asim-micro更改服务协议transport grpc后，使用rpc调用出错解决

// filepath：option.go

func newOptions(opts ...Option) Options {
	opt := Options{
		Auth:      auth.DefaultAuth,
		Broker:    broker.DefaultBroker,
		Cmd:       cmd.DefaultCmd,
		Config:    config.DefaultConfig,
		Client:    client.DefaultClient,
		Server:    server.DefaultServer,
		Store:     store.DefaultStore,
		Registry:  registry.DefaultRegistry,
		Runtime:   runtime.DefaultRuntime,
		Transport: transport.DefaultTransport, //默认使用http
		Context:   context.Background(),
		Signal:    true,
	}

	for _, o := range opts {
		o(&opt)
	}

	return opt
}

// filepath： transport/transport.go

var (
	DefaultTransport Transport = NewHTTPTransport()

	DefaultDialTimeout = time.Second * 5
)

// 使用grpc代替http

import grpcT "github.com/asim/go-micro/plugins/transport/grpc/v3"

micro.Transport(grpcT.NewTransport()),

// filepath：plugins/client/grpc/grpc.go

func (g *grpcClient) call(ctx context.Context, node *registry.Node, req client.Request, rsp interface{}, opts client.CallOptions) error {
	var header map[string]string

	address := node.Address

	header = make(map[string]string)
	if md, ok := metadata.FromContext(ctx); ok {
		header = make(map[string]string, len(md))
		for k, v := range md {
			header[strings.ToLower(k)] = v
		}
	} else {
		header = make(map[string]string)
	}

	// set timeout in nanoseconds
	header["timeout"] = fmt.Sprintf("%d", opts.RequestTimeout)
	// set the content type for the request
	header["x-content-type"] = req.ContentType()

	md := gmetadata.New(header)
	ctx = gmetadata.NewOutgoingContext(ctx, md)

	cf, err := g.newGRPCCodec(req.ContentType())
	if err != nil {
		return errors.InternalServerError("go.micro.client", err.Error())
	}

	maxRecvMsgSize := g.maxRecvMsgSizeValue()
	maxSendMsgSize := g.maxSendMsgSizeValue()

	var grr error

	grpcDialOptions := []grpc.DialOption{
		grpc.WithTimeout(opts.DialTimeout),
		g.secure(address),
		grpc.WithDefaultCallOptions(
			grpc.MaxCallRecvMsgSize(maxRecvMsgSize),
			grpc.MaxCallSendMsgSize(maxSendMsgSize),
		),
	}

	if opts := g.getGrpcDialOptions(); opts != nil {
		grpcDialOptions = append(grpcDialOptions, opts...)
	}

	cc, err := g.pool.getConn(address, grpcDialOptions...)
	if err != nil {
		return errors.InternalServerError("go.micro.client", fmt.Sprintf("Error sending request: %v", err))
	}
	defer func() {
		// defer execution of release
		g.pool.release(address, cc, grr)
	}()

	ch := make(chan error, 1)

	go func() {
		grpcCallOptions := []grpc.CallOption{
			grpc.ForceCodec(cf),
			grpc.CallContentSubtype(cf.Name())}
		if opts := g.getGrpcCallOptions(); opts != nil {
			grpcCallOptions = append(grpcCallOptions, opts...)
		}
		err := cc.Invoke(ctx, methodToGRPC(req.Service(), req.Endpoint()), req.Body(), rsp, grpcCallOptions...)
		ch <- microError(err)
	}()

	select {
	case err := <-ch:
		grr = err
	case <-ctx.Done():
		grr = errors.Timeout("go.micro.client", "%v", ctx.Err())
	}

	return grr
}

err := cc.Invoke(ctx, methodToGRPC(req.Service(), req.Endpoint()), req.Body(), rsp, grpcCallOptions...)

// service Struct.Method /service.Struct/Method
func methodToGRPC(service, method string) string {
	// no method or already grpc method
	if len(method) == 0 || method[0] == '/' {
		return method
	}

	// assume method is Foo.Bar
	mParts := strings.Split(method, ".")
	if len(mParts) != 2 {
		return method
	}

	if len(service) == 0 {
		return fmt.Sprintf("/%s/%s", mParts[0], mParts[1])
	}

	// return /pkg.Foo/Bar
        // 从这里可以看到 将endpoint按.分割，第一个参数连接servicename
        return fmt.Sprintf("/%s.%s/%s", service, mParts[0], mParts[1])

 }

// 调整代码，问题解决
return fmt.Sprintf("/%s/%s.%s", service, mParts[0], mParts[1])