chore: import upstream snapshot with attribution

server/grpc/codec.go

@@ -0,0 +1,182 @@
+package grpc
+
+import (
+	"encoding/json"
+	"strings"
+
+	"go-micro.dev/v6/codec"
+	"go-micro.dev/v6/codec/bytes"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/encoding"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/protobuf/encoding/protojson"
+	"google.golang.org/protobuf/proto"
+)
+
+type jsonCodec struct{}
+type bytesCodec struct{}
+type protoCodec struct{}
+type wrapCodec struct{ encoding.Codec }
+
+var protojsonMarshaler = protojson.MarshalOptions{
+	UseProtoNames:   true,
+	EmitUnpopulated: false,
+}
+
+var (
+	defaultGRPCCodecs = map[string]encoding.Codec{
+		"application/json":         jsonCodec{},
+		"application/proto":        protoCodec{},
+		"application/protobuf":     protoCodec{},
+		"application/octet-stream": protoCodec{},
+		"application/grpc":         protoCodec{},
+		"application/grpc+json":    jsonCodec{},
+		"application/grpc+proto":   protoCodec{},
+		"application/grpc+bytes":   bytesCodec{},
+	}
+)
+
+func (w wrapCodec) String() string {
+	return w.Name()
+}
+
+func (w wrapCodec) Marshal(v interface{}) ([]byte, error) {
+	b, ok := v.(*bytes.Frame)
+	if ok {
+		return b.Data, nil
+	}
+	return w.Codec.Marshal(v)
+}
+
+func (w wrapCodec) Unmarshal(data []byte, v interface{}) error {
+	b, ok := v.(*bytes.Frame)
+	if ok {
+		b.Data = data
+		return nil
+	}
+	if v == nil {
+		return nil
+	}
+	return w.Codec.Unmarshal(data, v)
+}
+
+func (protoCodec) Marshal(v interface{}) ([]byte, error) {
+	m, ok := v.(proto.Message)
+	if !ok {
+		return nil, codec.ErrInvalidMessage
+	}
+	return proto.Marshal(m)
+}
+
+func (protoCodec) Unmarshal(data []byte, v interface{}) error {
+	m, ok := v.(proto.Message)
+	if !ok {
+		return codec.ErrInvalidMessage
+	}
+	return proto.Unmarshal(data, m)
+}
+
+func (protoCodec) Name() string {
+	return "proto"
+}
+
+func (jsonCodec) Marshal(v interface{}) ([]byte, error) {
+	if pb, ok := v.(proto.Message); ok {
+		return protojsonMarshaler.Marshal(pb)
+	}
+
+	return json.Marshal(v)
+}
+
+func (jsonCodec) Unmarshal(data []byte, v interface{}) error {
+	if len(data) == 0 {
+		return nil
+	}
+	if pb, ok := v.(proto.Message); ok {
+		return protojson.Unmarshal(data, pb)
+	}
+	return json.Unmarshal(data, v)
+}
+
+func (jsonCodec) Name() string {
+	return "json"
+}
+
+func (bytesCodec) Marshal(v interface{}) ([]byte, error) {
+	b, ok := v.(*[]byte)
+	if !ok {
+		return nil, codec.ErrInvalidMessage
+	}
+	return *b, nil
+}
+
+func (bytesCodec) Unmarshal(data []byte, v interface{}) error {
+	b, ok := v.(*[]byte)
+	if !ok {
+		return codec.ErrInvalidMessage
+	}
+	*b = data
+	return nil
+}
+
+func (bytesCodec) Name() string {
+	return "bytes"
+}
+
+type grpcCodec struct {
+	// headers
+	id       string
+	target   string
+	method   string
+	endpoint string
+
+	s grpc.ServerStream
+	c encoding.Codec
+}
+
+func (g *grpcCodec) ReadHeader(m *codec.Message, mt codec.MessageType) error {
+	md, _ := metadata.FromIncomingContext(g.s.Context())
+	if m == nil {
+		m = new(codec.Message)
+	}
+	if m.Header == nil {
+		m.Header = make(map[string]string, len(md))
+	}
+	for k, v := range md {
+		m.Header[k] = strings.Join(v, ",")
+	}
+	m.Id = g.id
+	m.Target = g.target
+	m.Method = g.method
+	m.Endpoint = g.endpoint
+	return nil
+}
+
+func (g *grpcCodec) ReadBody(v interface{}) error {
+	// caller has requested a frame
+	if f, ok := v.(*bytes.Frame); ok {
+		return g.s.RecvMsg(f)
+	}
+	return g.s.RecvMsg(v)
+}
+
+func (g *grpcCodec) Write(m *codec.Message, v interface{}) error {
+	// if we don't have a body
+	if v != nil {
+		b, err := g.c.Marshal(v)
+		if err != nil {
+			return err
+		}
+		m.Body = b
+	}
+	// write the body using the framing codec
+	return g.s.SendMsg(&bytes.Frame{Data: m.Body})
+}
+
+func (g *grpcCodec) Close() error {
+	return nil
+}
+
+func (g *grpcCodec) String() string {
+	return "grpc"
+}

