grpc request

Rename method to endpoint

README.md

@@ -1,8 +1,15 @@
 # Go Micro [![License](https://img.shields.io/:license-apache-blue.svg)](https://opensource.org/licenses/Apache-2.0) [![GoDoc](https://godoc.org/github.com/micro/go-micro?status.svg)](https://godoc.org/github.com/micro/go-micro) [![Travis CI](https://api.travis-ci.org/micro/go-micro.svg?branch=master)](https://travis-ci.org/micro/go-micro) [![Go Report Card](https://goreportcard.com/badge/micro/go-micro)](https://goreportcard.com/report/github.com/micro/go-micro)
 
-Go Micro is a pluggable framework for microservice development.
+Go Micro is a pluggable framework for micro service development.
+
+## Overview
+
+Go Micro provides the core requirements for distributed systems development including RPC and Event driven communication. 
+The **micro** philosophy is sane defaults with a pluggable architecture. We provide defaults to get you started quickly 
+but everything can be easily swapped out. 
+
+<img src="https://micro.mu/docs/images/go-micro.png" />
 
-The **micro** philosophy is sane defaults with a pluggable architecture. We provide defaults to get you started quickly but everything can be swapped out. 
 Plugins are available at [github.com/micro/go-plugins](https://github.com/micro/go-plugins).
 
 Follow us on [Twitter](https://twitter.com/microhq) or join the [Slack](http://slack.micro.mu/) community.
@@ -11,15 +18,33 @@ Follow us on [Twitter](https://twitter.com/microhq) or join the [Slack](http://s
 
 Go Micro abstracts away the details of distributed systems. Here are the main features.
 
-- **Service Discovery** - Automatic service registration and name resolution
-- **Load Balancing** - Client side load balancing built on discovery
-- **Message Encoding** - Dynamic encoding based on content-type with protobuf and json support
-- **Sync Streaming** - RPC based request/response with support for bidirectional streaming
-- **Async Messaging** - Native pubsub messaging built in for event driven architectures
+- **Service Discovery** - Automatic service registration and name resolution. Service discovery is at the core of micro service 
+development. When service A needs to speak to service B it needs the location of that service. Consul is the default discovery 
+system with multicast DNS (mdns) as a local option or the SWIM protocol (gossip) for zero dependency p2p networks.
+
+- **Load Balancing** - Client side load balancing built on service discovery. Once we have the addresses of any number of instances 
+of a service we now need a way to decide which node to route to. We use random hashed load balancing to provide even distribution 
+across the services and retry a different node if there's a problem. 
+
+- **Message Encoding** - Dynamic message encoding based on content-type. The client and server will use codecs along with content-type 
+to seamlessly encode and decode Go types for you. Any variety of messages could be encoded and sent from different clients. The client 
+and server handle this by default. This includes protobuf and json by default.
+
+- **Sync Streaming** - RPC based request/response with support for bidirectional streaming. We provide an abstraction for synchronous 
+communication. A request made to a service will be automatically resolved, load balanced, dialled and streamed. The default 
+transport is http/1.1 or http2 when tls is enabled.
+
+- **Async Messaging** - PubSub is built in as a first class citizen for asynchronous communication and event driven architectures. 
+Event notifications are a core pattern in micro service development. The default messaging is point-to-point http/1.1 or http2 when tls 
+is enabled.
+
+- **Pluggable Interfaces** - Go Micro makes use of Go interfaces for each distributed system abstraction. Because of this these interfaces 
+are pluggable and allows Go Micro to be runtime agnostic. You can plugin any underlying technology. Find plugins in 
+[github.com/micro/go-plugins](https://github.com/micro/go-plugins).
 
 ## Getting Started
 
-For detailed information on the architecture, installation and use of go-micro checkout the [docs](https://micro.mu/docs/go-micro.html).
+See the [docs](https://micro.mu/docs/go-micro.html) for detailed information on the architecture, installation and use of go-micro.
 
 ## Sponsors
 

broker/codec/codec.go

@@ -1,10 +0,0 @@
-package codec
-
-// Codec is used for encoding where the broker doesn't natively support
-// headers in the message type. In this case the entire message is
-// encoded as the payload
-type Codec interface {
-	Marshal(interface{}) ([]byte, error)
-	Unmarshal([]byte, interface{}) error
-	String() string
-}

broker/codec/json/json.go

@@ -1,25 +0,0 @@
-package json
-
-import (
-	"encoding/json"
-
-	"github.com/micro/go-micro/broker/codec"
-)
-
-type jsonCodec struct{}
-
-func (j jsonCodec) Marshal(v interface{}) ([]byte, error) {
-	return json.Marshal(v)
-}
-
-func (j jsonCodec) Unmarshal(d []byte, v interface{}) error {
-	return json.Unmarshal(d, v)
-}
-
-func (j jsonCodec) String() string {
-	return "json"
-}
-
-func NewCodec() codec.Codec {
-	return jsonCodec{}
-}

broker/codec/noop/noop.go

@@ -1,35 +0,0 @@
-package noop
-
-import (
-	"errors"
-
-	"github.com/micro/go-micro/broker"
-	"github.com/micro/go-micro/broker/codec"
-)
-
-type noopCodec struct{}
-
-func (n noopCodec) Marshal(v interface{}) ([]byte, error) {
-	msg, ok := v.(*broker.Message)
-	if !ok {
-		return nil, errors.New("invalid message")
-	}
-	return msg.Body, nil
-}
-
-func (n noopCodec) Unmarshal(d []byte, v interface{}) error {
-	msg, ok := v.(*broker.Message)
-	if !ok {
-		return errors.New("invalid message")
-	}
-	msg.Body = d
-	return nil
-}
-
-func (n noopCodec) String() string {
-	return "noop"
-}
-
-func NewCodec() codec.Codec {
-	return noopCodec{}
-}

broker/http_broker.go

@@ -20,13 +20,14 @@ import (
 
 	"github.com/google/uuid"
 	"github.com/micro/go-log"
-	"github.com/micro/go-micro/broker/codec/json"
+	"github.com/micro/go-micro/codec/json"
 	merr "github.com/micro/go-micro/errors"
 	"github.com/micro/go-micro/registry"
 	"github.com/micro/go-rcache"
 	maddr "github.com/micro/util/go/lib/addr"
 	mnet "github.com/micro/util/go/lib/net"
 	mls "github.com/micro/util/go/lib/tls"
+	"golang.org/x/net/http2"
 )
 
 // HTTP Broker is a point to point async broker
@@ -44,6 +45,10 @@ type httpBroker struct {
 	subscribers map[string][]*httpSubscriber
 	running     bool
 	exit        chan chan error
+
+	// offline message inbox
+	mtx   sync.RWMutex
+	inbox map[string][][]byte
 }
 
 type httpSubscriber struct {
@@ -78,6 +83,10 @@ func newTransport(config *tls.Config) *http.Transport {
 		}
 	}
 
+	dialTLS := func(network string, addr string) (net.Conn, error) {
+		return tls.Dial(network, addr, config)
+	}
+
 	t := &http.Transport{
 		Proxy: http.ProxyFromEnvironment,
 		Dial: (&net.Dialer{
@@ -85,17 +94,21 @@ func newTransport(config *tls.Config) *http.Transport {
 			KeepAlive: 30 * time.Second,
 		}).Dial,
 		TLSHandshakeTimeout: 10 * time.Second,
-		TLSClientConfig:     config,
+		DialTLS:             dialTLS,
 	}
 	runtime.SetFinalizer(&t, func(tr **http.Transport) {
 		(*tr).CloseIdleConnections()
 	})
+
+	// setup http2
+	http2.ConfigureTransport(t)
+
 	return t
 }
 
 func newHttpBroker(opts ...Option) Broker {
 	options := Options{
-		Codec:   json.NewCodec(),
+		Codec:   json.Marshaler{},
 		Context: context.TODO(),
 	}
 
@@ -124,6 +137,7 @@ func newHttpBroker(opts ...Option) Broker {
 		subscribers: make(map[string][]*httpSubscriber),
 		exit:        make(chan chan error),
 		mux:         http.NewServeMux(),
+		inbox:       make(map[string][][]byte),
 	}
 
 	// specify the message handler
@@ -166,6 +180,49 @@ func (h *httpSubscriber) Unsubscribe() error {
 	return h.hb.unsubscribe(h)
 }
 
+func (h *httpBroker) saveMessage(topic string, msg []byte) {
+	h.mtx.Lock()
+	defer h.mtx.Unlock()
+
+	// get messages
+	c := h.inbox[topic]
+
+	// save message
+	c = append(c, msg)
+
+	// max length 64
+	if len(c) > 64 {
+		c = c[:64]
+	}
+
+	// save inbox
+	h.inbox[topic] = c
+}
+
+func (h *httpBroker) getMessage(topic string, num int) [][]byte {
+	h.mtx.Lock()
+	defer h.mtx.Unlock()
+
+	// get messages
+	c, ok := h.inbox[topic]
+	if !ok {
+		return nil
+	}
+
+	// more message than requests
+	if len(c) >= num {
+		msg := c[:num]
+		h.inbox[topic] = c[num:]
+		return msg
+	}
+
+	// reset inbox
+	h.inbox[topic] = nil
+
+	// return all messages
+	return c
+}
+
 func (h *httpBroker) subscribe(s *httpSubscriber) error {
 	h.Lock()
 	defer h.Unlock()
@@ -430,6 +487,13 @@ func (h *httpBroker) Init(opts ...Option) error {
 	// set registry
 	h.r = rcache.New(reg)
 
+	// reconfigure tls config
+	if c := h.opts.TLSConfig; c != nil {
+		h.c = &http.Client{
+			Transport: newTransport(c),
+		}
+	}
+
 	return nil
 }
 
