headscale/app.go
2022-06-17 17:42:17 +02:00

867 lines
22 KiB
Go

package headscale
import (
"context"
"crypto/tls"
"errors"
"fmt"
"io"
"net"
"net/http"
"os"
"os/signal"
"sort"
"strings"
"sync"
"syscall"
"time"
"github.com/coreos/go-oidc/v3/oidc"
"github.com/gin-gonic/gin"
grpc_middleware "github.com/grpc-ecosystem/go-grpc-middleware"
"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
v1 "github.com/juanfont/headscale/gen/go/headscale/v1"
"github.com/patrickmn/go-cache"
zerolog "github.com/philip-bui/grpc-zerolog"
"github.com/puzpuzpuz/xsync"
zl "github.com/rs/zerolog"
"github.com/rs/zerolog/log"
ginprometheus "github.com/zsais/go-gin-prometheus"
"golang.org/x/crypto/acme"
"golang.org/x/crypto/acme/autocert"
"golang.org/x/oauth2"
"golang.org/x/sync/errgroup"
"google.golang.org/grpc"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/credentials"
"google.golang.org/grpc/credentials/insecure"
"google.golang.org/grpc/metadata"
"google.golang.org/grpc/peer"
"google.golang.org/grpc/reflection"
"google.golang.org/grpc/status"
"gorm.io/gorm"
"tailscale.com/tailcfg"
"tailscale.com/types/dnstype"
"tailscale.com/types/key"
)
const (
errSTUNAddressNotSet = Error("STUN address not set")
errUnsupportedDatabase = Error("unsupported DB")
errUnsupportedLetsEncryptChallengeType = Error(
"unknown value for Lets Encrypt challenge type",
)
)
const (
AuthPrefix = "Bearer "
Postgres = "postgres"
Sqlite = "sqlite3"
updateInterval = 5000
HTTPReadTimeout = 30 * time.Second
privateKeyFileMode = 0o600
registerCacheExpiration = time.Minute * 15
registerCacheCleanup = time.Minute * 20
DisabledClientAuth = "disabled"
RelaxedClientAuth = "relaxed"
EnforcedClientAuth = "enforced"
)
// Headscale represents the base app of the service.
type Headscale struct {
cfg *Config
db *gorm.DB
dbString string
dbType string
dbDebug bool
privateKey *key.MachinePrivate
DERPMap *tailcfg.DERPMap
DERPServer *DERPServer
aclPolicy *ACLPolicy
aclRules []tailcfg.FilterRule
lastStateChange *xsync.MapOf[time.Time]
oidcProvider *oidc.Provider
oauth2Config *oauth2.Config
registrationCache *cache.Cache
ipAllocationMutex sync.Mutex
}
// Look up the TLS constant relative to user-supplied TLS client
// authentication mode. If an unknown mode is supplied, the default
// value, tls.RequireAnyClientCert, is returned. The returned boolean
// indicates if the supplied mode was valid.
func LookupTLSClientAuthMode(mode string) (tls.ClientAuthType, bool) {
switch mode {
case DisabledClientAuth:
// Client cert is _not_ required.
return tls.NoClientCert, true
case RelaxedClientAuth:
// Client cert required, but _not verified_.
return tls.RequireAnyClientCert, true
case EnforcedClientAuth:
// Client cert is _required and verified_.
return tls.RequireAndVerifyClientCert, true
default:
// Return the default when an unknown value is supplied.
