TUN-2940: Added delay parameter to stdin reconnect command.

cmd/cloudflared/tunnel/cmd.go

@@ -11,6 +11,7 @@ import (
 	"reflect"
 	"runtime"
 	"runtime/trace"
+	"strings"
 	"sync"
 	"time"
 
@@ -421,7 +422,7 @@ func StartServer(c *cli.Context, version string, shutdownC, graceShutdownC chan
 		return err
 	}
 
-	reconnectCh := make(chan struct{}, 1)
+	reconnectCh := make(chan origin.ReconnectSignal, 1)
 	if c.IsSet("stdin-control") {
 		logger.Warn("Enabling control through stdin")
 		go stdinControl(reconnectCh)
@@ -1112,17 +1113,34 @@ func tunnelFlags(shouldHide bool) []cli.Flag {
 	}
 }
 
-func stdinControl(reconnectCh chan struct{}) {
+func stdinControl(reconnectCh chan origin.ReconnectSignal) {
 	for {
 		scanner := bufio.NewScanner(os.Stdin)
 		for scanner.Scan() {
 			command := scanner.Text()
+			parts := strings.SplitN(command, " ", 2)
 
-			switch command {
+			switch parts[0] {
+			case "":
+				break
 			case "reconnect":
-				reconnectCh <- struct{}{}
+				var reconnect origin.ReconnectSignal
+				if len(parts) > 1 {
+					var err error
+					if reconnect.Delay, err = time.ParseDuration(parts[1]); err != nil {
+						logger.Error(err.Error())
+						continue
+					}
+				}
+				logger.Infof("Sending reconnect signal %+v", reconnect)
+				reconnectCh <- reconnect
 			default:
 				logger.Warn("Unknown command: ", command)
+				fallthrough
+			case "help":
+				logger.Info(`Supported command: 
+reconnect [delay] 
+- restarts one randomly chosen connection with optional delay before reconnect`)
 			}
 		}
 	}

origin/external_control.go

@@ -0,0 +1,21 @@
+package origin
+
+import (
+	"time"
+)
+
+type ReconnectSignal struct {
+	// wait this many seconds before re-establish the connection
+	Delay time.Duration
+}
+
+// Error allows us to use ReconnectSignal as a special error to force connection abort
+func (r *ReconnectSignal) Error() string {
+	return "reconnect signal"
+}
+
+func (r *ReconnectSignal) DelayBeforeReconnect() {
+	if r.Delay > 0 {
+		time.Sleep(r.Delay)
+	}
+}

origin/supervisor.go

@@ -105,7 +105,7 @@ func NewSupervisor(config *TunnelConfig, u uuid.UUID) (*Supervisor, error) {
 	}, nil
 }
 
-func (s *Supervisor) Run(ctx context.Context, connectedSignal *signal.Signal, reconnectCh chan struct{}) error {
+func (s *Supervisor) Run(ctx context.Context, connectedSignal *signal.Signal, reconnectCh chan ReconnectSignal) error {
 	logger := s.config.Logger
 	if err := s.initialize(ctx, connectedSignal, reconnectCh); err != nil {
 		return err
@@ -191,7 +191,7 @@ func (s *Supervisor) Run(ctx context.Context, connectedSignal *signal.Signal, re
 }
 
 // Returns nil if initialization succeeded, else the initialization error.
-func (s *Supervisor) initialize(ctx context.Context, connectedSignal *signal.Signal, reconnectCh chan struct{}) error {
+func (s *Supervisor) initialize(ctx context.Context, connectedSignal *signal.Signal, reconnectCh chan ReconnectSignal) error {
 	logger := s.logger
 
 	s.lastResolve = time.Now()
@@ -221,7 +221,7 @@ func (s *Supervisor) initialize(ctx context.Context, connectedSignal *signal.Sig
 
