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/api.go

@@ -9,6 +9,20 @@ import (
 	"github.com/micro/go-micro/v2/server"
 )
 
+type Api interface {
+	// Register a http handler
+	Register(*Endpoint) error
+	// Register a route
+	Deregister(*Endpoint) error
+	// Init initialises the command line.
+	// It also parses further options.
+	//Init(...Option) error
+	// Options
+	//Options() Options
+	// String
+	String() string
+}
+
 // Endpoint is a mapping between an RPC method and HTTP endpoint
 type Endpoint struct {
 	// RPC Method e.g. Greeter.Hello
@@ -23,6 +37,8 @@ type Endpoint struct {
 	Method []string
 	// HTTP Path e.g /greeter. Expect POSIX regex
 	Path []string
+	// Stream flag
+	Stream bool
 }
 
 // Service represents an API service

api/grpc_test.go

@@ -0,0 +1,132 @@
+package api_test
+
+import (
+	"context"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"testing"
+	"time"
+
+	"github.com/micro/go-micro/v2"
+	"github.com/micro/go-micro/v2/api"
+	ahandler "github.com/micro/go-micro/v2/api/handler"
+	apirpc "github.com/micro/go-micro/v2/api/handler/rpc"
+	"github.com/micro/go-micro/v2/api/router"
+	rstatic "github.com/micro/go-micro/v2/api/router/static"
+	bmemory "github.com/micro/go-micro/v2/broker/memory"
+	"github.com/micro/go-micro/v2/client"
+	gcli "github.com/micro/go-micro/v2/client/grpc"
+	rmemory "github.com/micro/go-micro/v2/registry/memory"
+	"github.com/micro/go-micro/v2/server"
+	gsrv "github.com/micro/go-micro/v2/server/grpc"
+	tgrpc "github.com/micro/go-micro/v2/transport/grpc"
+
+	pb "github.com/micro/go-micro/v2/server/grpc/proto"
+)
+
+// server is used to implement helloworld.GreeterServer.
+type testServer struct {
+	msgCount int
+}
+
+// TestHello implements helloworld.GreeterServer
+func (s *testServer) Call(ctx context.Context, req *pb.Request, rsp *pb.Response) error {
+	rsp.Msg = "Hello " + req.Name
+	return nil
+}
+
+func TestApiAndGRPC(t *testing.T) {
+	r := rmemory.NewRegistry()
+	b := bmemory.NewBroker()
+	tr := tgrpc.NewTransport()
+	s := gsrv.NewServer(
+		server.Broker(b),
+		server.Name("foo"),
+		server.Registry(r),
+		server.Transport(tr),
+	)
+	c := gcli.NewClient(
+		client.Registry(r),
+		client.Broker(b),
+		client.Transport(tr),
+	)
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	svc := micro.NewService(
+		micro.Server(s),
+		micro.Client(c),
+		micro.Broker(b),
+		micro.Registry(r),
+		micro.Transport(tr),
+		micro.Context(ctx))
+	h := &testServer{}
+	pb.RegisterTestHandler(s, h)
+
+	go func() {
+		if err := svc.Run(); err != nil {
+			t.Fatalf("failed to start: %v", err)
+		}
+	}()
+	time.Sleep(1 * time.Second)
+	// check registration
+	services, err := r.GetService("foo")
+	if err != nil || len(services) == 0 {
+		t.Fatalf("failed to get service: %v # %d", err, len(services))
+	}
+
+	router := rstatic.NewRouter(
+		router.WithHandler(apirpc.Handler),
+		router.WithRegistry(svc.Server().Options().Registry),
+	)
+	err = router.Register(&api.Endpoint{
+		Name:    "foo.Test.Call",
+		Method:  []string{"GET"},
+		Path:    []string{"/api/v0/test/call/{name}"},
+		Handler: "rpc",
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	hrpc := apirpc.NewHandler(
+		ahandler.WithService(svc),
+		ahandler.WithRouter(router),
+	)
+
+	hsrv := &http.Server{
+		Handler:        hrpc,
+		Addr:           "127.0.0.1:6543",
+		WriteTimeout:   15 * time.Second,
+		ReadTimeout:    15 * time.Second,
+		IdleTimeout:    20 * time.Second,
+		MaxHeaderBytes: 1024 * 1024 * 1, // 1Mb
+	}
+
+	go func() {
+		log.Println(hsrv.ListenAndServe())
+	}()
+
+	time.Sleep(1 * time.Second)
+	rsp, err := http.Get(fmt.Sprintf("http://%s/api/v0/test/call/TEST", hsrv.Addr))
+	if err != nil {
+		t.Fatalf("Failed to created http.Request: %v", err)
+	}
+	defer rsp.Body.Close()
+	buf, err := ioutil.ReadAll(rsp.Body)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	jsonMsg := `{"msg":"Hello TEST"}`
+	if string(buf) != jsonMsg {
+		t.Fatalf("invalid message received, parsing error %s != %s", buf, jsonMsg)
+	}
+	select {
+	case <-ctx.Done():
+		return
+	}
+
+}