return tls.RequireAnyClientCert, false
}
}
func NewHeadscale(cfg *Config) (*Headscale, error) {
privKey, err := readOrCreatePrivateKey(cfg.PrivateKeyPath)
if err != nil {
return nil, fmt.Errorf("failed to read or create private key: %w", err)
}
var dbString string
switch cfg.DBtype {
case Postgres:
dbString = fmt.Sprintf(
"host=%s port=%d dbname=%s user=%s password=%s sslmode=disable",
cfg.DBhost,
cfg.DBport,
cfg.DBname,
cfg.DBuser,
cfg.DBpass,
)
case Sqlite:
dbString = cfg.DBpath
default:
return nil, errUnsupportedDatabase
}
registrationCache := cache.New(
registerCacheExpiration,
registerCacheCleanup,
)
app := Headscale{
cfg: cfg,
dbType: cfg.DBtype,
dbString: dbString,
privateKey: privKey,
aclRules: tailcfg.FilterAllowAll, // default allowall
registrationCache: registrationCache,
}
err = app.initDB()
if err != nil {
return nil, err
}
if cfg.OIDC.Issuer != "" {
err = app.initOIDC()
if err != nil {
return nil, err
}
}
if app.cfg.DNSConfig != nil && app.cfg.DNSConfig.Proxied { // if MagicDNS
magicDNSDomains := generateMagicDNSRootDomains(app.cfg.IPPrefixes)
// we might have routes already from Split DNS
if app.cfg.DNSConfig.Routes == nil {
app.cfg.DNSConfig.Routes = make(map[string][]*dnstype.Resolver)
}
for _, d := range magicDNSDomains {
app.cfg.DNSConfig.Routes[d.WithoutTrailingDot()] = nil
}
}
if cfg.DERP.ServerEnabled {
embeddedDERPServer, err := app.NewDERPServer()
if err != nil {
return nil, err
}
app.DERPServer = embeddedDERPServer
}
return &app, nil
}
// Redirect to our TLS url.
func (h *Headscale) redirect(w http.ResponseWriter, req *http.Request) {
target := h.cfg.ServerURL + req.URL.RequestURI()
http.Redirect(w, req, target, http.StatusFound)
}
// expireEphemeralNodes deletes ephemeral machine records that have not been
// seen for longer than h.cfg.EphemeralNodeInactivityTimeout.
func (h *Headscale) expireEphemeralNodes(milliSeconds int64) {
ticker := time.NewTicker(time.Duration(milliSeconds) * time.Millisecond)
for range ticker.C {
h.expireEphemeralNodesWorker()
}
}
func (h *Headscale) expireEphemeralNodesWorker() {
namespaces, err := h.ListNamespaces()
if err != nil {
log.Error().Err(err).Msg("Error listing namespaces")
return
}
for _, namespace := range namespaces {
machines, err := h.ListMachinesInNamespace(namespace.Name)
if err != nil {
log.Error().
Err(err).
Str("namespace", namespace.Name).
Msg("Error listing machines in namespace")
return
}
expiredFound := false
for _, machine := range machines {
if machine.AuthKey != nil && machine.LastSeen != nil &&
machine.AuthKey.Ephemeral &&
time.Now().
After(machine.LastSeen.Add(h.cfg.EphemeralNodeInactivityTimeout)) {
expiredFound = true
log.Info().
Str("machine", machine.Hostname).
Msg("Ephemeral client removed from database")
err = h.db.Unscoped().Delete(machine).Error
if err != nil {
log.Error().
Err(err).
Str("machine", machine.Hostname).
Msg("🤮 Cannot delete ephemeral machine from the database")
}
}
}
if expiredFound {
h.setLastStateChangeToNow(namespace.Name)
}
}
}
func (h *Headscale) grpcAuthenticationInterceptor(ctx context.Context,
req interface{},
info *grpc.UnaryServerInfo,
handler grpc.UnaryHandler,
) (interface{}, error) {
// Check if the request is coming from the on-server client.
// This is not secure, but it is to maintain maintainability
// with the "legacy" database-based client
// It is also neede for grpc-gateway to be able to connect to
// the server
client, _ := peer.FromContext(ctx)
log.Trace().
Caller().
Str("client_address", client.Addr.String()).
Msg("Client is trying to authenticate")
meta, ok := metadata.FromIncomingContext(ctx)
if !ok {
log.Error().
Caller().
Str("client_address", client.Addr.String()).
Msg("Retrieving metadata is failed")
return ctx, status.Errorf(
codes.InvalidArgument,
"Retrieving metadata is failed",
)
}
authHeader, ok := meta["authorization"]
if !ok {
log.Error().
Caller().
Str("client_address", client.Addr.String()).
Msg("Authorization token is not supplied")
return ctx, status.Errorf(
codes.Unauthenticated,
"Authorization token is not supplied",
)
}
token := authHeader[0]
if !strings.HasPrefix(token, AuthPrefix) {
log.Error().
Caller().
Str("client_address", client.Addr.String()).
Msg(`missing "Bearer " prefix in "Authorization" header`)
return ctx, status.Error(
codes.Unauthenticated,
`missing "Bearer " prefix in "Authorization" header`,
)
}
valid, err := h.ValidateAPIKey(strings.TrimPrefix(token, AuthPrefix))
if err != nil {
log.Error().
