envknob, hostinfo, ipn/ipnlocal: add start of opt-in remote update support

Updates #6907

Change-Id: I85db4f6f831dd5ff7a9ef4bfa25902607e0c1558
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
pull/7040/head
Brad Fitzpatrick 2 years ago committed by Brad Fitzpatrick
parent b74db24149
commit b6aa1c1f22

@ -329,6 +329,13 @@ func NoLogsNoSupport() bool {
return Bool("TS_NO_LOGS_NO_SUPPORT")
}
var allowRemoteUpdate = RegisterBool("TS_ALLOW_ADMIN_CONSOLE_REMOTE_UPDATE")
// AllowsRemoteUpdate reports whether this node has opted-in to letting the
// Tailscale control plane initiate a Tailscale update (e.g. on behalf of an
// admin on the admin console).
func AllowsRemoteUpdate() bool { return allowRemoteUpdate() }
// SetNoLogsNoSupport enables no-logs-no-support mode.
func SetNoLogsNoSupport() {
Setenv("TS_NO_LOGS_NO_SUPPORT", "true")

@ -53,6 +53,7 @@ func New() *tailcfg.Hostinfo {
DeviceModel: deviceModel(),
Cloud: string(cloudenv.Get()),
NoLogsNoSupport: envknob.NoLogsNoSupport(),
AllowsUpdate: envknob.AllowsRemoteUpdate(),
}
}

@ -6,14 +6,23 @@ package ipnlocal
import (
"encoding/json"
"errors"
"fmt"
"io"
"net/http"
"os"
"os/exec"
"path/filepath"
"runtime"
"strconv"
"time"
"tailscale.com/envknob"
"tailscale.com/tailcfg"
"tailscale.com/util/clientmetric"
"tailscale.com/util/goroutines"
"tailscale.com/version"
"tailscale.com/version/distro"
)
func (b *LocalBackend) handleC2N(w http.ResponseWriter, r *http.Request) {
@ -26,6 +35,8 @@ func (b *LocalBackend) handleC2N(w http.ResponseWriter, r *http.Request) {
// Test handler.
body, _ := io.ReadAll(r.Body)
w.Write(body)
case "/update":
b.handleC2NUpdate(w, r)
case "/logtail/flush":
if r.Method != "POST" {
http.Error(w, "bad method", http.StatusMethodNotAllowed)
@ -77,3 +88,108 @@ func (b *LocalBackend) handleC2N(w http.ResponseWriter, r *http.Request) {
http.Error(w, "unknown c2n path", http.StatusBadRequest)
}
}
func (b *LocalBackend) handleC2NUpdate(w http.ResponseWriter, r *http.Request) {
// TODO(bradfitz): add some sort of semaphore that prevents two concurrent
// updates, or if one happened in the past 5 minutes, or something.
// TODO(bradfitz): move this type to some leaf package
type updateResponse struct {
Err string // error message, if any
Enabled bool // user has opted-in to remote updates
Supported bool // Tailscale supports updating this OS/platform
Started bool
}
var res updateResponse
res.Enabled = envknob.AllowsRemoteUpdate()
res.Supported = runtime.GOOS == "windows" || (runtime.GOOS == "linux" && distro.Get() == distro.Debian)
switch r.Method {
case "GET", "POST":
default:
http.Error(w, "bad method", http.StatusMethodNotAllowed)
return
}
defer func() {
w.Header().Set("Content-Type", "application/json")
json.NewEncoder(w).Encode(res)
}()
if r.Method == "GET" {
return
}
if !res.Enabled {
res.Err = "not enabled"
return
}
if !res.Supported {
res.Err = "not supported"
return
}
cmdTS, err := findCmdTailscale()
if err != nil {
res.Err = fmt.Sprintf("failed to find cmd/tailscale binary: %v", err)
return
}
var ver struct {
Long string `json:"long"`
}
out, err := exec.Command(cmdTS, "version", "--json").Output()
if err != nil {
res.Err = fmt.Sprintf("failed to find cmd/tailscale binary: %v", err)
return
}
if err := json.Unmarshal(out, &ver); err != nil {
res.Err = "invalid JSON from cmd/tailscale version --json"
return
}
if ver.Long != version.Long {
res.Err = "cmd/tailscale version mismatch"
return
}
cmd := exec.Command(cmdTS, "update", "--yes")
if err := cmd.Start(); err != nil {
res.Err = fmt.Sprintf("failed to start cmd/tailscale update: %v", err)
return
}
res.Started = true
// TODO(bradfitz,andrew): There might be a race condition here on Windows:
// * We start the update process.
// * tailscale.exe copies itself and kicks off the update process
// * msiexec stops this process during the update before the selfCopy exits(?)
// * This doesn't return because the process is dead.
//
// This seems fairly unlikely, but worth checking.
defer cmd.Wait()
return
}
// findCmdTailscale looks for the cmd/tailscale that corresponds to the
// currently running cmd/tailscaled. It's up to the caller to verify that the
// two match, but this function does its best to find the right one. Notably, it
// doesn't use $PATH for security reasons.
func findCmdTailscale() (string, error) {
self, err := os.Executable()
if err != nil {
return "", err
}
switch runtime.GOOS {
case "linux":
if self == "/usr/sbin/tailscaled" {
return "/usr/bin/tailscale", nil
}
return "", errors.New("tailscale not found in expected place")
case "windows":
dir := filepath.Dir(self)
ts := filepath.Join(dir, "tailscale.exe")
if fi, err := os.Stat(ts); err == nil && fi.Mode().IsRegular() {
return ts, nil
}
return "", errors.New("tailscale.exe not found in expected place")
}
return "", fmt.Errorf("unsupported OS %v", runtime.GOOS)
}