@@ -438,14 +502,7 @@ func (h *httpBroker) Options() Options {
 }
 
 func (h *httpBroker) Publish(topic string, msg *Message, opts ...PublishOption) error {
-	h.RLock()
-	s, err := h.r.GetService("topic:" + topic)
-	if err != nil {
-		h.RUnlock()
-		return err
-	}
-	h.RUnlock()
-
+	// create the message first
 	m := &Message{
 		Header: make(map[string]string),
 		Body:   msg.Body,
@@ -457,12 +514,26 @@ func (h *httpBroker) Publish(topic string, msg *Message, opts ...PublishOption)
 
 	m.Header[":topic"] = topic
 
+	// encode the message
 	b, err := h.opts.Codec.Marshal(m)
 	if err != nil {
 		return err
 	}
 
-	pub := func(node *registry.Node, b []byte) {
+	// save the message
+	h.saveMessage(topic, b)
+
+	// now attempt to get the service
+	h.RLock()
+	s, err := h.r.GetService("topic:" + topic)
+	if err != nil {
+		h.RUnlock()
+		// ignore error
+		return nil
+	}
+	h.RUnlock()
+
+	pub := func(node *registry.Node, t string, b []byte) error {
 		scheme := "http"
 
 		// check if secure is added in metadata
@@ -475,39 +546,76 @@ func (h *httpBroker) Publish(topic string, msg *Message, opts ...PublishOption)
 
 		uri := fmt.Sprintf("%s://%s:%d%s?%s", scheme, node.Address, node.Port, DefaultSubPath, vals.Encode())
 		r, err := h.c.Post(uri, "application/json", bytes.NewReader(b))
-		if err == nil {
-			io.Copy(ioutil.Discard, r.Body)
-			r.Body.Close()
+		if err != nil {
+			return err
 		}
+
+		// discard response body
+		io.Copy(ioutil.Discard, r.Body)
+		r.Body.Close()
+		return nil
 	}
 
-	for _, service := range s {
-		// only process if we have nodes
-		if len(service.Nodes) == 0 {
-			continue
-		}
-
-		switch service.Version {
-		// broadcast version means broadcast to all nodes
-		case broadcastVersion:
-			for _, node := range service.Nodes {
-				// publish async
-				go pub(node, b)
+	srv := func(s []*registry.Service, b []byte) {
+		for _, service := range s {
+			// only process if we have nodes
+			if len(service.Nodes) == 0 {
+				continue
 			}
-		default:
-			// select node to publish to
-			node := service.Nodes[rand.Int()%len(service.Nodes)]
 
-			// publish async
-			go pub(node, b)
+			switch service.Version {
+			// broadcast version means broadcast to all nodes
+			case broadcastVersion:
+				var success bool
+
+				// publish to all nodes
+				for _, node := range service.Nodes {
+					// publish async
+					if err := pub(node, topic, b); err == nil {
+						success = true
+					}
+				}
+
+				// save if it failed to publish at least once
+				if !success {
+					h.saveMessage(topic, b)
+				}
+			default:
+				// select node to publish to
+				node := service.Nodes[rand.Int()%len(service.Nodes)]
+
+				// publish async to one node
+				if err := pub(node, topic, b); err != nil {
+					// if failed save it
+					h.saveMessage(topic, b)
+				}
+			}
 		}
 	}
 
+	// do the rest async
+	go func() {
+		// get a third of the backlog
+		messages := h.getMessage(topic, 8)
+		delay := (len(messages) > 1)
+
+		// publish all the messages
+		for _, msg := range messages {
+			// serialize here
+			srv(s, msg)
+
+			// sending a backlog of messages
+			if delay {
+				time.Sleep(time.Millisecond * 100)
+			}
+		}
+	}()
+
 	return nil
 }
 
 func (h *httpBroker) Subscribe(topic string, handler Handler, opts ...SubscribeOption) (Subscriber, error) {
-	options := newSubscribeOptions(opts...)
+	options := NewSubscribeOptions(opts...)
 
 	// parse address for host, port
 	parts := strings.Split(h.Address(), ":")

broker/mock/mock.go

@@ -1,3 +1,4 @@
+// Package mock provides a mock broker for testing
 package mock
 
 import (

broker/options.go

@@ -4,14 +4,14 @@ import (
 	"context"
 	"crypto/tls"
 
-	"github.com/micro/go-micro/broker/codec"
+	"github.com/micro/go-micro/codec"
 	"github.com/micro/go-micro/registry"
 )
 
 type Options struct {
 	Addrs     []string
 	Secure    bool
-	Codec     codec.Codec
+	Codec     codec.Marshaler
 	TLSConfig *tls.Config
 	// Other options for implementations of the interface
 	// can be stored in a context
@@ -50,7 +50,7 @@ var (
 	registryKey = contextKeyT("github.com/micro/go-micro/registry")
 )
 
-func newSubscribeOptions(opts ...SubscribeOption) SubscribeOptions {
+func NewSubscribeOptions(opts ...SubscribeOption) SubscribeOptions {
 	opt := SubscribeOptions{
 		AutoAck: true,
 	}
@@ -71,7 +71,7 @@ func Addrs(addrs ...string) Option {
 
 // Codec sets the codec used for encoding/decoding used where
 // a broker does not support headers
-func Codec(c codec.Codec) Option {
+func Codec(c codec.Marshaler) Option {
 	return func(o *Options) {
 		o.Codec = c
 	}

client/client.go

@@ -4,6 +4,8 @@ package client
 import (
 	"context"
 	"time"
+
+	"github.com/micro/go-micro/codec"
 )
 
 // Client is the interface used to make requests to services.
@@ -13,13 +15,18 @@ type Client interface {
 	Init(...Option) error
 	Options() Options
 	NewMessage(topic string, msg interface{}, opts ...MessageOption) Message
-	NewRequest(service, method string, req interface{}, reqOpts ...RequestOption) Request
+	NewRequest(service, endpoint string, req interface{}, reqOpts ...RequestOption) Request
 	Call(ctx context.Context, req Request, rsp interface{}, opts ...CallOption) error
 	Stream(ctx context.Context, req Request, opts ...CallOption) (Stream, error)
 	Publish(ctx context.Context, msg Message, opts ...PublishOption) error
 	String() string
 }
 
+// Router manages request routing
+type Router interface {
+	SendRequest(context.Context, Request) (Response, error)
+}
+
 // Message is the interface for publishing asynchronously
 type Message interface {
 	Topic() string
@@ -29,14 +36,30 @@ type Message interface {
 
 // Request is the interface for a synchronous request used by Call or Stream
 type Request interface {
+	// The service to call
 	Service() string
-	Method() string
+	// The endpoint to call
+	Endpoint() string
+	// The content type
 	ContentType() string
-	Request() interface{}
+	// The unencoded request body
+	Body() interface{}
+	// Write to the encoded request writer. This is nil before a call is made
+	Codec() codec.Writer
 	// indicates whether the request will be a streaming one rather than unary
 	Stream() bool
 }
 
+// Response is the response received from a service
+type Response interface {
+	// Read the response
+	Codec() codec.Reader
+	// read the header
+	Header() map[string]string
+	// Read the undecoded response
+	Read() ([]byte, error)
+}
+
 // Stream is the inteface for a bidirectional synchronous stream
 type Stream interface {
 	Context() context.Context
@@ -102,8 +125,8 @@ func NewClient(opt ...Option) Client {
 
 // Creates a new request using the default client. Content Type will
 // be set to the default within options and use the appropriate codec
-func NewRequest(service, method string, request interface{}, reqOpts ...RequestOption) Request {
-	return DefaultClient.NewRequest(service, method, request, reqOpts...)
+func NewRequest(service, endpoint string, request interface{}, reqOpts ...RequestOption) Request {
+	return DefaultClient.NewRequest(service, endpoint, request, reqOpts...)
 }
 
 // Creates a streaming connection with a service and returns responses on the

client/mock/mock.go

@@ -1,3 +1,4 @@
+// Package mock provides a mock client for testing
 package mock
 
 import (
@@ -15,7 +16,7 @@ var (
 )
 
 type MockResponse struct {
-	Method   string
+	Endpoint string
 	Response interface{}
 	Error    error
 }
@@ -53,8 +54,8 @@ func (m *MockClient) NewMessage(topic string, msg interface{}, opts ...client.Me
 	return m.Client.NewMessage(topic, msg, opts...)
 }
 
-func (m *MockClient) NewRequest(service, method string, req interface{}, reqOpts ...client.RequestOption) client.Request {
-	return m.Client.NewRequest(service, method, req, reqOpts...)
+func (m *MockClient) NewRequest(service, endpoint string, req interface{}, reqOpts ...client.RequestOption) client.Request {
+	return m.Client.NewRequest(service, endpoint, req, reqOpts...)
 }
 
 func (m *MockClient) Call(ctx context.Context, req client.Request, rsp interface{}, opts ...client.CallOption) error {
@@ -67,7 +68,7 @@ func (m *MockClient) Call(ctx context.Context, req client.Request, rsp interface
 	}
 
 	for _, r := range response {
-		if r.Method != req.Method() {
+		if r.Endpoint != req.Endpoint() {
 			continue
 		}
 
@@ -90,7 +91,7 @@ func (m *MockClient) Call(ctx context.Context, req client.Request, rsp interface
 		return nil
 	}
 
-	return fmt.Errorf("rpc: can't find service %s", req.Method())
+	return fmt.Errorf("rpc: can't find service %s", req.Endpoint())
 }
 
 func (m *MockClient) Stream(ctx context.Context, req client.Request, opts ...client.CallOption) (client.Stream, error) {

client/mock/mock_test.go

@@ -13,17 +13,17 @@ func TestClient(t *testing.T) {
 	}
 
 	response := []MockResponse{
-		{Method: "Foo.Bar", Response: map[string]interface{}{"foo": "bar"}},
-		{Method: "Foo.Struct", Response: &TestResponse{Param: "aparam"}},
-		{Method: "Foo.Fail", Error: errors.InternalServerError("go.mock", "failed")},
-		{Method: "Foo.Func", Response: func() string { return "string" }},
-		{Method: "Foo.FuncStruct", Response: func() *TestResponse { return &TestResponse{Param: "aparam"} }},
+		{Endpoint: "Foo.Bar", Response: map[string]interface{}{"foo": "bar"}},
+		{Endpoint: "Foo.Struct", Response: &TestResponse{Param: "aparam"}},
+		{Endpoint: "Foo.Fail", Error: errors.InternalServerError("go.mock", "failed")},
+		{Endpoint: "Foo.Func", Response: func() string { return "string" }},
+		{Endpoint: "Foo.FuncStruct", Response: func() *TestResponse { return &TestResponse{Param: "aparam"} }},
 	}
 
 	c := NewClient(Response("go.mock", response))
 
 	for _, r := range response {
-		req := c.NewRequest("go.mock", r.Method, map[string]interface{}{"foo": "bar"})
+		req := c.NewRequest("go.mock", r.Endpoint, map[string]interface{}{"foo": "bar"})
 		var rsp interface{}
 
 		err := c.Call(context.TODO(), req, &rsp)

client/options.go

@@ -22,6 +22,9 @@ type Options struct {
 	Selector  selector.Selector
 	Transport transport.Transport
 
