api: add static router and improve path parser in rpc handler (#1437)

* api: add static router and improve path parser in rpc handler

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

* expose metadata context key to be able to get unmodified map keys

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

* server/grpc: fix jsonpb codec for protobuf msg

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

* api/handler/rpc: write 204 status code when rsp is nil

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

* api/handler/rpc: add check for nil response for non javascript

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

api/service/proto/api.pb.micro.go

@@ -0,0 +1,102 @@
+// Code generated by protoc-gen-micro. DO NOT EDIT.
+// source: api.proto
+
+package go_micro_api
+
+import (
+	fmt "fmt"
+	proto "github.com/golang/protobuf/proto"
+	math "math"
+)
+
+import (
+	context "context"
+	client "github.com/micro/go-micro/v2/client"
+	server "github.com/micro/go-micro/v2/server"
+)
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.ProtoPackageIsVersion3 // please upgrade the proto package
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ context.Context
+var _ client.Option
+var _ server.Option
+
+// Client API for Api service
+
+type ApiService interface {
+	Register(ctx context.Context, in *Endpoint, opts ...client.CallOption) (*EmptyResponse, error)
+	Deregister(ctx context.Context, in *Endpoint, opts ...client.CallOption) (*EmptyResponse, error)
+}
+
+type apiService struct {
+	c    client.Client
+	name string
+}
+
+func NewApiService(name string, c client.Client) ApiService {
+	return &apiService{
+		c:    c,
+		name: name,
+	}
+}
+
+func (c *apiService) Register(ctx context.Context, in *Endpoint, opts ...client.CallOption) (*EmptyResponse, error) {
+	req := c.c.NewRequest(c.name, "Api.Register", in)
+	out := new(EmptyResponse)
+	err := c.c.Call(ctx, req, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *apiService) Deregister(ctx context.Context, in *Endpoint, opts ...client.CallOption) (*EmptyResponse, error) {
+	req := c.c.NewRequest(c.name, "Api.Deregister", in)
+	out := new(EmptyResponse)
+	err := c.c.Call(ctx, req, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+// Server API for Api service
+
+type ApiHandler interface {
+	Register(context.Context, *Endpoint, *EmptyResponse) error
+	Deregister(context.Context, *Endpoint, *EmptyResponse) error
+}
+
+func RegisterApiHandler(s server.Server, hdlr ApiHandler, opts ...server.HandlerOption) error {
+	type api interface {
+		Register(ctx context.Context, in *Endpoint, out *EmptyResponse) error
+		Deregister(ctx context.Context, in *Endpoint, out *EmptyResponse) error
+	}
+	type Api struct {
+		api
+	}
+	h := &apiHandler{hdlr}
+	return s.Handle(s.NewHandler(&Api{h}, opts...))
+}
+
+type apiHandler struct {
+	ApiHandler
+}
+
+func (h *apiHandler) Register(ctx context.Context, in *Endpoint, out *EmptyResponse) error {
+	return h.ApiHandler.Register(ctx, in, out)
+}
+
+func (h *apiHandler) Deregister(ctx context.Context, in *Endpoint, out *EmptyResponse) error {
+	return h.ApiHandler.Deregister(ctx, in, out)
+}