tailscale/hostinfo/hostinfo.go
Brad Fitzpatrick 45a3de14a6 cmd/tailscaled, tailcfg, hostinfo: add flag to disable logging + support
As noted in #5617, our documented method of blocking log.tailscale.io
DNS no longer works due to bootstrap DNS.

Instead, provide an explicit flag (--no-logs-no-support) and/or env
variable (TS_NO_LOGS_NO_SUPPORT=true) to explicitly disable logcatcher
uploads. It also sets a bit on Hostinfo to say that the node is in that
mode so we can end any support tickets from such nodes more quickly.

This does not yet provide an easy mechanism for users on some
platforms (such as Windows, macOS, Synology) to set flags/env. On
Linux you'd used /etc/default/tailscaled typically. Making it easier
to set flags for other platforms is tracked in #5114.

Fixes #5617
Fixes tailscale/corp#1475

Change-Id: I72404e1789f9e56ec47f9b7021b44c025f7a373a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-09-13 11:47:36 -07:00

376 lines
8.4 KiB
Go

// 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"
"runtime"
"strings"
"sync"
"sync/atomic"
"time"
"go4.org/mem"
"tailscale.com/envknob"
"tailscale.com/tailcfg"
"tailscale.com/types/opt"
"tailscale.com/util/cloudenv"
"tailscale.com/util/dnsname"
"tailscale.com/util/lineread"
"tailscale.com/version"
)
var started = time.Now()
// 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(),
Container: lazyInContainer.Get(),
Distro: condCall(distroName),
DistroVersion: condCall(distroVersion),
DistroCodeName: condCall(distroCodeName),
Env: string(GetEnvType()),
Desktop: desktop(),
Package: packageTypeCached(),
GoArch: runtime.GOARCH,
GoVersion: runtime.Version(),
DeviceModel: deviceModel(),
Cloud: string(cloudenv.Get()),
NoLogsNoSupport: envknob.NoLogsNoSupport(),
}
}
// non-nil on some platforms
var (
osVersion func() string
packageType func() string
distroName func() string
distroVersion func() string
distroCodeName func() string
)
func condCall[T any](fn func() T) T {
var zero T
if fn == nil {
return zero
}
return fn()
}
var (
lazyInContainer = &lazyAtomicValue[opt.Bool]{f: ptrTo(inContainer)}
)
func ptrTo[T any](v T) *T { return &v }
type lazyAtomicValue[T any] struct {
// f is a pointer to a fill function. If it's nil or points
// to nil, then Get returns the zero value for T.
f *func() T
once sync.Once
v T
}
func (v *lazyAtomicValue[T]) Get() T {
v.once.Do(v.fill)
return v.v
}
func (v *lazyAtomicValue[T]) fill() {
if v.f == nil || *v.f == nil {
return
}
v.v = (*v.f)()
}
// 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 packageTypeCached() string {
if v, _ := packagingType.Load().(string); v != "" {
return v
}
if packageType == nil {
return ""
}
v := packageType()
if v != "" {
SetPackage(v)
}
return v
}
// 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")
DockerDesktop = EnvType("dde")
)
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
desktopAtomic atomic.Value // of opt.Bool
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.
//
// As of 2022-03-25, this is used by Android ("nogoogle" for the
// F-Droid build) and tsnet (set to "tsnet").
func SetPackage(v string) { packagingType.Store(v) }
func deviceModel() string {
s, _ := deviceModelAtomic.Load().(string)
return s
}
func desktop() (ret opt.Bool) {
if runtime.GOOS != "linux" {
return opt.Bool("")
}
if v := desktopAtomic.Load(); v != nil {
v, _ := v.(opt.Bool)
return v
}
seenDesktop := false
lineread.File("/proc/net/unix", func(line []byte) error {
seenDesktop = seenDesktop || mem.Contains(mem.B(line), mem.S(" @/tmp/dbus-"))
seenDesktop = seenDesktop || mem.Contains(mem.B(line), mem.S(".X11-unix"))
seenDesktop = seenDesktop || mem.Contains(mem.B(line), mem.S("/wayland-1"))
return nil
})
ret.Set(seenDesktop)
// Only cache after a minute - compositors might not have started yet.
if time.Since(started) > time.Minute {
desktopAtomic.Store(ret)
}
return ret
}
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
}
if inDockerDesktop() {
return DockerDesktop
}
return ""
}
// inContainer reports whether we're running in a container.
func inContainer() opt.Bool {
if runtime.GOOS != "linux" {
return ""
}
var ret opt.Bool
ret.Set(false)
if _, err := os.Stat("/.dockerenv"); err == nil {
ret.Set(true)
return ret
}
if _, err := os.Stat("/run/.containerenv"); err == nil {
// See https://github.com/cri-o/cri-o/issues/5461
ret.Set(true)
return ret
}
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.Set(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.Set(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
}
func inDockerDesktop() bool {
if os.Getenv("TS_HOST_ENV") == "dde" {
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
}