARCH,
DeviceModel: deviceModel(),
}
}
var osVersion func() string // non-nil on some platforms
// GetOSVersion returns the OSVersion of current host if available.
func GetOSVersion() string {
if s, _ := osVersionAtomic.Load().(string); s != "" {
return s
}
if osVersion != nil {
return osVersion()
}
return ""
}
func packageType() string {
if v, _ := packagingType.Load().(string); v != "" {
return v
}
switch runtime.GOOS {
case "windows":
if _, err := os.Stat(`C:\ProgramData\chocolatey\lib\tailscale`); err == nil {
return "choco"
}
case "darwin":
// Using tailscaled or IPNExtension?
exe, _ := os.Executable()
return filepath.Base(exe)
case "linux":
// Report whether this is in a snap.
// See https://snapcraft.io/docs/environment-variables
// We just look at two somewhat arbitrarily.
if os.Getenv("SNAP_NAME") != "" && os.Getenv("SNAP") != "" {
return "snap"
}
}
return ""
}
// EnvType represents a known environment type.
// The empty string, the default, means unknown.
type EnvType string
const (
KNative = EnvType("kn")
AWSLambda = EnvType("lm")
Heroku = EnvType("hr")
AzureAppService = EnvType("az")
AWSFargate = EnvType("fg")
FlyDotIo = EnvType("fly")
Kubernetes = EnvType("k8s")
)
var envType atomic.Value // of EnvType
func GetEnvType() EnvType {
if e, ok := envType.Load().(EnvType); ok {
return e
}
e := getEnvType()
envType.Store(e)
return e
}
var (
deviceModelAtomic atomic.Value // of string
osVersionAtomic atomic.Value // of string
packagingType atomic.Value // of string
)
// SetDeviceModel sets the device model for use in Hostinfo updates.
func SetDeviceModel(model string) { deviceModelAtomic.Store(model) }
// SetOSVersion sets the OS version.
func SetOSVersion(v string) { osVersionAtomic.Store(v) }
// SetPackage sets the packaging type for the app.
// This is currently (2021-10-05) only used by Android,
// set to "nogoogle" for the F-Droid build.
func SetPackage(v string) { packagingType.Store(v) }
func deviceModel() string {
s, _ := deviceModelAtomic.Load().(string)
return s
}
func getEnvType() EnvType {
if inKnative() {
return KNative
}
if inAWSLambda() {
return AWSLambda
}
if inHerokuDyno() {
return Heroku
}
if inAzureAppService() {
return AzureAppService
}
if inAWSFargate() {
return AWSFargate
}
if inFlyDotIo() {
return FlyDotIo
}
if inKubernetes() {
return Kubernetes
}
return ""
}
// inContainer reports whether we're running in a container.
func inContainer() bool {
if runtime.GOOS != "linux" {
return false
}
var ret bool
lineread.File("/proc/1/cgroup", func(line []byte) error {
if mem.Contains(mem.B(line), mem.S("/docker/")) ||
mem.Contains(mem.B(line), mem.S("/lxc/")) {
ret = true
return io.EOF // arbitrary non-nil error to stop loop
}
return nil
})
lineread.File("/proc/mounts", func(line []byte) error {
if mem.Contains(mem.B(line), mem.S("fuse.lxcfs")) {
ret = true
return io.EOF
}
return nil
})
return ret
}
func inKnative() bool {
// https://cloud.google.com/run/docs/reference/container-contract#env-vars
if os.Getenv("K_REVISION") != "" && os.Getenv("K_CONFIGURATION") != "" &&
os.Getenv("K_SERVICE") != "" && os.Getenv("PORT") != "" {
return true
}
return false
}
func inAWSLambda() bool {
// https://docs.aws.amazon.com/lambda/latest/dg/configuration-envvars.html
if os.Getenv("AWS_LAMBDA_FUNCTION_NAME") != "" &&
os.Getenv("AWS_LAMBDA_FUNCTION_VERSION") != "" &&
os.Getenv("AWS_LAMBDA_INITIALIZATION_TYPE") != "" &&
os.Getenv("AWS_LAMBDA_RUNTIME_API") != "" {
return true
}
return false
}
func inHerokuDyno() bool {
// https://devcenter.heroku.com/articles/dynos#local-environment-variables
if os.Getenv("PORT") != "" && os.Getenv("DYNO") != "" {
return true
}
return false
}
func inAzureAppService() bool {
if os.Getenv("APPSVC_RUN_ZIP") != "" && os.Getenv("WEBSITE_STACK") != "" &&
os.Getenv("WEBSITE_AUTH_AUTO_AAD") != "" {
return true
}
return false
}
func inAWSFargate() bool {
if os.Getenv("AWS_EXECUTION_ENV") == "AWS_ECS_FARGATE" {
return true
}
return false
}
func inFlyDotIo() bool {
if os.Getenv("FLY_APP_NAME") != "" && os.Getenv("FLY_REGION") != "" {
return true
}
return false
}
func inKubernetes() bool {
if os.Getenv("KUBERNETES_SERVICE_HOST") != "" && os.Getenv("KUBERNETES_SERVICE_PORT") != "" {
return true
}
return false
}
type etcAptSrcResult struct {
mod time.Time
disabled bool
}
var etcAptSrcCache atomic.Value // of etcAptSrcResult
// DisabledEtcAptSource reports whether Ubuntu (or similar) has disabled
// the /etc/apt/sources.list.d/tailscale.list file contents upon upgrade
// to a new release of the distro.
//
// See https://github.com/tailscale/tailscale/issues/3177
func DisabledEtcAptSource() bool {
if runtime.GOOS != "linux" {
return false
}
const path = "/etc/apt/sources.list.d/tailscale.list"
fi, err := os.Stat(path)
if err != nil || !fi.Mode().IsRegular() {
return false
}
mod := fi.ModTime()
if c, ok := etcAptSrcCache.Load().(etcAptSrcResult); ok && c.mod == mod {
return c.disabled
}
f, err := os.Open(path)
if err != nil {
return false
}
defer f.Close()
v := etcAptSourceFileIsDisabled(f)
etcAptSrcCache.Store(etcAptSrcResult{mod: mod, disabled: v})
return v
}
func etcAptSourceFileIsDisabled(r io.Reader) bool {
bs := bufio.NewScanner(r)
disabled := false // did we find the "disabled on upgrade" comment?
for bs.Scan() {
line := strings.TrimSpace(bs.Text())
if strings.Contains(line, "# disabled on upgrade") {
disabled = true
}
if line == "" || line[0] == '#' {
continue
}
// Well, it has some contents in it at least.
return false
}
return disabled
}