server/grpc/context.go

@@ -0,0 +1,16 @@
+package grpc
+
+import (
+	"context"
+
+	"go-micro.dev/v6/server"
+)
+
+func setServerOption(k, v interface{}) server.Option {
+	return func(o *server.Options) {
+		if o.Context == nil {
+			o.Context = context.Background()
+		}
+		o.Context = context.WithValue(o.Context, k, v)
+	}
+}

server/grpc/error.go

@@ -0,0 +1,42 @@
+package grpc
+
+import (
+	"net/http"
+
+	"go-micro.dev/v6/errors"
+	"google.golang.org/grpc/codes"
+)
+
+func microError(err *errors.Error) codes.Code {
+	switch err {
+	case nil:
+		return codes.OK
+	}
+
+	switch err.Code {
+	case http.StatusOK:
+		return codes.OK
+	case http.StatusBadRequest:
+		return codes.InvalidArgument
+	case http.StatusRequestTimeout:
+		return codes.DeadlineExceeded
+	case http.StatusNotFound:
+		return codes.NotFound
+	case http.StatusConflict:
+		return codes.AlreadyExists
+	case http.StatusForbidden:
+		return codes.PermissionDenied
+	case http.StatusUnauthorized:
+		return codes.Unauthenticated
+	case http.StatusPreconditionFailed:
+		return codes.FailedPrecondition
+	case http.StatusNotImplemented:
+		return codes.Unimplemented
+	case http.StatusInternalServerError:
+		return codes.Internal
+	case http.StatusServiceUnavailable:
+		return codes.Unavailable
+	}
+
+	return codes.Unknown
+}

server/grpc/extractor.go

@@ -0,0 +1,125 @@
+package grpc
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+
+	"go-micro.dev/v6/registry"
+)
+
+func extractValue(v reflect.Type, d int) *registry.Value {
+	if d == 3 {
+		return nil
+	}
+	if v == nil {
+		return nil
+	}
+
+	if v.Kind() == reflect.Pointer {
+		v = v.Elem()
+	}
+
+	arg := &registry.Value{
+		Name: v.Name(),
+		Type: v.Name(),
+	}
+
+	switch v.Kind() {
+	case reflect.Struct:
+		for i := 0; i < v.NumField(); i++ {
+			f := v.Field(i)
+			if f.PkgPath != "" {
+				continue
+			}
+			val := extractValue(f.Type, d+1)
+			if val == nil {
+				continue
+			}
+
+			// if we can find a json tag use it
+			if tags := f.Tag.Get("json"); len(tags) > 0 {
+				parts := strings.Split(tags, ",")
+				if parts[0] == "-" || parts[0] == "omitempty" {
+					continue
+				}
+				val.Name = parts[0]
+			}
+
+			// if there's no name default it
+			if len(val.Name) == 0 {
+				val.Name = v.Field(i).Name
+			}
+
+			arg.Values = append(arg.Values, val)
+		}
+	case reflect.Slice:
+		p := v.Elem()
+		if p.Kind() == reflect.Pointer {
+			p = p.Elem()
+		}
+		arg.Type = "[]" + p.Name()
+	}
+
+	return arg
+}
+
+func extractEndpoint(method reflect.Method) *registry.Endpoint {
+	if method.PkgPath != "" {
+		return nil
+	}
+
+	var rspType, reqType reflect.Type
+	var stream bool
+	mt := method.Type
+
+	switch mt.NumIn() {
+	case 3:
+		reqType = mt.In(1)
+		rspType = mt.In(2)
+	case 4:
+		reqType = mt.In(2)
+		rspType = mt.In(3)
+	default:
+		return nil
+	}
+
+	// are we dealing with a stream?
+	switch rspType.Kind() {
+	case reflect.Func, reflect.Interface:
+		stream = true
+	}
+
+	request := extractValue(reqType, 0)
+	response := extractValue(rspType, 0)
+
+	ep := &registry.Endpoint{
+		Name:     method.Name,
+		Request:  request,
+		Response: response,
+		Metadata: make(map[string]string),
+	}
+
+	if stream {
+		ep.Metadata = map[string]string{
+			"stream": fmt.Sprintf("%v", stream),
+		}
+	}
+
+	return ep
+}
+
+func extractSubValue(typ reflect.Type) *registry.Value {
+	var reqType reflect.Type
+	switch typ.NumIn() {
+	case 1:
+		reqType = typ.In(0)
+	case 2:
+		reqType = typ.In(1)
+	case 3:
+		reqType = typ.In(2)
+	default:
+		return nil
+	}
+	return extractValue(reqType, 0)
+}