+	// Router sets the router
+	Router Router
+
 	// Connection Pool
 	PoolSize int
 	PoolTTL  time.Duration
@@ -99,7 +102,7 @@ func newOptions(options ...Option) Options {
 	}
 
 	if len(opts.ContentType) == 0 {
-		opts.ContentType = defaultContentType
+		opts.ContentType = DefaultContentType
 	}
 
 	if opts.Broker == nil {
@@ -306,3 +309,10 @@ func StreamingRequest() RequestOption {
 		o.Stream = true
 	}
 }
+
+// WithRouter sets the client router
+func WithRouter(r Router) Option {
+	return func(o *Options) {
+		o.Router = r
+	}
+}

client/rpc_client.go

@@ -9,6 +9,7 @@ import (
 
 	"sync/atomic"
 
+	"github.com/google/uuid"
 	"github.com/micro/go-micro/broker"
 	"github.com/micro/go-micro/codec"
 	"github.com/micro/go-micro/errors"
@@ -49,7 +50,7 @@ func (r *rpcClient) newCodec(contentType string) (codec.NewCodec, error) {
 	if c, ok := r.opts.Codecs[contentType]; ok {
 		return c, nil
 	}
-	if cf, ok := defaultCodecs[contentType]; ok {
+	if cf, ok := DefaultCodecs[contentType]; ok {
 		return cf, nil
 	}
 	return nil, fmt.Errorf("Unsupported Content-Type: %s", contentType)
@@ -96,8 +97,8 @@ func (r *rpcClient) call(ctx context.Context, address string, req Request, resp
 		context: ctx,
 		request: req,
 		closed:  make(chan bool),
-		codec:   newRpcPlusCodec(msg, c, cf),
-		seq:     seq,
+		codec:   newRpcCodec(msg, c, cf),
+		id:      fmt.Sprintf("%v", seq),
 	}
 	defer stream.Close()
 
@@ -111,7 +112,7 @@ func (r *rpcClient) call(ctx context.Context, address string, req Request, resp
 		}()
 
 		// send request
-		if err := stream.Send(req.Request()); err != nil {
+		if err := stream.Send(req.Body()); err != nil {
 			ch <- err
 			return
 		}
@@ -132,7 +133,7 @@ func (r *rpcClient) call(ctx context.Context, address string, req Request, resp
 		return err
 	case <-ctx.Done():
 		grr = ctx.Err()
-		return errors.New("go.micro.client", fmt.Sprintf("request timeout: %v", ctx.Err()), 408)
+		return errors.Timeout("go.micro.client", fmt.Sprintf("%v", ctx.Err()))
 	}
 }
 
@@ -177,13 +178,13 @@ func (r *rpcClient) stream(ctx context.Context, address string, req Request, opt
 		context: ctx,
 		request: req,
 		closed:  make(chan bool),
-		codec:   newRpcPlusCodec(msg, c, cf),
+		codec:   newRpcCodec(msg, c, cf),
 	}
 
 	ch := make(chan error, 1)
 
 	go func() {
-		ch <- stream.Send(req.Request())
+		ch <- stream.Send(req.Body())
 	}()
 
 	var grr error
@@ -192,7 +193,7 @@ func (r *rpcClient) stream(ctx context.Context, address string, req Request, opt
 	case err := <-ch:
 		grr = err
 	case <-ctx.Done():
-		grr = errors.New("go.micro.client", fmt.Sprintf("request timeout: %v", ctx.Err()), 408)
+		grr = errors.Timeout("go.micro.client", fmt.Sprintf("%v", ctx.Err()))
 	}
 
 	if grr != nil {
@@ -274,7 +275,7 @@ func (r *rpcClient) Call(ctx context.Context, request Request, response interfac
 	// should we noop right here?
 	select {
 	case <-ctx.Done():
-		return errors.New("go.micro.client", fmt.Sprintf("%v", ctx.Err()), 408)
+		return errors.Timeout("go.micro.client", fmt.Sprintf("%v", ctx.Err()))
 	default:
 	}
 
@@ -329,7 +330,7 @@ func (r *rpcClient) Call(ctx context.Context, request Request, response interfac
 
 		select {
 		case <-ctx.Done():
-			return errors.New("go.micro.client", fmt.Sprintf("call timeout: %v", ctx.Err()), 408)
+			return errors.Timeout("go.micro.client", fmt.Sprintf("call timeout: %v", ctx.Err()))
 		case err := <-ch:
 			// if the call succeeded lets bail early
 			if err == nil {
@@ -367,7 +368,7 @@ func (r *rpcClient) Stream(ctx context.Context, request Request, opts ...CallOpt
 	// should we noop right here?
 	select {
 	case <-ctx.Done():
-		return nil, errors.New("go.micro.client", fmt.Sprintf("%v", ctx.Err()), 408)
+		return nil, errors.Timeout("go.micro.client", fmt.Sprintf("%v", ctx.Err()))
 	default:
 	}
 
@@ -416,7 +417,7 @@ func (r *rpcClient) Stream(ctx context.Context, request Request, opts ...CallOpt
 
 		select {
 		case <-ctx.Done():
-			return nil, errors.New("go.micro.client", fmt.Sprintf("call timeout: %v", ctx.Err()), 408)
+			return nil, errors.Timeout("go.micro.client", fmt.Sprintf("call timeout: %v", ctx.Err()))
 		case rsp := <-ch:
 			// if the call succeeded lets bail early
 			if rsp.err == nil {
@@ -444,7 +445,11 @@ func (r *rpcClient) Publish(ctx context.Context, msg Message, opts ...PublishOpt
 	if !ok {
 		md = make(map[string]string)
 	}
+
+	id := uuid.New().String()
 	md["Content-Type"] = msg.ContentType()
+	md["X-Micro-Topic"] = msg.Topic()
+	md["X-Micro-Id"] = id
 
 	// encode message body
 	cf, err := r.newCodec(msg.ContentType())
@@ -452,7 +457,14 @@ func (r *rpcClient) Publish(ctx context.Context, msg Message, opts ...PublishOpt
 		return errors.InternalServerError("go.micro.client", err.Error())
 	}
 	b := &buffer{bytes.NewBuffer(nil)}
-	if err := cf(b).Write(&codec.Message{Type: codec.Publication}, msg.Payload()); err != nil {
+	if err := cf(b).Write(&codec.Message{
+		Target: msg.Topic(),
+		Type:   codec.Publication,
+		Header: map[string]string{
+			"X-Micro-Id":    id,
+			"X-Micro-Topic": msg.Topic(),
+		},
+	}, msg.Payload()); err != nil {
 		return errors.InternalServerError("go.micro.client", err.Error())
 	}
 	r.once.Do(func() {

client/rpc_client_test.go

@@ -14,7 +14,7 @@ import (
 func TestCallAddress(t *testing.T) {
 	var called bool
 	service := "test.service"
-	method := "Test.Method"
+	endpoint := "Test.Endpoint"
 	address := "10.1.10.1:8080"
 
 	wrap := func(cf CallFunc) CallFunc {
@@ -25,8 +25,8 @@ func TestCallAddress(t *testing.T) {
 				return fmt.Errorf("expected service: %s got %s", service, req.Service())
 			}
 
-			if req.Method() != method {
-				return fmt.Errorf("expected service: %s got %s", method, req.Method())
+			if req.Endpoint() != endpoint {
+				return fmt.Errorf("expected service: %s got %s", endpoint, req.Endpoint())
 			}
 
 			if addr != address {
@@ -45,7 +45,7 @@ func TestCallAddress(t *testing.T) {
 	)
 	c.Options().Selector.Init(selector.Registry(r))
 
-	req := c.NewRequest(service, method, nil)
+	req := c.NewRequest(service, endpoint, nil)
 
 	// test calling remote address
 	if err := c.Call(context.Background(), req, nil, WithAddress(address)); err != nil {
@@ -60,7 +60,7 @@ func TestCallAddress(t *testing.T) {
 
 func TestCallRetry(t *testing.T) {
 	service := "test.service"
-	method := "Test.Method"
+	endpoint := "Test.Endpoint"
 	address := "10.1.10.1:8080"
 
 	var called int
@@ -84,7 +84,7 @@ func TestCallRetry(t *testing.T) {
 	)
 	c.Options().Selector.Init(selector.Registry(r))
 
-	req := c.NewRequest(service, method, nil)
+	req := c.NewRequest(service, endpoint, nil)
 
 	// test calling remote address
 	if err := c.Call(context.Background(), req, nil, WithAddress(address)); err != nil {
@@ -101,7 +101,7 @@ func TestCallWrapper(t *testing.T) {
 	var called bool
 	id := "test.1"
 	service := "test.service"
-	method := "Test.Method"
+	endpoint := "Test.Endpoint"
 	host := "10.1.10.1"
 	port := 8080
 	address := "10.1.10.1:8080"
@@ -114,8 +114,8 @@ func TestCallWrapper(t *testing.T) {
 				return fmt.Errorf("expected service: %s got %s", service, req.Service())
 			}
 
