Fixed connection error handling by removing duplicated errors, standardizing on non-pointer error types

connection/errors.go

@@ -4,64 +4,51 @@ import (
 	"github.com/cloudflare/cloudflared/edgediscovery"
 	"github.com/cloudflare/cloudflared/h2mux"
 	tunnelpogs "github.com/cloudflare/cloudflared/tunnelrpc/pogs"
-	"github.com/prometheus/client_golang/prometheus"
 )
 
 const (
 	DuplicateConnectionError = "EDUPCONN"
 )
 
-// RegisterTunnel error from client
-type clientRegisterTunnelError struct {
-	cause error
-}
-
-func newRPCError(cause error, counter *prometheus.CounterVec, name rpcName) clientRegisterTunnelError {
-	counter.WithLabelValues(cause.Error(), string(name)).Inc()
-	return clientRegisterTunnelError{cause: cause}
-}
-
-func (e clientRegisterTunnelError) Error() string {
-	return e.cause.Error()
-}
-
 type DupConnRegisterTunnelError struct{}
 
-var errDuplicationConnection = &DupConnRegisterTunnelError{}
+var errDuplicationConnection = DupConnRegisterTunnelError{}
 
 func (e DupConnRegisterTunnelError) Error() string {
 	return "already connected to this server, trying another address"
 }
 
 // RegisterTunnel error from server
-type serverRegisterTunnelError struct {
-	cause     error
-	permanent bool
+type ServerRegisterTunnelError struct {
+	Cause     error
+	Permanent bool
 }
 
-func (e serverRegisterTunnelError) Error() string {
-	return e.cause.Error()
+func (e ServerRegisterTunnelError) Error() string {
+	return e.Cause.Error()
 }
 
-func serverRegistrationErrorFromRPC(err error) *serverRegisterTunnelError {
+func serverRegistrationErrorFromRPC(err error) ServerRegisterTunnelError {
 	if retryable, ok := err.(*tunnelpogs.RetryableError); ok {
-		return &serverRegisterTunnelError{
-			cause:     retryable.Unwrap(),
-			permanent: false,
+		return ServerRegisterTunnelError{
+			Cause:     retryable.Unwrap(),
+			Permanent: false,
 		}
 	}
-	return &serverRegisterTunnelError{
-		cause:     err,
-		permanent: true,
+	return ServerRegisterTunnelError{
+		Cause:     err,
+		Permanent: true,
 	}
 }
 
-type muxerShutdownError struct{}
+type MuxerShutdownError struct{}
 
-func (e muxerShutdownError) Error() string {
+func (e MuxerShutdownError) Error() string {
 	return "muxer shutdown"
 }
 
+var errMuxerStopped = MuxerShutdownError{}
+
 func isHandshakeErrRecoverable(err error, connIndex uint8, observer *Observer) bool {
 	log := observer.log.With().
 		Uint8(LogFieldConnIndex, connIndex).

connection/h2mux.go

@@ -143,7 +143,7 @@ func (h *h2muxConnection) serveMuxer(ctx context.Context) error {
 	// here to notify other routines to stop
 	err := h.muxer.Serve(ctx)
 	if err == nil {
-		return muxerShutdownError{}
+		return errMuxerStopped
 	}
 	return err
 }

connection/rpc.go

@@ -209,9 +209,9 @@ func (h *h2muxConnection) processRegisterTunnelError(err tunnelpogs.TunnelRegist
 		return errDuplicationConnection
 	}
 	h.observer.metrics.regFail.WithLabelValues("server_error", string(name)).Inc()
-	return serverRegisterTunnelError{
-		cause:     err,
-		permanent: err.IsPermanent(),
+	return ServerRegisterTunnelError{
+		Cause:     err,
+		Permanent: err.IsPermanent(),
 	}
 }
 

h2mux/muxmetrics.go

@@ -142,7 +142,7 @@ func (updater *muxMetricsUpdaterImpl) run(log *zerolog.Logger) error {
 	for {
 		select {
 		case <-updater.abortChan:
-			log.Info().Msgf("mux - metrics: Stopping mux metrics updater")
+			log.Debug().Msgf("mux - metrics: Stopping mux metrics updater")
 			return nil
 		case roundTripMeasurement := <-updater.updateRTTChan:
 			go updater.rttData.update(roundTripMeasurement)

origin/external_control.go

@@ -10,11 +10,11 @@ type ReconnectSignal struct {
 }
 
 // Error allows us to use ReconnectSignal as a special error to force connection abort
-func (r *ReconnectSignal) Error() string {
+func (r ReconnectSignal) Error() string {
 	return "reconnect signal"
 }
 
-func (r *ReconnectSignal) DelayBeforeReconnect() {
+func (r ReconnectSignal) DelayBeforeReconnect() {
 	if r.Delay > 0 {
 		time.Sleep(r.Delay)
 	}

origin/tunnel.go

@@ -63,31 +63,6 @@ type TunnelConfig struct {
 	EdgeTLSConfigs   map[connection.Protocol]*tls.Config
 }
 
-type muxerShutdownError struct{}
-
-func (e muxerShutdownError) Error() string {
-	return "muxer shutdown"
-}
-
-// RegisterTunnel error from server
-type serverRegisterTunnelError struct {
-	cause     error
-	permanent bool
-}
-
-func (e serverRegisterTunnelError) Error() string {
-	return e.cause.Error()
-}
-
-// RegisterTunnel error from client
-type clientRegisterTunnelError struct {
-	cause error
-}
-
-func (e clientRegisterTunnelError) Error() string {
-	return e.cause.Error()
-}
-
 func (c *TunnelConfig) RegistrationOptions(connectionID uint8, OriginLocalIP string, uuid uuid.UUID) *tunnelpogs.RegistrationOptions {
 	policy := tunnelrpc.ExistingTunnelPolicy_balance
 	if c.HAConnections <= 1 && c.LBPool == "" {
@@ -348,24 +323,24 @@ func ServeH2mux(
 	err = errGroup.Wait()
 	if err != nil {
 		switch err := err.(type) {
-		case *connection.DupConnRegisterTunnelError:
-			// don't retry this connection anymore, let supervisor pick new a address
+		case connection.DupConnRegisterTunnelError:
+			// don't retry this connection anymore, let supervisor pick a new address
 			return err, false
-		case *serverRegisterTunnelError:
+		case connection.ServerRegisterTunnelError:
 			log.Err(err).Msg("Register tunnel error from server side")
 			// Don't send registration error return from server to Sentry. They are
 			// logged on server side
 			if incidents := config.IncidentLookup.ActiveIncidents(); len(incidents) > 0 {
 				log.Error().Msg(activeIncidentsMsg(incidents))
 			}
-			return err.cause, !err.permanent
-		case *clientRegisterTunnelError:
-			log.Err(err).Msg("Register tunnel error on client side")
+			return err.Cause, !err.Permanent
+		case connection.MuxerShutdownError:
+			if handler.StoppedGracefully() {
+				return nil, false
+			}
+			log.Info().Msg("Unexpected muxer shutdown")
 			return err, true
-		case *muxerShutdownError:
-			log.Info().Msg("Muxer shutdown")
-			return err, true
-		case *ReconnectSignal:
+		case ReconnectSignal:
 			log.Info().
 				Uint8(connection.LogFieldConnIndex, connIndex).
 				Msgf("Restarting connection due to reconnect signal in %s", err.Delay)