api/handler/rpc/rpc.go

@@ -12,7 +12,7 @@ import (
 	"github.com/joncalhoun/qson"
 	"github.com/micro/go-micro/v2/api"
 	"github.com/micro/go-micro/v2/api/handler"
-	proto "github.com/micro/go-micro/v2/api/internal/proto"
+	"github.com/micro/go-micro/v2/api/internal/proto"
 	"github.com/micro/go-micro/v2/client"
 	"github.com/micro/go-micro/v2/client/selector"
 	"github.com/micro/go-micro/v2/codec"
@@ -20,6 +20,7 @@ import (
 	"github.com/micro/go-micro/v2/codec/protorpc"
 	"github.com/micro/go-micro/v2/errors"
 	"github.com/micro/go-micro/v2/logger"
+	"github.com/micro/go-micro/v2/metadata"
 	"github.com/micro/go-micro/v2/registry"
 	"github.com/micro/go-micro/v2/util/ctx"
 	"github.com/oxtoacart/bpool"
@@ -128,7 +129,6 @@ func (h *rpcHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	so := selector.WithStrategy(strategy(service.Services))
 
 	// walk the standard call path
-
 	// get payload
 	br, err := requestPayload(r)
 	if err != nil {
@@ -164,7 +164,12 @@ func (h *rpcHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		}
 
 		// marshall response
-		rsp, _ = response.Marshal()
+		rsp, err = response.Marshal()
+		if err != nil {
+			writeError(w, r, err)
+			return
+		}
+
 	default:
 		// if json codec is not present set to json
 		if !hasCodec(ct, jsonCodecs) {
@@ -195,7 +200,11 @@ func (h *rpcHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		}
 
 		// marshall response
-		rsp, _ = response.MarshalJSON()
+		rsp, err = response.MarshalJSON()
+		if err != nil {
+			writeError(w, r, err)
+			return
+		}
 	}
 
 	// write the response
@@ -219,8 +228,11 @@ func hasCodec(ct string, codecs []string) bool {
 // If the request is a GET the query string parameters are extracted and marshaled to JSON and the raw bytes are returned.
 // If the request method is a POST the request body is read and returned
 func requestPayload(r *http.Request) ([]byte, error) {
+	var err error
+
 	// we have to decode json-rpc and proto-rpc because we suck
 	// well actually because there's no proxy codec right now
+
 	ct := r.Header.Get("Content-Type")
 	switch {
 	case strings.Contains(ct, "application/json-rpc"):
@@ -229,11 +241,11 @@ func requestPayload(r *http.Request) ([]byte, error) {
 			Header: make(map[string]string),
 		}
 		c := jsonrpc.NewCodec(&buffer{r.Body})
-		if err := c.ReadHeader(&msg, codec.Request); err != nil {
+		if err = c.ReadHeader(&msg, codec.Request); err != nil {
 			return nil, err
 		}
 		var raw json.RawMessage
-		if err := c.ReadBody(&raw); err != nil {
+		if err = c.ReadBody(&raw); err != nil {
 			return nil, err
 		}
 		return ([]byte)(raw), nil
@@ -243,15 +255,14 @@ func requestPayload(r *http.Request) ([]byte, error) {
 			Header: make(map[string]string),
 		}
 		c := protorpc.NewCodec(&buffer{r.Body})
-		if err := c.ReadHeader(&msg, codec.Request); err != nil {
+		if err = c.ReadHeader(&msg, codec.Request); err != nil {
 			return nil, err
 		}
 		var raw proto.Message
-		if err := c.ReadBody(&raw); err != nil {
+		if err = c.ReadBody(&raw); err != nil {
 			return nil, err
 		}
-		b, err := raw.Marshal()
+		return raw.Marshal()
-		return b, err
 	case strings.Contains(ct, "application/www-x-form-urlencoded"):
 		r.ParseForm()
 