-			if req.Method() != method {
-				return fmt.Errorf("expected service: %s got %s", method, req.Method())
+			if req.Endpoint() != endpoint {
+				return fmt.Errorf("expected service: %s got %s", endpoint, req.Endpoint())
 			}
 
 			if addr != address {
@@ -146,7 +146,7 @@ func TestCallWrapper(t *testing.T) {
 		},
 	})
 
-	req := c.NewRequest(service, method, nil)
+	req := c.NewRequest(service, endpoint, nil)
 	if err := c.Call(context.Background(), req, nil); err != nil {
 		t.Fatal("call wrapper error", err)
 	}

client/rpc_codec.go

@@ -5,7 +5,11 @@ import (
 	errs "errors"
 
 	"github.com/micro/go-micro/codec"
+	raw "github.com/micro/go-micro/codec/bytes"
+	"github.com/micro/go-micro/codec/grpc"
+	"github.com/micro/go-micro/codec/json"
 	"github.com/micro/go-micro/codec/jsonrpc"
+	"github.com/micro/go-micro/codec/proto"
 	"github.com/micro/go-micro/codec/protorpc"
 	"github.com/micro/go-micro/errors"
 	"github.com/micro/go-micro/transport"
@@ -28,7 +32,7 @@ var (
 	errShutdown = errs.New("connection is shut down")
 )
 
-type rpcPlusCodec struct {
+type rpcCodec struct {
 	client transport.Client
 	codec  codec.Codec
 
@@ -41,37 +45,18 @@ type readWriteCloser struct {
 	rbuf *bytes.Buffer
 }
 
-type clientCodec interface {
-	WriteRequest(*request, interface{}) error
-	ReadResponseHeader(*response) error
-	ReadResponseBody(interface{}) error
-
-	Close() error
-}
-
-type request struct {
-	Service       string
-	ServiceMethod string   // format: "Service.Method"
-	Seq           uint64   // sequence number chosen by client
-	next          *request // for free list in Server
-}
-
-type response struct {
-	ServiceMethod string    // echoes that of the Request
-	Seq           uint64    // echoes that of the request
-	Error         string    // error, if any.
-	next          *response // for free list in Server
-}
-
 var (
-	defaultContentType = "application/octet-stream"
+	DefaultContentType = "application/protobuf"
 
-	defaultCodecs = map[string]codec.NewCodec{
-		"application/json":         jsonrpc.NewCodec,
+	DefaultCodecs = map[string]codec.NewCodec{
+		"application/grpc":         grpc.NewCodec,
+		"application/grpc+json":    grpc.NewCodec,
+		"application/grpc+proto":   grpc.NewCodec,
+		"application/protobuf":     proto.NewCodec,
+		"application/json":         json.NewCodec,
 		"application/json-rpc":     jsonrpc.NewCodec,
-		"application/protobuf":     protorpc.NewCodec,
 		"application/proto-rpc":    protorpc.NewCodec,
-		"application/octet-stream": protorpc.NewCodec,
+		"application/octet-stream": raw.NewCodec,
 	}
 )
 
@@ -89,12 +74,12 @@ func (rwc *readWriteCloser) Close() error {
 	return nil
 }
 
-func newRpcPlusCodec(req *transport.Message, client transport.Client, c codec.NewCodec) *rpcPlusCodec {
+func newRpcCodec(req *transport.Message, client transport.Client, c codec.NewCodec) codec.Codec {
 	rwc := &readWriteCloser{
 		wbuf: bytes.NewBuffer(nil),
 		rbuf: bytes.NewBuffer(nil),
 	}
-	r := &rpcPlusCodec{
+	r := &rpcCodec{
 		buf:    rwc,
 		client: client,
 		codec:  c(rwc),
@@ -103,54 +88,93 @@ func newRpcPlusCodec(req *transport.Message, client transport.Client, c codec.Ne
 	return r
 }
 
-func (c *rpcPlusCodec) WriteRequest(req *request, body interface{}) error {
+func (c *rpcCodec) Write(wm *codec.Message, body interface{}) error {
 	c.buf.wbuf.Reset()
+
 	m := &codec.Message{
-		Id:     req.Seq,
-		Target: req.Service,
-		Method: req.ServiceMethod,
-		Type:   codec.Request,
-		Header: map[string]string{},
+		Id:       wm.Id,
+		Target:   wm.Target,
+		Endpoint: wm.Endpoint,
+		Type:     codec.Request,
+		Header: map[string]string{
+			"X-Micro-Id":       wm.Id,
+			"X-Micro-Service":  wm.Target,
+			"X-Micro-Endpoint": wm.Endpoint,
+		},
 	}
+
 	if err := c.codec.Write(m, body); err != nil {
 		return errors.InternalServerError("go.micro.client.codec", err.Error())
 	}
-	c.req.Body = c.buf.wbuf.Bytes()
+
+	// set body
+	if len(wm.Body) > 0 {
+		c.req.Body = wm.Body
+	} else {
+		c.req.Body = c.buf.wbuf.Bytes()
+	}
+
+	// set header
 	for k, v := range m.Header {
 		c.req.Header[k] = v
 	}
+
+	// send the request
 	if err := c.client.Send(c.req); err != nil {
 		return errors.InternalServerError("go.micro.client.transport", err.Error())
 	}
 	return nil
 }
 
-func (c *rpcPlusCodec) ReadResponseHeader(r *response) error {
+func (c *rpcCodec) ReadHeader(wm *codec.Message, r codec.MessageType) error {
 	var m transport.Message
 	if err := c.client.Recv(&m); err != nil {
 		return errors.InternalServerError("go.micro.client.transport", err.Error())
 	}
 	c.buf.rbuf.Reset()
 	c.buf.rbuf.Write(m.Body)
+
 	var me codec.Message
-	err := c.codec.ReadHeader(&me, codec.Response)
-	r.ServiceMethod = me.Method
-	r.Seq = me.Id
-	r.Error = me.Error
+	// set headers
+	me.Header = m.Header
+
+	// read header
+	err := c.codec.ReadHeader(&me, r)
+	wm.Endpoint = me.Endpoint
+	wm.Id = me.Id
+	wm.Error = me.Error
+
+	// check error in header
+	if len(me.Error) == 0 {
+		wm.Error = me.Header["X-Micro-Error"]
+	}
+
+	// check method in header
+	if len(me.Endpoint) == 0 {
+		wm.Endpoint = me.Header["X-Micro-Endpoint"]
+	}
+
+	if len(me.Id) == 0 {
+		wm.Id = me.Header["X-Micro-Id"]
+	}
+
+	// return header error
 	if err != nil {
 		return errors.InternalServerError("go.micro.client.codec", err.Error())
 	}
+
 	return nil
 }
 
-func (c *rpcPlusCodec) ReadResponseBody(b interface{}) error {
+func (c *rpcCodec) ReadBody(b interface{}) error {
+	// read body
 	if err := c.codec.ReadBody(b); err != nil {
 		return errors.InternalServerError("go.micro.client.codec", err.Error())
 	}
 	return nil
 }
 
-func (c *rpcPlusCodec) Close() error {
+func (c *rpcCodec) Close() error {
 	c.buf.Close()
 	c.codec.Close()
 	if err := c.client.Close(); err != nil {
@@ -158,3 +182,7 @@ func (c *rpcPlusCodec) Close() error {
 	}
 	return nil
 }
+
+func (c *rpcCodec) String() string {
+	return "rpc"
+}

client/rpc_request.go

@@ -1,14 +1,19 @@
 package client
 
+import (
+	"github.com/micro/go-micro/codec"
+)
+
 type rpcRequest struct {
 	service     string
-	method      string
+	endpoint    string
 	contentType string
-	request     interface{}
+	codec       codec.Codec
+	body        interface{}
 	opts        RequestOptions
 }
 
-func newRequest(service, method string, request interface{}, contentType string, reqOpts ...RequestOption) Request {
+func newRequest(service, endpoint string, request interface{}, contentType string, reqOpts ...RequestOption) Request {
 	var opts RequestOptions
 
 	for _, o := range reqOpts {
@@ -22,8 +27,8 @@ func newRequest(service, method string, request interface{}, contentType string,
 
 	return &rpcRequest{
 		service:     service,
-		method:      method,
-		request:     request,
+		endpoint:    endpoint,
+		body:        request,
 		contentType: contentType,
 		opts:        opts,
 	}
@@ -37,12 +42,16 @@ func (r *rpcRequest) Service() string {
 	return r.service
 }
 
-func (r *rpcRequest) Method() string {
-	return r.method
+func (r *rpcRequest) Endpoint() string {
+	return r.endpoint
 }
 
-func (r *rpcRequest) Request() interface{} {
-	return r.request
+func (r *rpcRequest) Body() interface{} {
+	return r.body
+}
+
+func (r *rpcRequest) Codec() codec.Writer {
+	return r.codec
 }
 
 func (r *rpcRequest) Stream() bool {

client/rpc_request_test.go

@@ -5,19 +5,19 @@ import (
 )
 
 func TestRequestOptions(t *testing.T) {
-	r := newRequest("service", "method", nil, "application/json")
+	r := newRequest("service", "endpoint", nil, "application/json")
 	if r.Service() != "service" {
 		t.Fatalf("expected 'service' got %s", r.Service())
 	}
-	if r.Method() != "method" {
-		t.Fatalf("expected 'method' got %s", r.Method())
+	if r.Endpoint() != "endpoint" {
+		t.Fatalf("expected 'endpoint' got %s", r.Endpoint())
 	}
 	if r.ContentType() != "application/json" {
-		t.Fatalf("expected 'method' got %s", r.ContentType())
+		t.Fatalf("expected 'endpoint' got %s", r.ContentType())
 	}
 