server/grpc/extractor_test.go

@@ -0,0 +1,64 @@
+package grpc
+
+import (
+	"context"
+	"reflect"
+	"testing"
+
+	"go-micro.dev/v6/registry"
+)
+
+type testHandler struct{}
+
+type testRequest struct{}
+
+type testResponse struct{}
+
+func (t *testHandler) Test(ctx context.Context, req *testRequest, rsp *testResponse) error {
+	return nil
+}
+
+func TestExtractEndpoint(t *testing.T) {
+	handler := &testHandler{}
+	typ := reflect.TypeOf(handler)
+
+	var endpoints []*registry.Endpoint
+
+	for m := 0; m < typ.NumMethod(); m++ {
+		if e := extractEndpoint(typ.Method(m)); e != nil {
+			endpoints = append(endpoints, e)
+		}
+	}
+
+	if i := len(endpoints); i != 1 {
+		t.Errorf("Expected 1 endpoint, have %d", i)
+	}
+
+	if endpoints[0].Name != "Test" {
+		t.Errorf("Expected handler Test, got %s", endpoints[0].Name)
+	}
+
+	if endpoints[0].Request == nil {
+		t.Error("Expected non nil request")
+	}
+
+	if endpoints[0].Response == nil {
+		t.Error("Expected non nil request")
+	}
+
+	if endpoints[0].Request.Name != "testRequest" {
+		t.Errorf("Expected testRequest got %s", endpoints[0].Request.Name)
+	}
+
+	if endpoints[0].Response.Name != "testResponse" {
+		t.Errorf("Expected testResponse got %s", endpoints[0].Response.Name)
+	}
+
+	if endpoints[0].Request.Type != "testRequest" {
+		t.Errorf("Expected testRequest type got %s", endpoints[0].Request.Type)
+	}
+
+	if endpoints[0].Response.Type != "testResponse" {
+		t.Errorf("Expected testResponse type got %s", endpoints[0].Response.Type)
+	}
+}

server/grpc/graceful_stop_test.go

@@ -0,0 +1,146 @@
+package grpc
+
+import (
+	"context"
+	"net"
+	"testing"
+	"time"
+
+	micro "go-micro.dev/v6"
+	"go-micro.dev/v6/client"
+	grpcclient "go-micro.dev/v6/client/grpc"
+	"go-micro.dev/v6/registry"
+	"go-micro.dev/v6/server"
+)
+
+type SleepRequest struct {
+	DelayMS int `json:"delay_ms"`
+}
+
+type SleepResponse struct {
+	Message string `json:"message"`
+}
+
+type SleepHandler struct {
+	started chan struct{}
+}
+
+func (h *SleepHandler) Sleep(ctx context.Context, req *SleepRequest, rsp *SleepResponse) error {
+	select {
+	case h.started <- struct{}{}:
+	default:
+	}
+
+	timer := time.NewTimer(time.Duration(req.DelayMS) * time.Millisecond)
+	defer timer.Stop()
+
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	case <-timer.C:
+	}
+
+	rsp.Message = "ok"
+	return nil
+}
+
+func TestGracefulStopRejectsNewRPCsButAllowsInFlightRPCs(t *testing.T) {
+	listener, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("listen: %v", err)
+	}
+	defer listener.Close()
+
+	addr := listener.Addr().String()
+	reg := registry.NewMemoryRegistry()
+	handler := &SleepHandler{started: make(chan struct{}, 1)}
+
+	svc := micro.NewService("grace-demo",
+		micro.HandleSignal(false),
+		micro.Registry(reg),
+		micro.Server(NewServer(
+			server.Registry(reg),
+			server.Name("grace-demo"),
+			server.Address(addr),
+			Listener(listener),
+			GracefulStopTimeout(3*time.Second),
+		)),
+		micro.Client(grpcclient.NewClient(
+			client.Registry(reg),
+			client.ContentType("application/grpc+json"),
+			client.DialTimeout(200*time.Millisecond),
+			client.RequestTimeout(5*time.Second),
+		)),
+	)
+
+	if err := svc.Handle(handler); err != nil {
+		t.Fatalf("handle: %v", err)
+	}
+	if err := svc.Start(); err != nil {
+		t.Fatalf("start: %v", err)
+	}
+
+	stopped := false
+	defer func() {
+		if !stopped {
+			_ = svc.Stop()
+		}
+	}()
+
+	longDone := make(chan error, 1)
+	go func() {
+		req := svc.Client().NewRequest("grace-demo", "SleepHandler.Sleep", &SleepRequest{DelayMS: 1000})
+		rsp := &SleepResponse{}
+		longDone <- svc.Client().Call(context.Background(), req, rsp, client.WithAddress(addr))
+	}()
+
+	select {
+	case <-handler.started:
+	case <-time.After(2 * time.Second):
+		t.Fatal("timed out waiting for long RPC to start")
+	}
+
+	stopDone := make(chan error, 1)
+	go func() {
+		stopDone <- svc.Stop()
+	}()
+
+	freshReq := svc.Client().NewRequest("grace-demo", "SleepHandler.Sleep", &SleepRequest{DelayMS: 10})
+	freshRsp := &SleepResponse{}
+	var rejectErr error
+
+	deadline := time.Now().Add(300 * time.Millisecond)
+	for time.Now().Before(deadline) {
+		callCtx, cancel := context.WithTimeout(context.Background(), 150*time.Millisecond)
+		err := svc.Client().Call(callCtx, freshReq, freshRsp, client.WithAddress(addr))
+		cancel()
+		if err != nil {
+			rejectErr = err
+			break
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+
+	if rejectErr == nil {
+		t.Fatal("expected a new RPC to be rejected shortly after shutdown started")
+	}
+
+	select {
+	case err := <-longDone:
+		if err != nil {
+			t.Fatalf("long RPC failed during graceful stop: %v", err)
+		}
+	case <-time.After(2 * time.Second):
+		t.Fatal("timed out waiting for in-flight RPC to finish")
+	}
+
+	select {
+	case err := <-stopDone:
+		if err != nil {
+			t.Fatalf("stop: %v", err)
+		}
+		stopped = true
+	case <-time.After(2 * time.Second):
+		t.Fatal("timed out waiting for server stop")
+	}
+}