@@ -262,43 +273,94 @@ func requestPayload(r *http.Request) ([]byte, error) {
 		}
 
 		// marshal
-		b, err := json.Marshal(vals)
+		return json.Marshal(vals)
-		return b, err
 		// TODO: application/grpc
 	}
 
 	// otherwise as per usual
+	ctx := r.Context()
+	// dont user meadata.FromContext as it mangles names
+	md, ok := ctx.Value(metadata.MetadataKey{}).(metadata.Metadata)
+	if !ok {
+		md = make(map[string]string)
+	}
+	// allocate maximum
+	matches := make(map[string]string, len(md))
+	for k, v := range md {
+		if strings.HasPrefix(k, "x-api-field-") {
+			matches[strings.TrimPrefix(k, "x-api-field-")] = v
+		}
+		delete(md, k)
+	}
+
+	// restore context without fields
+	ctx = metadata.NewContext(ctx, md)
+	*r = *r.WithContext(ctx)
+	req := make(map[string]interface{}, len(md))
+	for k, v := range matches {
+		ps := strings.Split(k, ".")
+		if len(ps) == 1 {
+			req[k] = v
+			continue
+		}
+
+		em := make(map[string]interface{})
+		em[ps[len(ps)-1]] = v
+		for i := len(ps) - 2; i > 0; i-- {
+			nm := make(map[string]interface{})
+			nm[ps[i]] = em
+			em = nm
+		}
+		req[ps[0]] = em
+	}
+	pathbuf := []byte("{}")
+	if len(req) > 0 {
+		pathbuf, err = json.Marshal(req)
+		if err != nil {
+			return nil, err
+		}
+	}
+	urlbuf := []byte("{}")
+	if len(r.URL.RawQuery) > 0 {
+		urlbuf, err = qson.ToJSON(r.URL.RawQuery)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	out, err := jsonpatch.MergeMergePatches(urlbuf, pathbuf)
+	if err != nil {
+		return nil, err
+	}
 
 	switch r.Method {
 	case "GET":
-		if len(r.URL.RawQuery) > 0 {
+		// empty response
-			return qson.ToJSON(r.URL.RawQuery)
+		if strings.Contains(ct, "application/json") && string(out) == "{}" {
+			return out, nil
+		} else if string(out) == "{}" && !strings.Contains(ct, "application/json") {
+			return []byte{}, nil
 		}
+		return out, nil
 	case "PATCH", "POST", "PUT", "DELETE":
-		urlParams := []byte("{}")
+		bodybuf := []byte("{}")
-		bodyParams := []byte("{}")
-		var err error
-		if len(r.URL.RawQuery) > 0 {
-			if urlParams, err = qson.ToJSON(r.URL.RawQuery); err != nil {
-				return nil, err
-			}
-		}
-
 		buf := bufferPool.Get()
 		defer bufferPool.Put(buf)
 		if _, err := buf.ReadFrom(r.Body); err != nil {
 			return nil, err
 		}
 		if b := buf.Bytes(); len(b) > 0 {
-			bodyParams = b
+			bodybuf = b
+		} else {
+			return []byte{}, nil
 		}
 