-	r2 := newRequest("service", "method", nil, "application/json", WithContentType("application/protobuf"))
+	r2 := newRequest("service", "endpoint", nil, "application/json", WithContentType("application/protobuf"))
 	if r2.ContentType() != "application/protobuf" {
-		t.Fatalf("expected 'method' got %s", r2.ContentType())
+		t.Fatalf("expected 'endpoint' got %s", r2.ContentType())
 	}
 }

client/rpc_response.go

@@ -0,0 +1,35 @@
+package client
+
+import (
+	"github.com/micro/go-micro/codec"
+	"github.com/micro/go-micro/transport"
+)
+
+type rpcResponse struct {
+	header map[string]string
+	body   []byte
+	socket transport.Socket
+	codec  codec.Codec
+}
+
+func (r *rpcResponse) Codec() codec.Writer {
+	return r.codec
+}
+
+func (r *rpcResponse) Header() map[string]string {
+	return r.header
+}
+
+func (r *rpcResponse) Read() ([]byte, error) {
+	var msg transport.Message
+
+	if err := r.socket.Recv(&msg); err != nil {
+		return nil, err
+	}
+
+	// set internals
+	r.header = msg.Header
+	r.body = msg.Body
+
+	return msg.Body, nil
+}

client/rpc_stream.go

@@ -4,16 +4,18 @@ import (
 	"context"
 	"io"
 	"sync"
+
+	"github.com/micro/go-micro/codec"
 )
 
 // Implements the streamer interface
 type rpcStream struct {
 	sync.RWMutex
-	seq     uint64
+	id      string
 	closed  chan bool
 	err     error
 	request Request
-	codec   clientCodec
+	codec   codec.Codec
 	context context.Context
 }
 
@@ -43,18 +45,18 @@ func (r *rpcStream) Send(msg interface{}) error {
 		return errShutdown
 	}
 
-	seq := r.seq
-
-	req := request{
-		Service:       r.request.Service(),
-		Seq:           seq,
-		ServiceMethod: r.request.Method(),
+	req := codec.Message{
+		Id:       r.id,
+		Target:   r.request.Service(),
+		Endpoint: r.request.Endpoint(),
+		Type:     codec.Request,
 	}
 
-	if err := r.codec.WriteRequest(&req, msg); err != nil {
+	if err := r.codec.Write(&req, msg); err != nil {
 		r.err = err
 		return err
 	}
+
 	return nil
 }
 
@@ -67,8 +69,9 @@ func (r *rpcStream) Recv(msg interface{}) error {
 		return errShutdown
 	}
 
-	var resp response
-	if err := r.codec.ReadResponseHeader(&resp); err != nil {
+	var resp codec.Message
+
+	if err := r.codec.ReadHeader(&resp, codec.Response); err != nil {
 		if err == io.EOF && !r.isClosed() {
 			r.err = io.ErrUnexpectedEOF
 			return io.ErrUnexpectedEOF
@@ -87,11 +90,11 @@ func (r *rpcStream) Recv(msg interface{}) error {
 		} else {
 			r.err = io.EOF
 		}
-		if err := r.codec.ReadResponseBody(nil); err != nil {
+		if err := r.codec.ReadBody(nil); err != nil {
 			r.err = err
 		}
 	default:
-		if err := r.codec.ReadResponseBody(msg); err != nil {
+		if err := r.codec.ReadBody(msg); err != nil {
 			r.err = err
 		}
 	}

cmd/cmd.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/micro/cli"
+	"github.com/micro/go-log"
 	"github.com/micro/go-micro/client"
 	"github.com/micro/go-micro/server"
 
@@ -20,11 +21,13 @@ import (
 	// registries
 	"github.com/micro/go-micro/registry"
 	"github.com/micro/go-micro/registry/consul"
+	"github.com/micro/go-micro/registry/gossip"
 	"github.com/micro/go-micro/registry/mdns"
 
 	// selectors
 	"github.com/micro/go-micro/selector"
-	"github.com/micro/go-micro/selector/cache"
+	"github.com/micro/go-micro/selector/dns"
+	"github.com/micro/go-micro/selector/static"
 
 	// transports
 	"github.com/micro/go-micro/transport"
@@ -147,7 +150,6 @@ var (
 			Name:   "selector",
 			EnvVar: "MICRO_SELECTOR",
 			Usage:  "Selector used to pick nodes for querying",
-			Value:  "cache",
 		},
 		cli.StringFlag{
 			Name:   "transport",
@@ -171,12 +173,15 @@ var (
 
 	DefaultRegistries = map[string]func(...registry.Option) registry.Registry{
 		"consul": consul.NewRegistry,
+		"gossip": gossip.NewRegistry,
 		"mdns":   mdns.NewRegistry,
 	}
 
 	DefaultSelectors = map[string]func(...selector.Option) selector.Selector{
 		"default": selector.NewSelector,
-		"cache":   cache.NewSelector,
+		"dns":     dns.NewSelector,
+		"cache":   selector.NewSelector,
+		"static":  static.NewSelector,
 	}
 
 	DefaultServers = map[string]func(...server.Option) server.Server{
@@ -299,10 +304,15 @@ func (c *cmd) Before(ctx *cli.Context) error {
 		serverOpts = append(serverOpts, server.Registry(*c.opts.Registry))
 		clientOpts = append(clientOpts, client.Registry(*c.opts.Registry))
 
-		(*c.opts.Selector).Init(selector.Registry(*c.opts.Registry))
+		if err := (*c.opts.Selector).Init(selector.Registry(*c.opts.Registry)); err != nil {
+			log.Fatalf("Error configuring registry: %v", err)
+		}
+
 		clientOpts = append(clientOpts, client.Selector(*c.opts.Selector))
 
-		(*c.opts.Broker).Init(broker.Registry(*c.opts.Registry))
+		if err := (*c.opts.Broker).Init(broker.Registry(*c.opts.Registry)); err != nil {
+			log.Fatalf("Error configuring broker: %v", err)
+		}
 	}
 
 	// Set the selector
@@ -347,15 +357,21 @@ func (c *cmd) Before(ctx *cli.Context) error {
 	}
 
 	if len(ctx.String("broker_address")) > 0 {
-		(*c.opts.Broker).Init(broker.Addrs(strings.Split(ctx.String("broker_address"), ",")...))
+		if err := (*c.opts.Broker).Init(broker.Addrs(strings.Split(ctx.String("broker_address"), ",")...)); err != nil {
+			log.Fatalf("Error configuring broker: %v", err)
+		}
 	}
 
 	if len(ctx.String("registry_address")) > 0 {
-		(*c.opts.Registry).Init(registry.Addrs(strings.Split(ctx.String("registry_address"), ",")...))
+		if err := (*c.opts.Registry).Init(registry.Addrs(strings.Split(ctx.String("registry_address"), ",")...)); err != nil {
+			log.Fatalf("Error configuring registry: %v", err)
+		}
 	}
 
 	if len(ctx.String("transport_address")) > 0 {
-		(*c.opts.Transport).Init(transport.Addrs(strings.Split(ctx.String("transport_address"), ",")...))
+		if err := (*c.opts.Transport).Init(transport.Addrs(strings.Split(ctx.String("transport_address"), ",")...)); err != nil {
+			log.Fatalf("Error configuring transport: %v", err)
+		}
 	}
 
 	if len(ctx.String("server_name")) > 0 {
@@ -410,12 +426,16 @@ func (c *cmd) Before(ctx *cli.Context) error {
 	// We have some command line opts for the server.
 	// Lets set it up
 	if len(serverOpts) > 0 {
-		(*c.opts.Server).Init(serverOpts...)
+		if err := (*c.opts.Server).Init(serverOpts...); err != nil {
+			log.Fatalf("Error configuring server: %v", err)
+		}
 	}
 
 	// Use an init option?
 	if len(clientOpts) > 0 {
-		(*c.opts.Client).Init(clientOpts...)
+		if err := (*c.opts.Client).Init(clientOpts...); err != nil {
+			log.Fatalf("Error configuring client: %v", err)
+		}
 	}
 
 	return nil

codec/bytes/bytes.go

@@ -0,0 +1,58 @@
+// Package bytes provides a bytes codec which does not encode or decode anything
+package bytes
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+
+	"github.com/micro/go-micro/codec"
+)
+
+type Codec struct {
+	Conn io.ReadWriteCloser
+}
+
+func (c *Codec) ReadHeader(m *codec.Message, t codec.MessageType) error {
+	return nil
+}
+
+func (c *Codec) ReadBody(b interface{}) error {
+	v, ok := b.(*[]byte)
+	if !ok {
+		return fmt.Errorf("failed to read body: %v is not type of *[]byte", b)
+	}
+
+	// read bytes
+	buf, err := ioutil.ReadAll(c.Conn)
+	if err != nil {
+		return err
+	}
+
+	// set bytes
+	*v = buf
+	return nil
+}
+
+func (c *Codec) Write(m *codec.Message, b interface{}) error {
+	v, ok := b.(*[]byte)
+	if !ok {
+		return fmt.Errorf("failed to write: %v is not type of *[]byte", b)
+	}
+	_, err := c.Conn.Write(*v)
+	return err
+}
+
+func (c *Codec) Close() error {
+	return c.Conn.Close()
+}
+
+func (c *Codec) String() string {
+	return "bytes"
+}
+
+func NewCodec(c io.ReadWriteCloser) codec.Codec {
+	return &Codec{
+		Conn: c,
+	}
+}

codec/bytes/marshaler.go

@@ -0,0 +1,38 @@
+package bytes
+
+import (
+	"errors"
+)
+
+type Marshaler struct{}
+
+type Message struct {
+	Header map[string]string
+	Body   []byte
+}
+
+func (n Marshaler) Marshal(v interface{}) ([]byte, error) {
+	switch v.(type) {
+	case []byte:
+		return v.([]byte), nil
+	case *Message:
+		return v.(*Message).Body, nil
+	}
+	return nil, errors.New("invalid message")
+}
+
+func (n Marshaler) Unmarshal(d []byte, v interface{}) error {
+	switch v.(type) {
+	case *[]byte:
+		ve := v.(*[]byte)
+		*ve = d
+	case *Message:
+		ve := v.(*Message)
+		ve.Body = d
+	}
+	return errors.New("invalid message")
+}
+
+func (n Marshaler) String() string {
+	return "bytes"
+}

codec/codec.go

@@ -23,10 +23,26 @@ type NewCodec func(io.ReadWriteCloser) Codec
 // connection. ReadBody may be called with a nil argument to force the
 // body to be read and discarded.
 type Codec interface {
+	Reader
+	Writer
+	Close() error
+	String() string
+}
+
+type Reader interface {
 	ReadHeader(*Message, MessageType) error
 	ReadBody(interface{}) error
+}
+
+type Writer interface {
 	Write(*Message, interface{}) error
-	Close() error
+}
+
+// Marshaler is a simple encoding interface used for the broker/transport
+// where headers are not supported by the underlying implementation.
+type Marshaler interface {
+	Marshal(interface{}) ([]byte, error)
+	Unmarshal([]byte, interface{}) error
 	String() string
 }
 