server/grpc/handler.go

@@ -0,0 +1,66 @@
+package grpc
+
+import (
+	"reflect"
+
+	"go-micro.dev/v6/registry"
+	"go-micro.dev/v6/server"
+)
+
+type rpcHandler struct {
+	name      string
+	handler   interface{}
+	endpoints []*registry.Endpoint
+	opts      server.HandlerOptions
+}
+
+func newRpcHandler(handler interface{}, opts ...server.HandlerOption) server.Handler {
+	options := server.HandlerOptions{
+		Metadata: make(map[string]map[string]string),
+	}
+
+	for _, o := range opts {
+		o(&options)
+	}
+
+	typ := reflect.TypeOf(handler)
+	hdlr := reflect.ValueOf(handler)
+	name := reflect.Indirect(hdlr).Type().Name()
+
+	var endpoints []*registry.Endpoint
+
+	for m := 0; m < typ.NumMethod(); m++ {
+		if e := extractEndpoint(typ.Method(m)); e != nil {
+			e.Name = name + "." + e.Name
+
+			for k, v := range options.Metadata[e.Name] {
+				e.Metadata[k] = v
+			}
+
+			endpoints = append(endpoints, e)
+		}
+	}
+
+	return &rpcHandler{
+		name:      name,
+		handler:   handler,
+		endpoints: endpoints,
+		opts:      options,
+	}
+}
+
+func (r *rpcHandler) Name() string {
+	return r.name
+}
+
+func (r *rpcHandler) Handler() interface{} {
+	return r.handler
+}
+
+func (r *rpcHandler) Endpoints() []*registry.Endpoint {
+	return r.endpoints
+}
+
+func (r *rpcHandler) Options() server.HandlerOptions {
+	return r.opts
+}

server/grpc/options.go

@@ -0,0 +1,102 @@
+package grpc
+
+import (
+	"context"
+	"crypto/tls"
+	"net"
+	"time"
+
+	"go-micro.dev/v6/broker"
+	"go-micro.dev/v6/codec"
+	"go-micro.dev/v6/logger"
+	"go-micro.dev/v6/registry"
+	"go-micro.dev/v6/server"
+	"go-micro.dev/v6/transport"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/encoding"
+)
+
+type codecsKey struct{}
+type grpcOptions struct{}
+type netListener struct{}
+type maxMsgSizeKey struct{}
+type maxConnKey struct{}
+type tlsAuth struct{}
+type grpcServerKey struct{}
+type gracefulStopTimeoutKey struct{}
+
+// gRPC Codec to be used to encode/decode requests for a given content type.
+func Codec(contentType string, c encoding.Codec) server.Option {
+	return func(o *server.Options) {
+		codecs := make(map[string]encoding.Codec)
+		if o.Context == nil {
+			o.Context = context.Background()
+		}
+		if v, ok := o.Context.Value(codecsKey{}).(map[string]encoding.Codec); ok && v != nil {
+			codecs = v
+		}
+		codecs[contentType] = c
+		o.Context = context.WithValue(o.Context, codecsKey{}, codecs)
+	}
+}
+
+// AuthTLS should be used to setup a secure authentication using TLS.
+func AuthTLS(t *tls.Config) server.Option {
+	return setServerOption(tlsAuth{}, t)
+}
+
+// MaxConn specifies maximum number of max simultaneous connections to server.
+func MaxConn(n int) server.Option {
+	return setServerOption(maxConnKey{}, n)
+}
+
+// Listener specifies the net.Listener to use instead of the default.
+func Listener(l net.Listener) server.Option {
+	return setServerOption(netListener{}, l)
+}
+
+// Server specifies a *grpc.Server to use instead of the default
+// This is for rare use case where user need to expose grpc.Server for
+// customization. Please NOTE however user injected grpcServer doesn't support
+// server Handler abstraction.
+func Server(srv *grpc.Server) server.Option {
+	return setServerOption(grpcServerKey{}, srv)
+}
+
+// Options to be used to configure gRPC options.
+func Options(opts ...grpc.ServerOption) server.Option {
+	return setServerOption(grpcOptions{}, opts)
+}
+
+// MaxMsgSize set the maximum message in bytes the server can receive and
+// send.  Default maximum message size is 4 MB.
+func MaxMsgSize(s int) server.Option {
+	return setServerOption(maxMsgSizeKey{}, s)
+}
+
+// GracefulStopTimeout sets how long Stop waits for active RPCs before forcing Stop.
+func GracefulStopTimeout(timeout time.Duration) server.Option {
+	return setServerOption(gracefulStopTimeoutKey{}, timeout)
+}
+
+func newOptions(opt ...server.Option) server.Options {
+	opts := server.Options{
+		Codecs:        make(map[string]codec.NewCodec),
+		Metadata:      map[string]string{},
+		Broker:        broker.DefaultBroker,
+		Registry:      registry.DefaultRegistry,
+		RegisterCheck: server.DefaultRegisterCheck,
+		Transport:     transport.DefaultTransport,
+		Address:       server.DefaultAddress,
+		Name:          server.DefaultName,
+		Id:            server.DefaultId,
+		Version:       server.DefaultVersion,
+		Logger:        logger.DefaultLogger,
+	}
+
+	for _, o := range opt {
+		o(&opts)
+	}
+
+	return opts
+}