 // startTunnel starts the first tunnel connection. The resulting error will be sent on
 // s.tunnelErrors. It will send a signal via connectedSignal if registration succeed
-func (s *Supervisor) startFirstTunnel(ctx context.Context, connectedSignal *signal.Signal, reconnectCh chan struct{}) {
+func (s *Supervisor) startFirstTunnel(ctx context.Context, connectedSignal *signal.Signal, reconnectCh chan ReconnectSignal) {
 	var (
 		addr *net.TCPAddr
 		err  error
@@ -265,7 +265,7 @@ func (s *Supervisor) startFirstTunnel(ctx context.Context, connectedSignal *sign
 
 // startTunnel starts a new tunnel connection. The resulting error will be sent on
 // s.tunnelErrors.
-func (s *Supervisor) startTunnel(ctx context.Context, index int, connectedSignal *signal.Signal, reconnectCh chan struct{}) {
+func (s *Supervisor) startTunnel(ctx context.Context, index int, connectedSignal *signal.Signal, reconnectCh chan ReconnectSignal) {
 	var (
 		addr *net.TCPAddr
 		err  error

origin/tunnel.go

@@ -179,7 +179,7 @@ func (c *TunnelConfig) SupportedFeatures() []string {
 	return basic
 }
 
-func StartTunnelDaemon(ctx context.Context, config *TunnelConfig, connectedSignal *signal.Signal, cloudflaredID uuid.UUID, reconnectCh chan struct{}) error {
+func StartTunnelDaemon(ctx context.Context, config *TunnelConfig, connectedSignal *signal.Signal, cloudflaredID uuid.UUID, reconnectCh chan ReconnectSignal) error {
 	s, err := NewSupervisor(config, cloudflaredID)
 	if err != nil {
 		return err
@@ -195,7 +195,7 @@ func ServeTunnelLoop(ctx context.Context,
 	connectedSignal *signal.Signal,
 	u uuid.UUID,
 	bufferPool *buffer.Pool,
-	reconnectCh chan struct{},
+	reconnectCh chan ReconnectSignal,
 ) error {
 	connectionLogger := config.Logger.WithField("connectionID", connectionID)
 	config.Metrics.incrementHaConnections()
@@ -244,7 +244,7 @@ func ServeTunnel(
 	backoff *BackoffHandler,
 	u uuid.UUID,
 	bufferPool *buffer.Pool,
-	reconnectCh chan struct{},
+	reconnectCh chan ReconnectSignal,
 ) (err error, recoverable bool) {
 	// Treat panics as recoverable errors
 	defer func() {
@@ -332,13 +332,14 @@ func ServeTunnel(
 	})
 
 	errGroup.Go(func() error {
+		for {
 			select {
-		case <-reconnectCh:
-			return fmt.Errorf("received disconnect signal")
+			case reconnect := <-reconnectCh:
+				return &reconnect
 			case <-serveCtx.Done():
 				return nil
 			}
-
+		}
 	})
 
 	errGroup.Go(func() error {
@@ -372,7 +373,11 @@ func ServeTunnel(
 			logger.WithError(castedErr.cause).Error("Register tunnel error on client side")
 			return err, true
 		case muxerShutdownError:
-			logger.Infof("Muxer shutdown")
+			logger.Info("Muxer shutdown")
+			return err, true
+		case *ReconnectSignal:
+			logger.Warnf("Restarting due to reconnect signal in %d seconds", castedErr.Delay)
+			castedErr.DelayBeforeReconnect()
 			return err, true
 		default:
 			logger.WithError(err).Error("Serve tunnel error")

sshlog/logger_test.go

@@ -32,7 +32,7 @@ func createLogger(t *testing.T) *Logger {
 //	}()
 //
 //	logger.Write([]byte(testStr))
-//	time.Sleep(2 * time.Millisecond)
+//	time.DelayBeforeReconnect(2 * time.Millisecond)
 //	data, err := ioutil.ReadFile(logFileName)
 //	if err != nil {
 //		t.Fatal("couldn't read the log file!", err)