Caller().
Err(err).
Str("client_address", client.Addr.String()).
Msg("failed to validate token")
return ctx, status.Error(codes.Internal, "failed to validate token")
}
if !valid {
log.Info().
Str("client_address", client.Addr.String()).
Msg("invalid token")
return ctx, status.Error(codes.Unauthenticated, "invalid token")
}
return handler(ctx, req)
}
func (h *Headscale) httpAuthenticationMiddleware(ctx *gin.Context) {
log.Trace().
Caller().
Str("client_address", ctx.ClientIP()).
Msg("HTTP authentication invoked")
authHeader := ctx.GetHeader("authorization")
if !strings.HasPrefix(authHeader, AuthPrefix) {
log.Error().
Caller().
Str("client_address", ctx.ClientIP()).
Msg(`missing "Bearer " prefix in "Authorization" header`)
ctx.AbortWithStatus(http.StatusUnauthorized)
return
}
valid, err := h.ValidateAPIKey(strings.TrimPrefix(authHeader, AuthPrefix))
if err != nil {
log.Error().
Caller().
Err(err).
Str("client_address", ctx.ClientIP()).
Msg("failed to validate token")
ctx.AbortWithStatus(http.StatusInternalServerError)
return
}
if !valid {
log.Info().
Str("client_address", ctx.ClientIP()).
Msg("invalid token")
ctx.AbortWithStatus(http.StatusUnauthorized)
return
}
ctx.Next()
}
// ensureUnixSocketIsAbsent will check if the given path for headscales unix socket is clear
// and will remove it if it is not.
func (h *Headscale) ensureUnixSocketIsAbsent() error {
// File does not exist, all fine
if _, err := os.Stat(h.cfg.UnixSocket); errors.Is(err, os.ErrNotExist) {
return nil
}
return os.Remove(h.cfg.UnixSocket)
}
func (h *Headscale) createPrometheusRouter() *gin.Engine {
promRouter := gin.Default()
prometheus := ginprometheus.NewPrometheus("gin")
prometheus.Use(promRouter)
return promRouter
}
func (h *Headscale) createRouter(grpcMux *runtime.ServeMux) *gin.Engine {
router := gin.Default()
router.GET(
"/health",
func(c *gin.Context) { c.JSON(http.StatusOK, gin.H{"healthy": "ok"}) },
)
router.GET("/key", gin.WrapF(h.KeyHandler))
router.GET("/register", gin.WrapF(h.RegisterWebAPI))
router.POST("/machine/:id/map", h.PollNetMapHandler)
router.POST("/machine/:id", h.RegistrationHandler)
router.GET("/oidc/register/:mkey", h.RegisterOIDC)
router.GET("/oidc/callback", gin.WrapF(h.OIDCCallback))
router.GET("/apple", gin.WrapF(h.AppleConfigMessage))
router.GET("/apple/:platform", gin.WrapF(h.ApplePlatformConfig))
router.GET("/windows", gin.WrapF(h.WindowsConfigMessage))
router.GET("/windows/tailscale.reg", gin.WrapF(h.WindowsRegConfig))
router.GET("/swagger", gin.WrapF(SwaggerUI))
router.GET("/swagger/v1/openapiv2.json", gin.WrapF(SwaggerAPIv1))
if h.cfg.DERP.ServerEnabled {
router.Any("/derp", h.DERPHandler)
router.Any("/derp/probe", h.DERPProbeHandler)
router.Any("/bootstrap-dns", h.DERPBootstrapDNSHandler)
}
api := router.Group("/api")
api.Use(h.httpAuthenticationMiddleware)
{
api.Any("/v1/*any", gin.WrapF(grpcMux.ServeHTTP))
}
router.NoRoute(stdoutHandler)
return router
}
// Serve launches a GIN server with the Headscale API.