server/grpc/request.go

@@ -0,0 +1,90 @@
+package grpc
+
+import (
+	"go-micro.dev/v6/codec"
+	"go-micro.dev/v6/codec/bytes"
+)
+
+type rpcRequest struct {
+	service     string
+	method      string
+	contentType string
+	codec       codec.Codec
+	header      map[string]string
+	body        []byte
+	stream      bool
+	payload     interface{}
+}
+
+type rpcMessage struct {
+	topic       string
+	contentType string
+	payload     interface{}
+	header      map[string]string
+	body        []byte
+	codec       codec.Codec
+}
+
+func (r *rpcRequest) ContentType() string {
+	return r.contentType
+}
+
+func (r *rpcRequest) Service() string {
+	return r.service
+}
+
+func (r *rpcRequest) Method() string {
+	return r.method
+}
+
+func (r *rpcRequest) Endpoint() string {
+	return r.method
+}
+
+func (r *rpcRequest) Codec() codec.Reader {
+	return r.codec
+}
+
+func (r *rpcRequest) Header() map[string]string {
+	return r.header
+}
+
+func (r *rpcRequest) Read() ([]byte, error) {
+	f := &bytes.Frame{}
+	if err := r.codec.ReadBody(f); err != nil {
+		return nil, err
+	}
+	return f.Data, nil
+}
+
+func (r *rpcRequest) Stream() bool {
+	return r.stream
+}
+
+func (r *rpcRequest) Body() interface{} {
+	return r.payload
+}
+
+func (r *rpcMessage) ContentType() string {
+	return r.contentType
+}
+
+func (r *rpcMessage) Topic() string {
+	return r.topic
+}
+
+func (r *rpcMessage) Payload() interface{} {
+	return r.payload
+}
+
+func (r *rpcMessage) Header() map[string]string {
+	return r.header
+}
+
+func (r *rpcMessage) Body() []byte {
+	return r.body
+}
+
+func (r *rpcMessage) Codec() codec.Reader {
+	return r.codec
+}

server/grpc/response.go

@@ -0,0 +1,27 @@
+package grpc
+
+import (
+	"go-micro.dev/v6/codec"
+)
+
+type rpcResponse struct {
+	header map[string]string
+	codec  codec.Codec
+}
+
+func (r *rpcResponse) Codec() codec.Writer {
+	return r.codec
+}
+
+func (r *rpcResponse) WriteHeader(hdr map[string]string) {
+	for k, v := range hdr {
+		r.header[k] = v
+	}
+}
+
+func (r *rpcResponse) Write(b []byte) error {
+	return r.codec.Write(&codec.Message{
+		Header: r.header,
+		Body:   b,
+	}, nil)
+}

