support chain proxy for grpc

transport/internet/grpc/dial.go

@@ -50,7 +50,7 @@ func dialgRPC(ctx context.Context, dest net.Destination, streamSettings *interne
 		dialOption = grpc.WithTransportCredentials(credentials.NewTLS(config.GetTLSConfig()))
 	}
 
-	conn, err := getGrpcClient(dest, dialOption)
+	conn, err := getGrpcClient(ctx, dest, dialOption)
 
 	if err != nil {
 		return nil, newError("Cannot dial grpc").Base(err)
@@ -63,7 +63,7 @@ func dialgRPC(ctx context.Context, dest net.Destination, streamSettings *interne
 	return encoding.NewGunConn(gunService, nil), nil
 }
 
-func getGrpcClient(dest net.Destination, dialOption grpc.DialOption) (*grpc.ClientConn, error) {
+func getGrpcClient(ctx context.Context, dest net.Destination, dialOption grpc.DialOption) (*grpc.ClientConn, error) {
 	globalDialerAccess.Lock()
 	defer globalDialerAccess.Unlock()
 
@@ -71,6 +71,7 @@ func getGrpcClient(dest net.Destination, dialOption grpc.DialOption) (*grpc.Clie
 		globalDialerMap = make(map[net.Destination]*grpc.ClientConn)
 	}
 
+	//TODO Should support chain proxy to the same destination
 	if client, found := globalDialerMap[dest]; found && client.GetState() != connectivity.Shutdown {
 		return client, nil
 	}
@@ -87,7 +88,7 @@ func getGrpcClient(dest net.Destination, dialOption grpc.DialOption) (*grpc.Clie
 			},
 			MinConnectTimeout: 5 * time.Second,
 		}),
-		grpc.WithContextDialer(func(ctx context.Context, s string) (gonet.Conn, error) {
+		grpc.WithContextDialer(func(ctxGrpc context.Context, s string) (gonet.Conn, error) {
 			rawHost, rawPort, err := net.SplitHostPort(s)
 			if err != nil {
 				return nil, err