func (h *Headscale) Serve() error {
var err error
// Fetch an initial DERP Map before we start serving
h.DERPMap = GetDERPMap(h.cfg.DERP)
if h.cfg.DERP.ServerEnabled {
// When embedded DERP is enabled we always need a STUN server
if h.cfg.DERP.STUNAddr == "" {
return errSTUNAddressNotSet
}
h.DERPMap.Regions[h.DERPServer.region.RegionID] = &h.DERPServer.region
go h.ServeSTUN()
}
if h.cfg.DERP.AutoUpdate {
derpMapCancelChannel := make(chan struct{})
defer func() { derpMapCancelChannel <- struct{}{} }()
go h.scheduledDERPMapUpdateWorker(derpMapCancelChannel)
}
go h.expireEphemeralNodes(updateInterval)
if zl.GlobalLevel() == zl.TraceLevel {
zerolog.RespLog = true
} else {
zerolog.RespLog = false
}
// Prepare group for running listeners
errorGroup := new(errgroup.Group)
ctx := context.Background()
ctx, cancel := context.WithCancel(ctx)
defer cancel()
//
//
// Set up LOCAL listeners
//
err = h.ensureUnixSocketIsAbsent()
if err != nil {
return fmt.Errorf("unable to remove old socket file: %w", err)
}
socketListener, err := net.Listen("unix", h.cfg.UnixSocket)
if err != nil {
return fmt.Errorf("failed to set up gRPC socket: %w", err)
}
// Change socket permissions
if err := os.Chmod(h.cfg.UnixSocket, h.cfg.UnixSocketPermission); err != nil {
return fmt.Errorf("failed change permission of gRPC socket: %w", err)
}
grpcGatewayMux := runtime.NewServeMux()
// Make the grpc-gateway connect to grpc over socket
grpcGatewayConn, err := grpc.Dial(
h.cfg.UnixSocket,
[]grpc.DialOption{
grpc.WithTransportCredentials(insecure.NewCredentials()),
grpc.WithContextDialer(GrpcSocketDialer),
}...,
)
if err != nil {
return err
}
// Connect to the gRPC server over localhost to skip
// the authentication.
err = v1.RegisterHeadscaleServiceHandler(ctx, grpcGatewayMux, grpcGatewayConn)
if err != nil {
return err
}
// Start the local gRPC server without TLS and without authentication
grpcSocket := grpc.NewServer(zerolog.UnaryInterceptor())
v1.RegisterHeadscaleServiceServer(grpcSocket, newHeadscaleV1APIServer(h))
reflection.Register(grpcSocket)
errorGroup.Go(func() error { return grpcSocket.Serve(socketListener) })
//
//
// Set up REMOTE listeners
//
tlsConfig, err := h.getTLSSettings()
if err != nil {
log.Error().Err(err).Msg("Failed to set up TLS configuration")
return err
}
//
//
// gRPC setup
//
// We are sadly not able to run gRPC and HTTPS (2.0) on the same
// port because the connection mux does not support matching them
// since they are so similar. There is multiple issues open and we
// can revisit this if changes:
// https://github.com/soheilhy/cmux/issues/68
// https://github.com/soheilhy/cmux/issues/91
if tlsConfig != nil || h.cfg.GRPCAllowInsecure {
log.Info().Msgf("Enabling remote gRPC at %s", h.cfg.GRPCAddr)
grpcOptions := []grpc.ServerOption{
grpc.UnaryInterceptor(
grpc_middleware.ChainUnaryServer(
h.grpcAuthenticationInterceptor,
zerolog.NewUnaryServerInterceptor(),
),
),
}
if tlsConfig != nil {
grpcOptions = append(grpcOptions,
grpc.Creds(credentials.NewTLS(tlsConfig)),
)
} else {
log.Warn().Msg("gRPC is running without security")
}
grpcServer := grpc.NewServer(grpcOptions...)
v1.RegisterHeadscaleServiceServer(grpcServer, newHeadscaleV1APIServer(h))
reflection.Register(grpcServer)
grpcListener, err := net.Listen("tcp", h.cfg.GRPCAddr)
if err != nil {
return fmt.Errorf("failed to bind to TCP address: %w", err)
}
errorGroup.Go(func() error { return grpcServer.Serve(grpcListener) })
log.Info().
Msgf("listening and serving gRPC on: %s", h.cfg.GRPCAddr)
}
//
//
// HTTP setup
//
router := h.createRouter(grpcGatewayMux)
httpServer := &http.Server{
Addr: h.cfg.Addr,
Handler: router,
ReadTimeout: HTTPReadTimeout,
// Go does not handle timeouts in HTTP very well, and there is
// no good way to handle streaming timeouts, therefore we need to
// keep this at unlimited and be careful to clean up connections
// https://blog.cloudflare.com/the-complete-guide-to-golang-net-http-timeouts/#aboutstreaming
WriteTimeout: 0,
}
var httpListener net.Listener
if tlsConfig != nil {
httpServer.TLSConfig = tlsConfig
httpListener, err = tls.Listen("tcp", h.cfg.Addr, tlsConfig)
} else {
httpListener, err = net.Listen("tcp", h.cfg.Addr)
}
if err != nil {
return fmt.Errorf("failed to bind to TCP address: %w", err)
}
errorGroup.Go(func() error { return httpServer.Serve(httpListener) })
log.Info().