@@ -34,10 +50,13 @@ type Codec interface {
 // the communication, likely followed by the body.
 // In the case of an error, body may be nil.
 type Message struct {
-	Id     uint64
-	Type   MessageType
-	Target string
-	Method string
-	Error  string
+	Id       string
+	Type     MessageType
+	Target   string
+	Endpoint string
+	Error    string
+
+	// The values read from the socket
 	Header map[string]string
+	Body   []byte
 }

codec/grpc/grpc.go

@@ -0,0 +1,132 @@
+// Package grpc provides a grpc codec
+package grpc
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"strings"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/micro/go-micro/codec"
+)
+
+type Codec struct {
+	Conn        io.ReadWriteCloser
+	ContentType string
+}
+
+func (c *Codec) ReadHeader(m *codec.Message, t codec.MessageType) error {
+	if ct := m.Header["Content-Type"]; len(ct) > 0 {
+		c.ContentType = ct
+	}
+
+	if ct := m.Header["content-type"]; len(ct) > 0 {
+		c.ContentType = ct
+	}
+
+	// service method
+	path := m.Header[":path"]
+	if len(path) == 0 || path[0] != '/' {
+		m.Target = m.Header["X-Micro-Service"]
+		m.Endpoint = m.Header["X-Micro-Endpoint"]
+	} else {
+		// [ , a.package.Foo, Bar]
+		parts := strings.Split(path, "/")
+		if len(parts) != 3 {
+			return errors.New("Unknown request path")
+		}
+		service := strings.Split(parts[1], ".")
+		m.Endpoint = strings.Join([]string{service[len(service)-1], parts[2]}, ".")
+		m.Target = strings.Join(service[:len(service)-1], ".")
+	}
+
+	return nil
+}
+
+func (c *Codec) ReadBody(b interface{}) error {
+	// no body
+	if b == nil {
+		return nil
+	}
+
+	_, buf, err := decode(c.Conn)
+	if err != nil {
+		return err
+	}
+
+	switch c.ContentType {
+	case "application/grpc+json":
+		return json.Unmarshal(buf, b)
+	case "application/grpc+proto", "application/grpc":
+		return proto.Unmarshal(buf, b.(proto.Message))
+	}
+
+	return errors.New("Unsupported Content-Type")
+}
+
+func (c *Codec) Write(m *codec.Message, b interface{}) error {
+	var buf []byte
+	var err error
+
+	if ct := m.Header["Content-Type"]; len(ct) > 0 {
+		c.ContentType = ct
+	}
+
+	if ct := m.Header["content-type"]; len(ct) > 0 {
+		c.ContentType = ct
+	}
+
+	switch m.Type {
+	case codec.Request:
+		parts := strings.Split(m.Endpoint, ".")
+		m.Header[":method"] = "POST"
+		m.Header[":path"] = fmt.Sprintf("/%s.%s/%s", m.Target, parts[0], parts[1])
+		m.Header[":proto"] = "HTTP/2.0"
+		m.Header["te"] = "trailers"
+		m.Header["user-agent"] = "grpc-go/1.0.0"
+		m.Header[":authority"] = m.Target
+		m.Header["content-type"] = c.ContentType
+	case codec.Response:
+		m.Header["Trailer"] = "grpc-status, grpc-message"
+		m.Header["grpc-status"] = "0"
+		m.Header["grpc-message"] = ""
+	}
+
+	// marshal content
+	switch c.ContentType {
+	case "application/grpc+json":
+		buf, err = json.Marshal(b)
+	case "application/grpc+proto", "application/grpc":
+		pb, ok := b.(proto.Message)
+		if ok {
+			buf, err = proto.Marshal(pb)
+		}
+	default:
+		err = errors.New("Unsupported Content-Type")
+	}
+	// check error
+	if err != nil {
+		m.Header["grpc-status"] = "8"
+		m.Header["grpc-message"] = err.Error()
+		return err
+	}
+
+	return encode(0, buf, c.Conn)
+}
+
+func (c *Codec) Close() error {
+	return c.Conn.Close()
+}
+
+func (c *Codec) String() string {
+	return "grpc"
+}
+
+func NewCodec(c io.ReadWriteCloser) codec.Codec {
+	return &Codec{
+		Conn:        c,
+		ContentType: "application/grpc",
+	}
+}

codec/grpc/util.go

@@ -0,0 +1,70 @@
+package grpc
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+)
+
+var (
+	maxMessageSize = 1024 * 1024 * 4
+	maxInt         = int(^uint(0) >> 1)
+)
+
+func decode(r io.Reader) (uint8, []byte, error) {
+	header := make([]byte, 5)
+
+	// read the header
+	if _, err := r.Read(header[:]); err != nil {
+		return uint8(0), nil, err
+	}
+
+	// get encoding format e.g compressed
+	cf := uint8(header[0])
+
+	// get message length
+	length := binary.BigEndian.Uint32(header[1:])
+
+	// no encoding format
+	if length == 0 {
+		return cf, nil, nil
+	}
+
+	//
+	if int64(length) > int64(maxInt) {
+		return cf, nil, fmt.Errorf("grpc: received message larger than max length allowed on current machine (%d vs. %d)", length, maxInt)
+	}
+	if int(length) > maxMessageSize {
+		return cf, nil, fmt.Errorf("grpc: received message larger than max (%d vs. %d)", length, maxMessageSize)
+	}
+
+	msg := make([]byte, int(length))
+
+	if _, err := r.Read(msg); err != nil {
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+		return cf, nil, err
+	}
+
+	return cf, msg, nil
+}
+
+func encode(cf uint8, buf []byte, w io.Writer) error {
+	header := make([]byte, 5)
+
+	// set compression
+	header[0] = byte(cf)
+
+	// write length as header
+	binary.BigEndian.PutUint32(header[1:], uint32(len(buf)))
+
+	// read the header
+	if _, err := w.Write(header[:]); err != nil {
+		return err
+	}
+
+	// write the buffer
+	_, err := w.Write(buf)
+	return err
+}

codec/json/json.go

@@ -0,0 +1,49 @@
+// Package json provides a json codec
+package json
+
+import (
+	"encoding/json"
+	"io"
+
+	"github.com/micro/go-micro/codec"
+)
+
+type Codec struct {
+	Conn    io.ReadWriteCloser
+	Encoder *json.Encoder
+	Decoder *json.Decoder
+}
+
+func (c *Codec) ReadHeader(m *codec.Message, t codec.MessageType) error {
+	return nil
+}
+
+func (c *Codec) ReadBody(b interface{}) error {
+	if b == nil {
+		return nil
+	}
+	return c.Decoder.Decode(b)
+}
+
+func (c *Codec) Write(m *codec.Message, b interface{}) error {
+	if b == nil {
+		return nil
+	}
+	return c.Encoder.Encode(b)
+}
+
+func (c *Codec) Close() error {
+	return c.Conn.Close()
+}
+
+func (c *Codec) String() string {
+	return "json"
+}
+
+func NewCodec(c io.ReadWriteCloser) codec.Codec {
+	return &Codec{
+		Conn:    c,
+		Decoder: json.NewDecoder(c),
+		Encoder: json.NewEncoder(c),
+	}
+}

codec/json/marshaler.go

@@ -0,0 +1,19 @@
+package json
+
+import (
+	"encoding/json"
+)
+
+type Marshaler struct{}
+
+func (j Marshaler) Marshal(v interface{}) ([]byte, error) {
+	return json.Marshal(v)
+}
+
+func (j Marshaler) Unmarshal(d []byte, v interface{}) error {
+	return json.Unmarshal(d, v)
+}
+
+func (j Marshaler) String() string {
+	return "json"
+}

codec/jsonrpc/client.go

@@ -19,17 +19,17 @@ type clientCodec struct {
 	resp clientResponse
 
 	sync.Mutex
-	pending map[uint64]string
+	pending map[interface{}]string
 }
 
 type clientRequest struct {
 	Method string         `json:"method"`
 	Params [1]interface{} `json:"params"`
-	ID     uint64         `json:"id"`
+	ID     interface{}    `json:"id"`
 }
 
 type clientResponse struct {
-	ID     uint64           `json:"id"`
+	ID     interface{}      `json:"id"`
 	Result *json.RawMessage `json:"result"`
 	Error  interface{}      `json:"error"`
 }
@@ -39,15 +39,15 @@ func newClientCodec(conn io.ReadWriteCloser) *clientCodec {
 		dec:     json.NewDecoder(conn),
 		enc:     json.NewEncoder(conn),
 		c:       conn,
-		pending: make(map[uint64]string),
+		pending: make(map[interface{}]string),
 	}
 }
 
 func (c *clientCodec) Write(m *codec.Message, b interface{}) error {
 	c.Lock()
-	c.pending[m.Id] = m.Method
+	c.pending[m.Id] = m.Endpoint
 	c.Unlock()
-	c.req.Method = m.Method
+	c.req.Method = m.Endpoint
 	c.req.Params[0] = b
 	c.req.ID = m.Id
 	return c.enc.Encode(&c.req)
@@ -66,12 +66,12 @@ func (c *clientCodec) ReadHeader(m *codec.Message) error {
 	}
 
 	c.Lock()
-	m.Method = c.pending[c.resp.ID]
+	m.Endpoint = c.pending[c.resp.ID]
 	delete(c.pending, c.resp.ID)
 	c.Unlock()
 
 	m.Error = ""
-	m.Id = c.resp.ID
+	m.Id = fmt.Sprintf("%v", c.resp.ID)
 	if c.resp.Error != nil {
 		x, ok := c.resp.Error.(string)
 		if !ok {

codec/jsonrpc/jsonrpc.go

@@ -31,7 +31,7 @@ func (j *jsonCodec) Write(m *codec.Message, b interface{}) error {
 	switch m.Type {
 	case codec.Request:
 		return j.c.Write(m, b)
-	case codec.Response:
+	case codec.Response, codec.Error:
 		return j.s.Write(m, b)
 	case codec.Publication:
 		data, err := json.Marshal(b)

codec/jsonrpc/server.go

@@ -2,9 +2,8 @@ package jsonrpc
 
 import (
 	"encoding/json"
-	"errors"
+	"fmt"
 	"io"
-	"sync"
 