-		if out, err := jsonpatch.MergeMergePatches(urlParams, bodyParams); err == nil {
+		if out, err = jsonpatch.MergeMergePatches(out, bodybuf); err == nil {
 			return out, nil
 		}
 
 		//fallback to previous unknown behaviour
-		return buf.Bytes(), nil
+		return bodybuf, nil
 
 	}
 
@@ -332,7 +394,7 @@ func writeError(w http.ResponseWriter, r *http.Request, err error) {
 	}
 
 	_, werr := w.Write([]byte(ce.Error()))
-	if err != nil {
+	if werr != nil {
 		if logger.V(logger.ErrorLevel, logger.DefaultLogger) {
 			logger.Error(werr)
 		}
@@ -351,6 +413,11 @@ func writeResponse(w http.ResponseWriter, r *http.Request, rsp []byte) {
 		w.Header().Set("grpc-message", "")
 	}
 
+	// write 204 status if rsp is nil
+	if len(rsp) == 0 {
+		w.WriteHeader(http.StatusNoContent)
+	}
+
 	// write response
 	_, err := w.Write(rsp)
 	if err != nil {

api/router/registry/registry.go

@@ -250,6 +250,14 @@ func (r *registryRouter) Close() error {
 	return nil
 }
 
+func (r *registryRouter) Register(ep *api.Endpoint) error {
+	return nil
+}
+
+func (r *registryRouter) Deregister(ep *api.Endpoint) error {
+	return nil
+}
+
 func (r *registryRouter) Endpoint(req *http.Request) (*api.Service, error) {
 	if r.isClosed() {
 		return nil, errors.New("router closed")

api/router/router.go

@@ -15,6 +15,10 @@ type Router interface {
 	Close() error
 	// Endpoint returns an api.Service endpoint or an error if it does not exist
 	Endpoint(r *http.Request) (*api.Service, error)
+	// Register endpoint in router
+	Register(ep *api.Endpoint) error
+	// Deregister endpoint from router
+	Deregister(ep *api.Endpoint) error
 	// Route returns an api.Service route
 	Route(r *http.Request) (*api.Service, error)
 }