server/grpc/server.go

@@ -0,0 +1,182 @@
+package grpc
+
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+//
+// Meh, we need to get rid of this shit
+
+import (
+	"context"
+	"errors"
+	"reflect"
+	"sync"
+	"unicode"
+	"unicode/utf8"
+
+	"go-micro.dev/v6/logger"
+	"go-micro.dev/v6/server"
+)
+
+var (
+	// Precompute the reflect type for error. Can't use error directly
+	// because Typeof takes an empty interface value. This is annoying.
+	typeOfError = reflect.TypeOf((*error)(nil)).Elem()
+)
+
+type methodType struct {
+	method      reflect.Method
+	ArgType     reflect.Type
+	ReplyType   reflect.Type
+	ContextType reflect.Type
+	stream      bool
+}
+
+type service struct {
+	name   string                 // name of service
+	rcvr   reflect.Value          // receiver of methods for the service
+	typ    reflect.Type           // type of the receiver
+	method map[string]*methodType // registered methods
+}
+
+// server represents an RPC Server.
+type rServer struct {
+	mu         sync.Mutex // protects the serviceMap
+	serviceMap map[string]*service
+	logger     logger.Logger
+}
+
+// Is this an exported - upper case - name?
+func isExported(name string) bool {
+	rune, _ := utf8.DecodeRuneInString(name)
+	return unicode.IsUpper(rune)
+}
+
+// Is this type exported or a builtin?
+func isExportedOrBuiltinType(t reflect.Type) bool {
+	for t.Kind() == reflect.Pointer {
+		t = t.Elem()
+	}
+	// PkgPath will be non-empty even for an exported type,
+	// so we need to check the type name as well.
+	return isExported(t.Name()) || t.PkgPath() == ""
+}
+
+// prepareEndpoint() returns a methodType for the provided method or nil
+// in case if the method was unsuitable.
+func prepareEndpoint(method reflect.Method, log logger.Logger) *methodType {
+	mtype := method.Type
+	mname := method.Name
+	var replyType, argType, contextType reflect.Type
+	var stream bool
+
+	// Endpoint() must be exported.
+	if method.PkgPath != "" {
+		return nil
+	}
+
+	switch mtype.NumIn() {
+	case 3:
+		// assuming streaming
+		argType = mtype.In(2)
+		contextType = mtype.In(1)
+		stream = true
+	case 4:
+		// method that takes a context
+		argType = mtype.In(2)
+		replyType = mtype.In(3)
+		contextType = mtype.In(1)
+	default:
+		log.Logf(logger.ErrorLevel, "method %v of %v has wrong number of ins: %v", mname, mtype, mtype.NumIn())
+		return nil
+	}
+
+	if stream {
+		// check stream type
+		streamType := reflect.TypeOf((*server.Stream)(nil)).Elem()
+		if !argType.Implements(streamType) {
+			log.Logf(logger.ErrorLevel, "%v argument does not implement Streamer interface: %v", mname, argType)
+			return nil
+		}
+	} else {
+		// if not stream check the replyType
+
+		// First arg need not be a pointer.
+		if !isExportedOrBuiltinType(argType) {
+			log.Logf(logger.ErrorLevel, "%v argument type not exported: %v", mname, argType)
+			return nil
+		}
+
+		if replyType.Kind() != reflect.Pointer {
+			log.Logf(logger.ErrorLevel, "method %v reply type not a pointer: %v", mname, replyType)
+			return nil
+		}
+
+		// Reply type must be exported.
+		if !isExportedOrBuiltinType(replyType) {
+			log.Logf(logger.ErrorLevel, "method %v reply type not exported: %v", mname, replyType)
+			return nil
+		}
+	}
+
+	// Endpoint() needs one out.
+	if mtype.NumOut() != 1 {
+		log.Logf(logger.ErrorLevel, "method %v has wrong number of outs: %v", mname, mtype.NumOut())
+		return nil
+	}
+	// The return type of the method must be error.
+	if returnType := mtype.Out(0); returnType != typeOfError {
+		log.Logf(logger.ErrorLevel, "method %v returns %v not error", mname, returnType.String())
+		return nil
+	}
+	return &methodType{method: method, ArgType: argType, ReplyType: replyType, ContextType: contextType, stream: stream}
+}
+
+func (server *rServer) register(rcvr interface{}) error {
+	server.mu.Lock()
+	defer server.mu.Unlock()
+	log := server.logger
+	if server.serviceMap == nil {
+		server.serviceMap = make(map[string]*service)
+	}
+	s := new(service)
+	s.typ = reflect.TypeOf(rcvr)
+	s.rcvr = reflect.ValueOf(rcvr)
+	sname := reflect.Indirect(s.rcvr).Type().Name()
+	if sname == "" {
+		logger.Fatalf("rpc: no service name for type %v", s.typ.String())
+	}
+	if !isExported(sname) {
+		s := "rpc Register: type " + sname + " is not exported"
+		log.Log(logger.ErrorLevel, s)
+		return errors.New(s)
+	}
+	if _, present := server.serviceMap[sname]; present {
+		return errors.New("rpc: service already defined: " + sname)
+	}
+	s.name = sname
+	s.method = make(map[string]*methodType)
+
+	// Install the methods
+	for m := 0; m < s.typ.NumMethod(); m++ {
+		method := s.typ.Method(m)
+		if mt := prepareEndpoint(method, log); mt != nil {
+			s.method[method.Name] = mt
+		}
+	}
+
+	if len(s.method) == 0 {
+		s := "rpc Register: type " + sname + " has no exported methods of suitable type"
+		log.Log(logger.ErrorLevel, s)
+		return errors.New(s)
+	}
+	server.serviceMap[s.name] = s
+	return nil
+}
+
+func (m *methodType) prepareContext(ctx context.Context) reflect.Value {
+	if contextv := reflect.ValueOf(ctx); contextv.IsValid() {
+		return contextv
+	}
+	return reflect.Zero(m.ContextType)
+}

server/grpc/stream.go

@@ -0,0 +1,38 @@
+package grpc
+
+import (
+	"context"
+
+	"go-micro.dev/v6/server"
+	"google.golang.org/grpc"
+)
+
+// rpcStream implements a server side Stream.
+type rpcStream struct {
+	s       grpc.ServerStream
+	request server.Request
+}
+
+func (r *rpcStream) Close() error {
+	return nil
+}
+
+func (r *rpcStream) Error() error {
+	return nil
+}
+
+func (r *rpcStream) Request() server.Request {
+	return r.request
+}
+
+func (r *rpcStream) Context() context.Context {
+	return r.s.Context()
+}
+
+func (r *rpcStream) Send(m interface{}) error {
+	return r.s.SendMsg(m)
+}
+
+func (r *rpcStream) Recv(m interface{}) error {
+	return r.s.RecvMsg(m)
+}