 	"github.com/micro/go-micro/codec"
 )
@@ -17,30 +16,25 @@ type serverCodec struct {
 	// temporary work space
 	req  serverRequest
 	resp serverResponse
-
-	sync.Mutex
-	seq     uint64
-	pending map[uint64]*json.RawMessage
 }
 
 type serverRequest struct {
 	Method string           `json:"method"`
 	Params *json.RawMessage `json:"params"`
-	ID     *json.RawMessage `json:"id"`
+	ID     interface{}      `json:"id"`
 }
 
 type serverResponse struct {
-	ID     *json.RawMessage `json:"id"`
-	Result interface{}      `json:"result"`
-	Error  interface{}      `json:"error"`
+	ID     interface{} `json:"id"`
+	Result interface{} `json:"result"`
+	Error  interface{} `json:"error"`
 }
 
 func newServerCodec(conn io.ReadWriteCloser) *serverCodec {
 	return &serverCodec{
-		dec:     json.NewDecoder(conn),
-		enc:     json.NewEncoder(conn),
-		c:       conn,
-		pending: make(map[uint64]*json.RawMessage),
+		dec: json.NewDecoder(conn),
+		enc: json.NewEncoder(conn),
+		c:   conn,
 	}
 }
 
@@ -50,7 +44,7 @@ func (r *serverRequest) reset() {
 		*r.Params = (*r.Params)[0:0]
 	}
 	if r.ID != nil {
-		*r.ID = (*r.ID)[0:0]
+		r.ID = nil
 	}
 }
 
@@ -59,15 +53,9 @@ func (c *serverCodec) ReadHeader(m *codec.Message) error {
 	if err := c.dec.Decode(&c.req); err != nil {
 		return err
 	}
-	m.Method = c.req.Method
-
-	c.Lock()
-	c.seq++
-	c.pending[c.seq] = c.req.ID
+	m.Endpoint = c.req.Method
+	m.Id = fmt.Sprintf("%v", c.req.ID)
 	c.req.ID = nil
-	m.Id = c.seq
-	c.Unlock()
-
 	return nil
 }
 
@@ -84,19 +72,7 @@ var null = json.RawMessage([]byte("null"))
 
 func (c *serverCodec) Write(m *codec.Message, x interface{}) error {
 	var resp serverResponse
-	c.Lock()
-	b, ok := c.pending[m.Id]
-	if !ok {
-		c.Unlock()
-		return errors.New("invalid sequence number in response")
-	}
-	c.Unlock()
-
-	if b == nil {
-		// Invalid request so no id.  Use JSON null.
-		b = &null
-	}
-	resp.ID = b
+	resp.ID = m.Id
 	resp.Result = x
 	if m.Error == "" {
 		resp.Error = nil

codec/proto/marshaler.go

@@ -0,0 +1,19 @@
+package proto
+
+import (
+	"github.com/golang/protobuf/proto"
+)
+
+type Marshaler struct{}
+
+func (Marshaler) Marshal(v interface{}) ([]byte, error) {
+	return proto.Marshal(v.(proto.Message))
+}
+
+func (Marshaler) Unmarshal(data []byte, v interface{}) error {
+	return proto.Unmarshal(data, v.(proto.Message))
+}
+
+func (Marshaler) Name() string {
+	return "proto"
+}

codec/proto/proto.go

@@ -0,0 +1,56 @@
+// Package proto provides a proto codec
+package proto
+
+import (
+	"io"
+	"io/ioutil"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/micro/go-micro/codec"
+)
+
+type Codec struct {
+	Conn io.ReadWriteCloser
+}
+
+func (c *Codec) ReadHeader(m *codec.Message, t codec.MessageType) error {
+	return nil
+}
+
+func (c *Codec) ReadBody(b interface{}) error {
+	buf, err := ioutil.ReadAll(c.Conn)
+	if err != nil {
+		return err
+	}
+	if b == nil {
+		return nil
+	}
+	return proto.Unmarshal(buf, b.(proto.Message))
+}
+
+func (c *Codec) Write(m *codec.Message, b interface{}) error {
+	p, ok := b.(proto.Message)
+	if !ok {
+		return nil
+	}
+	buf, err := proto.Marshal(p)
+	if err != nil {
+		return err
+	}
+	_, err = c.Conn.Write(buf)
+	return err
+}
+
+func (c *Codec) Close() error {
+	return c.Conn.Close()
+}
+
+func (c *Codec) String() string {
+	return "proto"
+}
+
+func NewCodec(c io.ReadWriteCloser) codec.Codec {
+	return &Codec{
+		Conn: c,
+	}
+}

codec/protorpc/protorpc.go

@@ -5,6 +5,7 @@ import (
 	"bytes"
 	"fmt"
 	"io"
+	"strconv"
 	"sync"
 
 	"github.com/golang/protobuf/proto"
@@ -31,13 +32,22 @@ func (c *protoCodec) String() string {
 	return "proto-rpc"
 }
 
+func id(id string) *uint64 {
+	p, err := strconv.ParseInt(id, 10, 64)
+	if err != nil {
+		p = 0
+	}
+	i := uint64(p)
+	return &i
+}
+
 func (c *protoCodec) Write(m *codec.Message, b interface{}) error {
 	switch m.Type {
 	case codec.Request:
 		c.Lock()
 		defer c.Unlock()
 		// This is protobuf, of course we copy it.
-		pbr := &Request{ServiceMethod: &m.Method, Seq: &m.Id}
+		pbr := &Request{ServiceMethod: &m.Endpoint, Seq: id(m.Id)}
 		data, err := proto.Marshal(pbr)
 		if err != nil {
 			return err
@@ -60,10 +70,10 @@ func (c *protoCodec) Write(m *codec.Message, b interface{}) error {
 				return err
 			}
 		}
-	case codec.Response:
+	case codec.Response, codec.Error:
 		c.Lock()
 		defer c.Unlock()
-		rtmp := &Response{ServiceMethod: &m.Method, Seq: &m.Id, Error: &m.Error}
+		rtmp := &Response{ServiceMethod: &m.Endpoint, Seq: id(m.Id), Error: &m.Error}
 		data, err := proto.Marshal(rtmp)
 		if err != nil {
 			return err
@@ -116,8 +126,8 @@ func (c *protoCodec) ReadHeader(m *codec.Message, mt codec.MessageType) error {
 		if err != nil {
 			return err
 		}
-		m.Method = rtmp.GetServiceMethod()
-		m.Id = rtmp.GetSeq()
+		m.Endpoint = rtmp.GetServiceMethod()
+		m.Id = fmt.Sprintf("%d", rtmp.GetSeq())
 	case codec.Response:
 		data, err := ReadNetString(c.rwc)
 		if err != nil {
@@ -128,8 +138,8 @@ func (c *protoCodec) ReadHeader(m *codec.Message, mt codec.MessageType) error {
 		if err != nil {
 			return err
 		}
-		m.Method = rtmp.GetServiceMethod()
-		m.Id = rtmp.GetSeq()
+		m.Endpoint = rtmp.GetServiceMethod()
+		m.Id = fmt.Sprintf("%d", rtmp.GetSeq())
 		m.Error = rtmp.GetError()
 	case codec.Publication:
 		_, err := io.Copy(c.buf, c.rwc)

errors/errors.go

@@ -92,13 +92,13 @@ func MethodNotAllowed(id, format string, a ...interface{}) error {
 	}
 }
 
-// InternalServerError generates a 500 error.
-func InternalServerError(id, format string, a ...interface{}) error {
+// Timeout generates a 408 error.
+func Timeout(id, format string, a ...interface{}) error {
 	return &Error{
 		Id:     id,
-		Code:   500,
+		Code:   408,
 		Detail: fmt.Sprintf(format, a...),
-		Status: http.StatusText(500),
+		Status: http.StatusText(408),
 	}
 }
 
@@ -111,3 +111,13 @@ func Conflict(id, format string, a ...interface{}) error {
 		Status: http.StatusText(409),
 	}
 }
+
+// InternalServerError generates a 500 error.
+func InternalServerError(id, format string, a ...interface{}) error {
+	return &Error{
+		Id:     id,
+		Code:   500,
+		Detail: fmt.Sprintf(format, a...),
+		Status: http.StatusText(500),
+	}
+}

options.go

@@ -174,6 +174,7 @@ func RegisterInterval(t time.Duration) Option {
 
 // WrapClient is a convenience method for wrapping a Client with
 // some middleware component. A list of wrappers can be provided.
+// Wrappers are applied in reverse order so the last is executed first.
 func WrapClient(w ...client.Wrapper) Option {
 	return func(o *Options) {
 		// apply in reverse

registry/consul/consul.go

@@ -1,9 +1,11 @@
+// Package consul provides a consul based registry and is the default discovery system
 package consul
 
 import (
 	"github.com/micro/go-micro/registry"
 )
 