api/router/static/static.go

@@ -0,0 +1,304 @@
+package static
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+	"regexp"
+	"strings"
+	"sync"
+
+	"github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway/httprule"
+	"github.com/grpc-ecosystem/grpc-gateway/runtime"
+	"github.com/micro/go-micro/v2/api"
+	"github.com/micro/go-micro/v2/api/router"
+	"github.com/micro/go-micro/v2/logger"
+	"github.com/micro/go-micro/v2/metadata"
+)
+
+type endpoint struct {
+	apiep    *api.Endpoint
+	hostregs []*regexp.Regexp
+	pathregs []runtime.Pattern
+}
+
+// router is the default router
+type staticRouter struct {
+	exit chan bool
+	opts router.Options
+	sync.RWMutex
+	eps map[string]*endpoint
+}
+
+func (r *staticRouter) isClosed() bool {
+	select {
+	case <-r.exit:
+		return true
+	default:
+		return false
+	}
+}
+
+/*
+// watch for endpoint changes
+func (r *staticRouter) watch() {
+	var attempts int
+
+	for {
+		if r.isClosed() {
+			return
+		}
+
+		// watch for changes
+		w, err := r.opts.Registry.Watch()
+		if err != nil {
+			attempts++
+			log.Println("Error watching endpoints", err)
+			time.Sleep(time.Duration(attempts) * time.Second)
+			continue
+		}
+
+		ch := make(chan bool)
+
+		go func() {
+			select {
+			case <-ch:
+				w.Stop()
+			case <-r.exit:
+				w.Stop()
+			}
+		}()
+
+		// reset if we get here
+		attempts = 0
+
+		for {
+			// process next event
+			res, err := w.Next()
+			if err != nil {
+				log.Println("Error getting next endpoint", err)
+				close(ch)
+				break
+			}
+			r.process(res)
+		}
+	}
+}
+*/
+
+func (r *staticRouter) Register(ep *api.Endpoint) error {
+	if err := api.Validate(ep); err != nil {
+		return err
+	}
+
+	var pathregs []runtime.Pattern
+	var hostregs []*regexp.Regexp
+
+	for _, h := range ep.Host {
+		if h == "" || h == "*" {
+			continue
+		}
+		hostreg, err := regexp.CompilePOSIX(h)
+		if err != nil {
+			return err
+		}
+		hostregs = append(hostregs, hostreg)
+	}
+
+	for _, p := range ep.Path {
+		rule, err := httprule.Parse(p)
+		if err != nil {
+			return err
+		}
+		tpl := rule.Compile()
+		pathreg, err := runtime.NewPattern(tpl.Version, tpl.OpCodes, tpl.Pool, "")
+		if err != nil {
+			return err
+		}
+		pathregs = append(pathregs, pathreg)
+	}
+
+	r.Lock()
+	r.eps[ep.Name] = &endpoint{apiep: ep, pathregs: pathregs, hostregs: hostregs}
+	r.Unlock()
+	return nil
+}
+
+func (r *staticRouter) Deregister(ep *api.Endpoint) error {
+	if err := api.Validate(ep); err != nil {
+		return err
+	}
+	r.Lock()
+	delete(r.eps, ep.Name)
+	r.Unlock()
+	return nil
+}
+
+func (r *staticRouter) Options() router.Options {
+	return r.opts
+}
+
+func (r *staticRouter) Close() error {
+	select {
+	case <-r.exit:
+		return nil
+	default:
+		close(r.exit)
+	}
+	return nil
+}
+
+func (r *staticRouter) Endpoint(req *http.Request) (*api.Service, error) {
+	ep, err := r.endpoint(req)
+	if err != nil {
+		return nil, err
+	}
+
+	epf := strings.Split(ep.apiep.Name, ".")
+	services, err := r.opts.Registry.GetService(epf[0])