server/grpc/subscriber.go

@@ -0,0 +1,291 @@
+package grpc
+
+import (
+	"context"
+	"fmt"
+	"reflect"
+	"runtime/debug"
+	"strings"
+
+	"go-micro.dev/v6/broker"
+	"go-micro.dev/v6/errors"
+	"go-micro.dev/v6/logger"
+	"go-micro.dev/v6/metadata"
+	"go-micro.dev/v6/registry"
+	"go-micro.dev/v6/server"
+)
+
+const (
+	subSig = "func(context.Context, interface{}) error"
+)
+
+type handler struct {
+	method  reflect.Value
+	reqType reflect.Type
+	ctxType reflect.Type
+}
+
+type subscriber struct {
+	topic      string
+	rcvr       reflect.Value
+	typ        reflect.Type
+	subscriber interface{}
+	handlers   []*handler
+	endpoints  []*registry.Endpoint
+	opts       server.SubscriberOptions
+}
+
+func newSubscriber(topic string, sub interface{}, opts ...server.SubscriberOption) server.Subscriber {
+	options := server.SubscriberOptions{
+		AutoAck: true,
+	}
+
+	for _, o := range opts {
+		o(&options)
+	}
+
+	var endpoints []*registry.Endpoint
+	var handlers []*handler
+
+	if typ := reflect.TypeOf(sub); typ.Kind() == reflect.Func {
+		h := &handler{
+			method: reflect.ValueOf(sub),
+		}
+
+		switch typ.NumIn() {
+		case 1:
+			h.reqType = typ.In(0)
+		case 2:
+			h.ctxType = typ.In(0)
+			h.reqType = typ.In(1)
+		}
+
+		handlers = append(handlers, h)
+
+		endpoints = append(endpoints, &registry.Endpoint{
+			Name:    "Func",
+			Request: extractSubValue(typ),
+			Metadata: map[string]string{
+				"topic":      topic,
+				"subscriber": "true",
+			},
+		})
+	} else {
+		hdlr := reflect.ValueOf(sub)
+		name := reflect.Indirect(hdlr).Type().Name()
+
+		for m := 0; m < typ.NumMethod(); m++ {
+			method := typ.Method(m)
+			h := &handler{
+				method: method.Func,
+			}
+
+			switch method.Type.NumIn() {
+			case 2:
+				h.reqType = method.Type.In(1)
+			case 3:
+				h.ctxType = method.Type.In(1)
+				h.reqType = method.Type.In(2)
+			}
+
+			handlers = append(handlers, h)
+
+			endpoints = append(endpoints, &registry.Endpoint{
+				Name:    name + "." + method.Name,
+				Request: extractSubValue(method.Type),
+				Metadata: map[string]string{
+					"topic":      topic,
+					"subscriber": "true",
+				},
+			})
+		}
+	}
+
+	return &subscriber{
+		rcvr:       reflect.ValueOf(sub),
+		typ:        reflect.TypeOf(sub),
+		topic:      topic,
+		subscriber: sub,
+		handlers:   handlers,
+		endpoints:  endpoints,
+		opts:       options,
+	}
+}
+
+func validateSubscriber(sub server.Subscriber) error {
+	typ := reflect.TypeOf(sub.Subscriber())
+	var argType reflect.Type
+
+	if typ.Kind() == reflect.Func {
+		name := "Func"
+		switch typ.NumIn() {
+		case 2:
+			argType = typ.In(1)
+		default:
+			return fmt.Errorf("subscriber %v takes wrong number of args: %v required signature %s", name, typ.NumIn(), subSig)
+		}
+		if !isExportedOrBuiltinType(argType) {
+			return fmt.Errorf("subscriber %v argument type not exported: %v", name, argType)
+		}
+		if typ.NumOut() != 1 {
+			return fmt.Errorf("subscriber %v has wrong number of outs: %v require signature %s",
+				name, typ.NumOut(), subSig)
+		}
+		if returnType := typ.Out(0); returnType != typeOfError {
+			return fmt.Errorf("subscriber %v returns %v not error", name, returnType.String())
+		}
+	} else {
+		hdlr := reflect.ValueOf(sub.Subscriber())
+		name := reflect.Indirect(hdlr).Type().Name()
+
+		for m := 0; m < typ.NumMethod(); m++ {
+			method := typ.Method(m)
+
+			switch method.Type.NumIn() {
+			case 3:
+				argType = method.Type.In(2)
+			default:
+				return fmt.Errorf("subscriber %v.%v takes wrong number of args: %v required signature %s",
+					name, method.Name, method.Type.NumIn(), subSig)
+			}
+
+			if !isExportedOrBuiltinType(argType) {
+				return fmt.Errorf("%v argument type not exported: %v", name, argType)
+			}
+			if method.Type.NumOut() != 1 {
+				return fmt.Errorf(
+					"subscriber %v.%v has wrong number of outs: %v require signature %s",
+					name, method.Name, method.Type.NumOut(), subSig)
+			}
+			if returnType := method.Type.Out(0); returnType != typeOfError {
+				return fmt.Errorf("subscriber %v.%v returns %v not error", name, method.Name, returnType.String())
+			}
+		}
+	}
+
+	return nil
+}
+
+func (g *grpcServer) createSubHandler(sb *subscriber, opts server.Options) broker.Handler {
+	return func(p broker.Event) (err error) {
+		defer func() {
+			if r := recover(); r != nil {
+				g.opts.Logger.Log(logger.ErrorLevel, "panic recovered: ", r)
+				g.opts.Logger.Log(logger.ErrorLevel, string(debug.Stack()))
+				err = errors.InternalServerError("go.micro.server", "panic recovered: %v", r)
+			}
+		}()
+
+		msg := p.Message()
+		// if we don't have headers, create empty map
+		if msg.Header == nil {
+			msg.Header = make(map[string]string)
+		}
+
+		ct := msg.Header["Content-Type"]
+		if len(ct) == 0 {
+			msg.Header["Content-Type"] = defaultContentType
+			ct = defaultContentType
+		}
+		cf, err := g.newGRPCCodec(ct)
+		if err != nil {
+			return err
+		}
+
+		hdr := make(map[string]string, len(msg.Header))
+		for k, v := range msg.Header {
+			hdr[k] = v
+		}
+		delete(hdr, "Content-Type")
+		ctx := metadata.NewContext(context.Background(), hdr)
+
+		results := make(chan error, len(sb.handlers))
+
+		for i := 0; i < len(sb.handlers); i++ {
+			handler := sb.handlers[i]
+
+			var isVal bool
+			var req reflect.Value
+
+			if handler.reqType.Kind() == reflect.Pointer {
+				req = reflect.New(handler.reqType.Elem())
+			} else {
+				req = reflect.New(handler.reqType)
+				isVal = true
+			}
+			if isVal {
+				req = req.Elem()
+			}
+
+			if err = cf.Unmarshal(msg.Body, req.Interface()); err != nil {
+				return err
+			}
+
+			fn := func(ctx context.Context, msg server.Message) error {
+				var vals []reflect.Value
+				if sb.typ.Kind() != reflect.Func {
+					vals = append(vals, sb.rcvr)
+				}
+				if handler.ctxType != nil {
+					vals = append(vals, reflect.ValueOf(ctx))
+				}
+
+				vals = append(vals, reflect.ValueOf(msg.Payload()))
+
+				returnValues := handler.method.Call(vals)
+				if rerr := returnValues[0].Interface(); rerr != nil {
+					return rerr.(error)
+				}
+				return nil
+			}
+
+			for i := len(opts.SubWrappers); i > 0; i-- {
+				fn = opts.SubWrappers[i-1](fn)
+			}
+
+			if g.wg != nil {
+				g.wg.Add(1)
+			}
+			go func() {
+				if g.wg != nil {
+					defer g.wg.Done()
+				}
+				err := fn(ctx, &rpcMessage{
+					topic:       sb.topic,
+					contentType: ct,
+					payload:     req.Interface(),
+					header:      msg.Header,
+					body:        msg.Body,
+				})
+				results <- err
+			}()
+		}
+		var errors []string
+		for i := 0; i < len(sb.handlers); i++ {
+			if rerr := <-results; rerr != nil {
+				errors = append(errors, rerr.Error())
+			}
+		}
+		if len(errors) > 0 {
+			err = fmt.Errorf("subscriber error: %s", strings.Join(errors, "\n"))
+		}
+
+		return err
+	}
+}
+
+func (s *subscriber) Topic() string {
+	return s.topic
+}
+
+func (s *subscriber) Subscriber() interface{} {
+	return s.subscriber
+}
+
+func (s *subscriber) Endpoints() []*registry.Endpoint {
+	return s.endpoints
+}
+
+func (s *subscriber) Options() server.SubscriberOptions {
+	return s.opts
+}