Msgf("listening and serving HTTP on: %s", h.cfg.Addr)
promRouter := h.createPrometheusRouter()
promHTTPServer := &http.Server{
Addr: h.cfg.MetricsAddr,
Handler: promRouter,
ReadTimeout: HTTPReadTimeout,
WriteTimeout: 0,
}
var promHTTPListener net.Listener
promHTTPListener, err = net.Listen("tcp", h.cfg.MetricsAddr)
if err != nil {
return fmt.Errorf("failed to bind to TCP address: %w", err)
}
errorGroup.Go(func() error { return promHTTPServer.Serve(promHTTPListener) })
log.Info().
Msgf("listening and serving metrics on: %s", h.cfg.MetricsAddr)
// Handle common process-killing signals so we can gracefully shut down:
sigc := make(chan os.Signal, 1)
signal.Notify(sigc,
syscall.SIGHUP,
syscall.SIGINT,
syscall.SIGTERM,
syscall.SIGQUIT,
syscall.SIGHUP)
go func(c chan os.Signal) {
// Wait for a SIGINT or SIGKILL:
for {
sig := <-c
switch sig {
case syscall.SIGHUP:
log.Info().
Str("signal", sig.String()).
Msg("Received SIGHUP, reloading ACL and Config")
// TODO(kradalby): Reload config on SIGHUP
if h.cfg.ACL.PolicyPath != "" {
aclPath := AbsolutePathFromConfigPath(h.cfg.ACL.PolicyPath)
err := h.LoadACLPolicy(aclPath)
if err != nil {
log.Error().Err(err).Msg("Failed to reload ACL policy")
}
log.Info().
Str("path", aclPath).
Msg("ACL policy successfully reloaded, notifying nodes of change")
h.setLastStateChangeToNow()
}
default:
log.Info().
Str("signal", sig.String()).
Msg("Received signal to stop, shutting down gracefully")
// Gracefully shut down servers
promHTTPServer.Shutdown(ctx)
httpServer.Shutdown(ctx)
grpcSocket.GracefulStop()
// Close network listeners
promHTTPListener.Close()
httpListener.Close()
grpcGatewayConn.Close()
// Stop listening (and unlink the socket if unix type):
socketListener.Close()
// And we're done:
os.Exit(0)
}
}
}(sigc)
return errorGroup.Wait()
}
func (h *Headscale) getTLSSettings() (*tls.Config, error) {
var err error
if h.cfg.TLS.LetsEncrypt.Hostname != "" {
if !strings.HasPrefix(h.cfg.ServerURL, "https://") {
log.Warn().
Msg("Listening with TLS but ServerURL does not start with https://")
}
certManager := autocert.Manager{
Prompt: autocert.AcceptTOS,
HostPolicy: autocert.HostWhitelist(h.cfg.TLS.LetsEncrypt.Hostname),
Cache: autocert.DirCache(h.cfg.TLS.LetsEncrypt.CacheDir),
Client: &acme.Client{
DirectoryURL: h.cfg.ACMEURL,
},
Email: h.cfg.ACMEEmail,
}
switch h.cfg.TLS.LetsEncrypt.ChallengeType {
case "TLS-ALPN-01":
// Configuration via autocert with TLS-ALPN-01 (https://tools.ietf.org/html/rfc8737)
// The RFC requires that the validation is done on port 443; in other words, headscale
// must be reachable on port 443.
return certManager.TLSConfig(), nil
case "HTTP-01":
// Configuration via autocert with HTTP-01. This requires listening on
// port 80 for the certificate validation in addition to the headscale
// service, which can be configured to run on any other port.
go func() {
log.Fatal().
Caller().
Err(http.ListenAndServe(h.cfg.TLS.LetsEncrypt.Listen, certManager.HTTPHandler(http.HandlerFunc(h.redirect)))).