+	if err != nil {
+		return nil, err
+	}
+
+	// hack for stream endpoint
+	if ep.apiep.Stream {
+		for _, svc := range services {
+			for _, e := range svc.Endpoints {
+				e.Name = strings.Join(epf[1:], ".")
+				e.Metadata = make(map[string]string)
+				e.Metadata["stream"] = "true"
+			}
+		}
+	}
+
+	svc := &api.Service{
+		Name: epf[0],
+		Endpoint: &api.Endpoint{
+			Name:    strings.Join(epf[1:], "."),
+			Handler: "rpc",
+			Host:    ep.apiep.Host,
+			Method:  ep.apiep.Method,
+			Path:    ep.apiep.Path,
+		},
+		Services: services,
+	}
+
+	return svc, nil
+}
+
+func (r *staticRouter) endpoint(req *http.Request) (*endpoint, error) {
+	if r.isClosed() {
+		return nil, errors.New("router closed")
+	}
+
+	r.RLock()
+	defer r.RUnlock()
+
+	var idx int
+	if len(req.URL.Path) > 0 && req.URL.Path != "/" {
+		idx = 1
+	}
+	path := strings.Split(req.URL.Path[idx:], "/")
+	// use the first match
+	// TODO: weighted matching
+
+	for _, ep := range r.eps {
+		var mMatch, hMatch, pMatch bool
+
+		// 1. try method
+	methodLoop:
+		for _, m := range ep.apiep.Method {
+			if m == req.Method {
+				mMatch = true
+				break methodLoop
+			}
+		}
+		if !mMatch {
+			continue
+		}
+		if logger.V(logger.DebugLevel, logger.DefaultLogger) {
+			logger.Debugf("api method match %s", req.Method)
+		}
+
+		// 2. try host
+		if len(ep.apiep.Host) == 0 {
+			hMatch = true
+		} else {
+		hostLoop:
+			for idx, h := range ep.apiep.Host {
+				if h == "" || h == "*" {
+					hMatch = true
+					break hostLoop
+				} else {
+					if ep.hostregs[idx].MatchString(req.URL.Host) {
+						hMatch = true
+						break hostLoop
+					}
+				}
+			}
+		}
+		if !hMatch {
+			continue
+		}
+		if logger.V(logger.DebugLevel, logger.DefaultLogger) {
+			logger.Debugf("api host match %s", req.URL.Host)
+		}
+
+		// 3. try path
+	pathLoop:
+		for _, pathreg := range ep.pathregs {
+			matches, err := pathreg.Match(path, "")
+			if err != nil {
+				// TODO: log error
+				continue
+			}
+			pMatch = true
+			ctx := req.Context()
+			md, ok := metadata.FromContext(ctx)
+			if !ok {
+				md = make(metadata.Metadata)
+			}
+			for k, v := range matches {
+				md[fmt.Sprintf("x-api-field-%s", k)] = v
+			}
+			*req = *req.WithContext(context.WithValue(ctx, metadata.MetadataKey{}, md))
+			break pathLoop
+		}
+		if !pMatch {
+			continue
+		}
+		// TODO: Percentage traffic
+
+		// we got here, so its a match
+		return ep, nil
+	}
+	// no match
+	return nil, fmt.Errorf("endpoint not found for %v", req)
+}
+
+func (r *staticRouter) Route(req *http.Request) (*api.Service, error) {
+	if r.isClosed() {
+		return nil, errors.New("router closed")
+	}
+
+	// try get an endpoint
+	ep, err := r.Endpoint(req)
+	if err != nil {
+		return nil, err
+	}
+
+	return ep, nil
+}
+
+func NewRouter(opts ...router.Option) *staticRouter {
+	options := router.NewOptions(opts...)
+	r := &staticRouter{
+		exit: make(chan bool),
+		opts: options,
+		eps:  make(map[string]*endpoint),
+	}
+	//go r.watch()
+	//go r.refresh()
+	return r
+}