server/grpc/util.go

@@ -0,0 +1,49 @@
+package grpc
+
+import (
+	"context"
+	"io"
+	"os"
+	"sync"
+
+	"google.golang.org/grpc/codes"
+)
+
+// convertCode converts a standard Go error into its canonical code. Note that
+// this is only used to translate the error returned by the server applications.
+func convertCode(err error) codes.Code {
+	switch err {
+	case nil:
+		return codes.OK
+	case io.EOF:
+		return codes.OutOfRange
+	case io.ErrClosedPipe, io.ErrNoProgress, io.ErrShortBuffer, io.ErrShortWrite, io.ErrUnexpectedEOF:
+		return codes.FailedPrecondition
+	case os.ErrInvalid:
+		return codes.InvalidArgument
+	case context.Canceled:
+		return codes.Canceled
+	case context.DeadlineExceeded:
+		return codes.DeadlineExceeded
+	}
+	switch {
+	case os.IsExist(err):
+		return codes.AlreadyExists
+	case os.IsNotExist(err):
+		return codes.NotFound
+	case os.IsPermission(err):
+		return codes.PermissionDenied
+	}
+	return codes.Unknown
+}
+
+func wait(ctx context.Context) *sync.WaitGroup {
+	if ctx == nil {
+		return nil
+	}
+	wg, ok := ctx.Value("wait").(*sync.WaitGroup)
+	if !ok {
+		return nil
+	}
+	return wg
+}