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(),
 	}
 }