api/service/proto/api.pb.go

@@ -0,0 +1,149 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// source: api.proto
+
+package go_micro_api
+
+import (
+	fmt "fmt"
+	proto "github.com/golang/protobuf/proto"
+	math "math"
+)
+
+// 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
+
+type Endpoint struct {
+	Name                 string   `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
+	Host                 []string `protobuf:"bytes,2,rep,name=host,proto3" json:"host,omitempty"`
+	Path                 []string `protobuf:"bytes,3,rep,name=path,proto3" json:"path,omitempty"`
+	Method               []string `protobuf:"bytes,4,rep,name=method,proto3" json:"method,omitempty"`
+	Stream               bool     `protobuf:"varint,5,opt,name=stream,proto3" json:"stream,omitempty"`
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *Endpoint) Reset()         { *m = Endpoint{} }
+func (m *Endpoint) String() string { return proto.CompactTextString(m) }
+func (*Endpoint) ProtoMessage()    {}
+func (*Endpoint) Descriptor() ([]byte, []int) {
+	return fileDescriptor_00212fb1f9d3bf1c, []int{0}
+}
+
+func (m *Endpoint) XXX_Unmarshal(b []byte) error {
+	return xxx_messageInfo_Endpoint.Unmarshal(m, b)
+}
+func (m *Endpoint) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	return xxx_messageInfo_Endpoint.Marshal(b, m, deterministic)
+}
+func (m *Endpoint) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Endpoint.Merge(m, src)
+}
+func (m *Endpoint) XXX_Size() int {
+	return xxx_messageInfo_Endpoint.Size(m)
+}
+func (m *Endpoint) XXX_DiscardUnknown() {
+	xxx_messageInfo_Endpoint.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_Endpoint proto.InternalMessageInfo
+
+func (m *Endpoint) GetName() string {
+	if m != nil {
+		return m.Name
+	}
+	return ""
+}
+
+func (m *Endpoint) GetHost() []string {
+	if m != nil {
+		return m.Host
+	}
+	return nil
+}
+
+func (m *Endpoint) GetPath() []string {
+	if m != nil {
+		return m.Path
+	}
+	return nil
+}
+
+func (m *Endpoint) GetMethod() []string {
+	if m != nil {
+		return m.Method
+	}
+	return nil
+}
+
+func (m *Endpoint) GetStream() bool {
+	if m != nil {
+		return m.Stream
+	}
+	return false
+}
+
+type EmptyResponse struct {
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *EmptyResponse) Reset()         { *m = EmptyResponse{} }
+func (m *EmptyResponse) String() string { return proto.CompactTextString(m) }
+func (*EmptyResponse) ProtoMessage()    {}
+func (*EmptyResponse) Descriptor() ([]byte, []int) {
+	return fileDescriptor_00212fb1f9d3bf1c, []int{1}
+}
+
+func (m *EmptyResponse) XXX_Unmarshal(b []byte) error {
+	return xxx_messageInfo_EmptyResponse.Unmarshal(m, b)
+}
+func (m *EmptyResponse) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	return xxx_messageInfo_EmptyResponse.Marshal(b, m, deterministic)
+}
+func (m *EmptyResponse) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_EmptyResponse.Merge(m, src)
+}
+func (m *EmptyResponse) XXX_Size() int {
+	return xxx_messageInfo_EmptyResponse.Size(m)
+}
+func (m *EmptyResponse) XXX_DiscardUnknown() {
+	xxx_messageInfo_EmptyResponse.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_EmptyResponse proto.InternalMessageInfo
+
+func init() {
+	proto.RegisterType((*Endpoint)(nil), "go.micro.api.Endpoint")
+	proto.RegisterType((*EmptyResponse)(nil), "go.micro.api.EmptyResponse")
+}
+
+func init() {
+	proto.RegisterFile("api.proto", fileDescriptor_00212fb1f9d3bf1c)
+}
+
+var fileDescriptor_00212fb1f9d3bf1c = []byte{
+	// 201 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xa4, 0xd0, 0x41, 0x4a, 0xc5, 0x30,
+	0x10, 0x06, 0x60, 0x63, 0x9f, 0x8f, 0xbe, 0x41, 0x11, 0xb2, 0x78, 0x04, 0xdd, 0x94, 0xae, 0xde,
+	0x2a, 0x0b, 0x3d, 0x41, 0xd1, 0x5e, 0x20, 0x37, 0x88, 0x76, 0x68, 0xb3, 0x48, 0x66, 0x48, 0x06,
+	0xc1, 0x43, 0x78, 0x67, 0x49, 0xad, 0x50, 0xdc, 0xba, 0xfb, 0xe7, 0x5b, 0xfc, 0xfc, 0x0c, 0x9c,
+	0x3c, 0x07, 0xcb, 0x99, 0x84, 0xf4, 0xed, 0x4c, 0x36, 0x86, 0xf7, 0x4c, 0xd6, 0x73, 0xe8, 0x3f,
+	0xa0, 0x1d, 0xd3, 0xc4, 0x14, 0x92, 0x68, 0x0d, 0x87, 0xe4, 0x23, 0x1a, 0xd5, 0xa9, 0xcb, 0xc9,
+	0xad, 0xb9, 0xda, 0x42, 0x45, 0xcc, 0x75, 0xd7, 0x54, 0xab, 0xb9, 0x1a, 0x7b, 0x59, 0x4c, 0xf3,
+	0x63, 0x35, 0xeb, 0x33, 0x1c, 0x23, 0xca, 0x42, 0x93, 0x39, 0xac, 0xba, 0x5d, 0xd5, 0x8b, 0x64,
+	0xf4, 0xd1, 0xdc, 0x74, 0xea, 0xd2, 0xba, 0xed, 0xea, 0xef, 0xe1, 0x6e, 0x8c, 0x2c, 0x9f, 0x0e,
+	0x0b, 0x53, 0x2a, 0xf8, 0xf4, 0xa5, 0xa0, 0x19, 0x38, 0xe8, 0x01, 0x5a, 0x87, 0x73, 0x28, 0x82,
+	0x59, 0x9f, 0xed, 0x7e, 0xab, 0xfd, 0x1d, 0xfa, 0xf0, 0xf8, 0xc7, 0xf7, 0x45, 0xfd, 0x95, 0x7e,
+	0x01, 0x78, 0xc5, 0xfc, 0xbf, 0x92, 0xb7, 0xe3, 0xfa, 0xad, 0xe7, 0xef, 0x00, 0x00, 0x00, 0xff,
+	0xff, 0x1f, 0xf0, 0xd9, 0x19, 0x3a, 0x01, 0x00, 0x00,
+}