Msg("failed to set up a HTTP server")
}()
return certManager.TLSConfig(), nil
default:
return nil, errUnsupportedLetsEncryptChallengeType
}
} else if h.cfg.TLS.CertPath == "" {
if !strings.HasPrefix(h.cfg.ServerURL, "http://") {
log.Warn().Msg("Listening without TLS but ServerURL does not start with http://")
}
return nil, err
} else {
if !strings.HasPrefix(h.cfg.ServerURL, "https://") {
log.Warn().Msg("Listening with TLS but ServerURL does not start with https://")
}
log.Info().Msg(fmt.Sprintf(
"Client authentication (mTLS) is \"%s\". See the docs to learn about configuring this setting.",
h.cfg.TLS.ClientAuthMode))
tlsConfig := &tls.Config{
ClientAuth: h.cfg.TLS.ClientAuthMode,
NextProtos: []string{"http/1.1"},
Certificates: make([]tls.Certificate, 1),
MinVersion: tls.VersionTLS12,
}
tlsConfig.Certificates[0], err = tls.LoadX509KeyPair(h.cfg.TLS.CertPath, h.cfg.TLS.KeyPath)
return tlsConfig, err
}
}
func (h *Headscale) setLastStateChangeToNow(namespaces ...string) {
var err error
now := time.Now().UTC()
if len(namespaces) == 0 {
namespaces, err = h.ListNamespacesStr()
if err != nil {
log.Error().Caller().Err(err).Msg("failed to fetch all namespaces, failing to update last changed state.")
}
}
for _, namespace := range namespaces {
lastStateUpdate.WithLabelValues(namespace, "headscale").Set(float64(now.Unix()))
if h.lastStateChange == nil {
h.lastStateChange = xsync.NewMapOf[time.Time]()
}
h.lastStateChange.Store(namespace, now)
}
}
func (h *Headscale) getLastStateChange(namespaces ...string) time.Time {
times := []time.Time{}
// getLastStateChange takes a list of namespaces as a "filter", if no namespaces
// are past, then use the entier list of namespaces and look for the last update
if len(namespaces) > 0 {
for _, namespace := range namespaces {
if lastChange, ok := h.lastStateChange.Load(namespace); ok {
times = append(times, lastChange)
}
}
} else {
h.lastStateChange.Range(func(key string, value time.Time) bool {
times = append(times, value)
return true
})
}
sort.Slice(times, func(i, j int) bool {
return times[i].After(times[j])
})
log.Trace().Msgf("Latest times %#v", times)
if len(times) == 0 {
return time.Now().UTC()
} else {
return times[0]
}
}
func stdoutHandler(ctx *gin.Context) {
body, _ := io.ReadAll(ctx.Request.Body)
log.Trace().
Interface("header", ctx.Request.Header).
Interface("proto", ctx.Request.Proto).
Interface("url", ctx.Request.URL).
Bytes("body", body).
Msg("Request did not match")
}
func readOrCreatePrivateKey(path string) (*key.MachinePrivate, error) {
privateKey, err := os.ReadFile(path)
if errors.Is(err, os.ErrNotExist) {
log.Info().Str("path", path).Msg("No private key file at path, creating...")
machineKey := key.NewMachine()
machineKeyStr, err := machineKey.MarshalText()
if err != nil {
return nil, fmt.Errorf(
"failed to convert private key to string for saving: %w",
err,
)
}
err = os.WriteFile(path, machineKeyStr, privateKeyFileMode)
if err != nil {
return nil, fmt.Errorf(
"failed to save private key to disk: %w",
err,
)
}
return &machineKey, nil
} else if err != nil {
return nil, fmt.Errorf("failed to read private key file: %w", err)
}
trimmedPrivateKey := strings.TrimSpace(string(privateKey))
privateKeyEnsurePrefix := PrivateKeyEnsurePrefix(trimmedPrivateKey)
var machineKey key.MachinePrivate
if err = machineKey.UnmarshalText([]byte(privateKeyEnsurePrefix)); err != nil {
log.Info().
Str("path", path).
Msg("This might be due to a legacy (headscale pre-0.12) private key. " +
"If the key is in WireGuard format, delete the key and restart headscale. " +
"A new key will automatically be generated. All Tailscale clients will have to be restarted")
return nil, fmt.Errorf("failed to parse private key: %w", err)
}
return &machineKey, nil
}