@ -92,7 +92,8 @@ type CapabilityVersion int
// - 52: 2023-01-05: client can handle c2n POST /logtail/flush
// - 53: 2023-01-18: client respects explicit Node.Expired + auto-sets based on Node.KeyExpiry
// - 54: 2023-01-19: Node.Cap added, PeersChangedPatch.Cap, uses Node.Cap for ExitDNS before Hostinfo.Services fallback
const CurrentCapabilityVersion CapabilityVersion = 54
// - 55: 2023-01-23: start of c2n GET+POST /update handler
const CurrentCapabilityVersion CapabilityVersion = 55
type StableID string
@ -528,6 +529,7 @@ type Hostinfo struct {
ShareeNode bool `json:",omitempty"` // indicates this node exists in netmap because it's owned by a shared-to user
NoLogsNoSupport bool `json:",omitempty"` // indicates that the user has opted out of sending logs and support
WireIngress bool `json:",omitempty"` // indicates that the node wants the option to receive ingress connections
AllowsUpdate bool `json:",omitempty"` // indicates that the node has opted-in to admin-console-drive remote updates
Machine string `json:",omitempty"` // the current host's machine type (uname -m)
GoArch string `json:",omitempty"` // GOARCH value (of the built binary)
GoArchVar string `json:",omitempty"` // GOARM, GOAMD64, etc (of the built binary)

@ -137,6 +137,7 @@ var _HostinfoCloneNeedsRegeneration = Hostinfo(struct {
ShareeNode bool
NoLogsNoSupport bool
WireIngress bool
AllowsUpdate bool
Machine string
GoArch string
GoArchVar string

@ -50,6 +50,7 @@ func TestHostinfoEqual(t *testing.T) {
"ShareeNode",
"NoLogsNoSupport",
"WireIngress",
"AllowsUpdate",
"Machine",
"GoArch",
"GoArchVar",

@ -276,6 +276,7 @@ func (v HostinfoView) ShieldsUp() bool { return v.ж.ShieldsUp }
func (v HostinfoView) ShareeNode() bool { return v.ж.ShareeNode }
func (v HostinfoView) NoLogsNoSupport() bool { return v.ж.NoLogsNoSupport }
func (v HostinfoView) WireIngress() bool { return v.ж.WireIngress }
func (v HostinfoView) AllowsUpdate() bool { return v.ж.AllowsUpdate }
func (v HostinfoView) Machine() string { return v.ж.Machine }
func (v HostinfoView) GoArch() string { return v.ж.GoArch }
func (v HostinfoView) GoArchVar() string { return v.ж.GoArchVar }
@ -312,6 +313,7 @@ var _HostinfoViewNeedsRegeneration = Hostinfo(struct {
ShareeNode bool
NoLogsNoSupport bool
WireIngress bool
AllowsUpdate bool
Machine string
GoArch string
GoArchVar string

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