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)
+}

api/service/proto/api.proto

@@ -0,0 +1,18 @@
+syntax = "proto3";
+
+package go.micro.api;
+
+service Api {
+  rpc Register(Endpoint) returns (EmptyResponse) {};
+  rpc Deregister(Endpoint) returns (EmptyResponse) {};
+}
+
+message Endpoint {
+  string name = 1;
+  repeated string host = 2;
+  repeated string path = 3;
+  repeated string method = 4;
+  bool stream = 5;
+}
+
+message EmptyResponse {}

go.mod

@@ -31,7 +31,7 @@ require (
 	github.com/gorilla/websocket v1.4.1
 	github.com/grpc-ecosystem/go-grpc-middleware v1.1.0 // indirect
 	github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0 // indirect
-	github.com/grpc-ecosystem/grpc-gateway v1.9.5 // indirect
+	github.com/grpc-ecosystem/grpc-gateway v1.9.5
 	github.com/hashicorp/hcl v1.0.0
 	github.com/imdario/mergo v0.3.8
 	github.com/jonboulle/clockwork v0.1.0 // indirect

metadata/metadata.go

@@ -6,7 +6,7 @@ import (
 	"strings"
 )
 
-type metaKey struct{}
+type MetadataKey struct{}
 
 // Metadata is our way of representing request headers internally.
 // They're used at the RPC level and translate back and forth
@@ -41,7 +41,7 @@ func Set(ctx context.Context, k, v string) context.Context {
 		md = make(Metadata)
 	}
 	md[k] = v
-	return context.WithValue(ctx, metaKey{}, md)
+	return context.WithValue(ctx, MetadataKey{}, md)
 }
 
 // Get returns a single value from metadata in the context
@@ -64,7 +64,7 @@ func Get(ctx context.Context, key string) (string, bool) {
 
 // FromContext returns metadata from the given context
 func FromContext(ctx context.Context) (Metadata, bool) {
-	md, ok := ctx.Value(metaKey{}).(Metadata)
+	md, ok := ctx.Value(MetadataKey{}).(Metadata)
 	if !ok {
 		return nil, ok
 	}
@@ -80,7 +80,7 @@ func FromContext(ctx context.Context) (Metadata, bool) {
 
 // NewContext creates a new context with the given metadata
 func NewContext(ctx context.Context, md Metadata) context.Context {
-	return context.WithValue(ctx, metaKey{}, md)
+	return context.WithValue(ctx, MetadataKey{}, md)
 }
 
 // MergeContext merges metadata to existing metadata, overwriting if specified
@@ -88,7 +88,7 @@ func MergeContext(ctx context.Context, patchMd Metadata, overwrite bool) context
 	if ctx == nil {
 		ctx = context.Background()
 	}
-	md, _ := ctx.Value(metaKey{}).(Metadata)
+	md, _ := ctx.Value(MetadataKey{}).(Metadata)
 	cmd := make(Metadata)
 	for k, v := range md {
 		cmd[k] = v
@@ -100,5 +100,5 @@ func MergeContext(ctx context.Context, patchMd Metadata, overwrite bool) context
 			cmd[k] = v
 		}
 	}
-	return context.WithValue(ctx, metaKey{}, cmd)
+	return context.WithValue(ctx, MetadataKey{}, cmd)
 }

server/grpc/codec.go

@@ -20,7 +20,11 @@ type bytesCodec struct{}
 type protoCodec struct{}
 type wrapCodec struct{ encoding.Codec }
 
-var jsonpbMarshaler = &jsonpb.Marshaler{}
+var jsonpbMarshaler = &jsonpb.Marshaler{
+	EnumsAsInts:  false,
+	EmitDefaults: false,
+	OrigName:     true,
+}
 
 var (
 	defaultGRPCCodecs = map[string]encoding.Codec{