+// NewRegistry returns a new consul registry
 func NewRegistry(opts ...registry.Option) registry.Registry {
 	return registry.NewRegistry(opts...)
 }

registry/consul/options.go

@@ -27,6 +27,40 @@ func Config(c *consul.Config) registry.Option {
 	}
 }
 
+// AllowStale sets whether any Consul server (non-leader) can service
+// a read. This allows for lower latency and higher throughput
+// at the cost of potentially stale data.
+// Works similar to Consul DNS Config option [1].
+// Defaults to true.
+//
+// [1] https://www.consul.io/docs/agent/options.html#allow_stale
+//
+func AllowStale(v bool) registry.Option {
+	return func(o *registry.Options) {
+		if o.Context == nil {
+			o.Context = context.Background()
+		}
+		o.Context = context.WithValue(o.Context, "consul_allow_stale", v)
+	}
+}
+
+// QueryOptions specifies the QueryOptions to be used when calling
+// Consul. See `Consul API` for more information [1].
+//
+// [1] https://godoc.org/github.com/hashicorp/consul/api#QueryOptions
+//
+func QueryOptions(q *consul.QueryOptions) registry.Option {
+	return func(o *registry.Options) {
+		if q == nil {
+			return
+		}
+		if o.Context == nil {
+			o.Context = context.Background()
+		}
+		o.Context = context.WithValue(o.Context, "consul_query_options", q)
+	}
+}
+
 //
 // TCPCheck will tell the service provider to check the service address
 // and port every `t` interval. It will enabled only if `t` is greater than 0.

registry/consul_registry.go

@@ -22,8 +22,12 @@ type consulRegistry struct {
 	// connect enabled
 	connect bool
 
+	queryOptions *consul.QueryOptions
+
 	sync.Mutex
 	register map[string]uint64
+	// lastChecked tracks when a node was last checked as existing in Consul
+	lastChecked map[string]time.Time
 }
 
 func getDeregisterTTL(t time.Duration) time.Duration {
@@ -78,6 +82,14 @@ func configure(c *consulRegistry, opts ...Option) {
 		if cn, ok := c.opts.Context.Value("consul_connect").(bool); ok {
 			c.connect = cn
 		}
+
+		// Use the consul query options passed in the options, if available
+		if qo, ok := c.opts.Context.Value("consul_query_options").(*consul.QueryOptions); ok && qo != nil {
+			c.queryOptions = qo
+		}
+		if as, ok := c.opts.Context.Value("consul_allow_stale").(bool); ok {
+			c.queryOptions.AllowStale = as
+		}
 	}
 
 	// check if there are any addrs
@@ -118,8 +130,12 @@ func configure(c *consulRegistry, opts ...Option) {
 
 func newConsulRegistry(opts ...Option) Registry {
 	cr := &consulRegistry{
-		opts:     Options{},
-		register: make(map[string]uint64),
+		opts:        Options{},
+		register:    make(map[string]uint64),
+		lastChecked: make(map[string]time.Time),
+		queryOptions: &consul.QueryOptions{
+			AllowStale: true,
+		},
 	}
 	configure(cr, opts...)
 	return cr
@@ -135,9 +151,10 @@ func (c *consulRegistry) Deregister(s *Service) error {
 		return errors.New("Require at least one node")
 	}
 
-	// delete our hash of the service
+	// delete our hash and time check of the service
 	c.Lock()
 	delete(c.register, s.Name)
+	delete(c.lastChecked, s.Name)
 	c.Unlock()
 
 	node := s.Nodes[0]
@@ -173,15 +190,20 @@ func (c *consulRegistry) Register(s *Service, opts ...RegisterOption) error {
 	// use first node
 	node := s.Nodes[0]
 
-	// get existing hash
+	// get existing hash and last checked time
 	c.Lock()
 	v, ok := c.register[s.Name]
+	lastChecked := c.lastChecked[s.Name]
 	c.Unlock()
 
 	// if it's already registered and matches then just pass the check
 	if ok && v == h {
 		if options.TTL == time.Duration(0) {
-			services, _, err := c.Client.Health().Checks(s.Name, nil)
+			// ensure that our service hasn't been deregistered by Consul
+			if time.Since(lastChecked) <= getDeregisterTTL(regInterval) {
+				return nil
+			}
+			services, _, err := c.Client.Health().Checks(s.Name, c.queryOptions)
 			if err == nil {
 				for _, v := range services {
 					if v.ServiceID == node.Id {
@@ -245,9 +267,10 @@ func (c *consulRegistry) Register(s *Service, opts ...RegisterOption) error {
 		return err
 	}
 
-	// save our hash of the service
+	// save our hash and time check of the service
 	c.Lock()
 	c.register[s.Name] = h
+	c.lastChecked[s.Name] = time.Now()
 	c.Unlock()
 
 	// if the TTL is 0 we don't mess with the checks
@@ -265,9 +288,9 @@ func (c *consulRegistry) GetService(name string) ([]*Service, error) {
 
 	// if we're connect enabled only get connect services
 	if c.connect {
-		rsp, _, err = c.Client.Health().Connect(name, "", false, nil)
+		rsp, _, err = c.Client.Health().Connect(name, "", false, c.queryOptions)
 	} else {
-		rsp, _, err = c.Client.Health().Service(name, "", false, nil)
+		rsp, _, err = c.Client.Health().Service(name, "", false, c.queryOptions)
 	}
 	if err != nil {
 		return nil, err
@@ -336,7 +359,7 @@ func (c *consulRegistry) GetService(name string) ([]*Service, error) {
 }
 
 func (c *consulRegistry) ListServices() ([]*Service, error) {
-	rsp, _, err := c.Client.Catalog().Services(nil)
+	rsp, _, err := c.Client.Catalog().Services(c.queryOptions)
 	if err != nil {
 		return nil, err
 	}

registry/consul_registry_test.go

@@ -7,6 +7,7 @@ import (
 	"net"
 	"net/http"
 	"testing"
+	"time"
 
 	consul "github.com/hashicorp/consul/api"
 )
@@ -53,9 +54,14 @@ func newConsulTestRegistry(r *mockRegistry) (*consulRegistry, func()) {
 	go newMockServer(r, l)
 
 	return &consulRegistry{
-			Address:  cfg.Address,
-			Client:   cl,
-			register: make(map[string]uint64),
+			Address:     cfg.Address,
+			Client:      cl,
+			opts:        Options{},
+			register:    make(map[string]uint64),
+			lastChecked: make(map[string]time.Time),
+			queryOptions: &consul.QueryOptions{
+				AllowStale: true,
+			},
 		}, func() {
 			l.Close()
 		}

registry/gossip/README.md

@@ -0,0 +1,24 @@
+# Gossip Registry
+
+Gossip is a zero dependency registry which uses hashicorp/memberlist to broadcast registry information 
+via the SWIM protocol. 
+
+## Usage
+
+Start with the registry flag or env var
+
+```bash
+MICRO_REGISTRY=gossip go run service.go
+```
+
+On startup you'll see something like
+
+```bash
+2018/12/06 18:17:48 Registry Listening on 192.168.1.65:56390
+```
+
+To join this gossip ring set the registry address using flag or env var
+
+```bash
+MICRO_REGISTRY_ADDRESS= 192.168.1.65:56390 
+```

registry/gossip/gossip.go

@@ -0,0 +1,594 @@
+// Package Gossip provides a gossip registry based on hashicorp/memberlist
+package gossip
+
+import (
+	"context"
+	"encoding/json"
+	"io/ioutil"
+	"net"
+	"os"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/google/uuid"
+	"github.com/hashicorp/memberlist"
+	log "github.com/micro/go-log"
+	"github.com/micro/go-micro/registry"
+	pb "github.com/micro/go-micro/registry/gossip/proto"
+	"github.com/mitchellh/hashstructure"
+)
+
+const (
+	addAction  = "update"
+	delAction  = "delete"
+	syncAction = "sync"
+)
+
+type broadcast struct {
+	update *pb.Update
+	notify chan<- struct{}
+}
+
+type delegate struct {
+	queue   *memberlist.TransmitLimitedQueue
+	updates chan *update
+}
+
+type gossipRegistry struct {
+	queue    *memberlist.TransmitLimitedQueue
+	updates  chan *update
+	options  registry.Options
+	member   *memberlist.Memberlist
+	interval time.Duration
+
+	sync.RWMutex
+	services map[string][]*registry.Service
+
+	s        sync.RWMutex
+	watchers map[string]chan *registry.Result
+}
+
+type update struct {
+	Update  *pb.Update
+	Service *registry.Service
+	sync    chan *registry.Service
+}
+
+var (
+	// You should change this if using secure
+	DefaultSecret = []byte("micro-gossip-key") // exactly 16 bytes
+	ExpiryTick    = time.Second * 5
+)
+
+func configure(g *gossipRegistry, opts ...registry.Option) error {
+	// loop through address list and get valid entries
+	addrs := func(curAddrs []string) []string {
+		var newAddrs []string
+		for _, addr := range curAddrs {
+			if trimAddr := strings.TrimSpace(addr); len(trimAddr) > 0 {
+				newAddrs = append(newAddrs, trimAddr)
+			}
+		}
+		return newAddrs
+	}
+
+	// current address list
+	curAddrs := addrs(g.options.Addrs)
+
+	// parse options
+	for _, o := range opts {
+		o(&g.options)
+	}
+
+	// new address list
+	newAddrs := addrs(g.options.Addrs)
+
+	// no new nodes and existing member. no configure
+	if (len(newAddrs) == len(curAddrs)) && g.member != nil {
+		return nil
+	}
+
+	// shutdown old member
+	if g.member != nil {
+		g.member.Shutdown()
+	}
+
+	// replace addresses
+	curAddrs = newAddrs
+
+	// create a queue
+	queue := &memberlist.TransmitLimitedQueue{
+		NumNodes: func() int {
+			return len(curAddrs)
+		},
+		RetransmitMult: 3,
+	}
+
+	// create a new default config
+	c := memberlist.DefaultLocalConfig()
+
+	if optConfig, ok := g.options.Context.Value(contextConfig{}).(*memberlist.Config); ok && optConfig != nil {
+		c = optConfig
+	}
+
+	if hostport, ok := g.options.Context.Value(contextAddress{}).(string); ok {
+		host, port, err := net.SplitHostPort(hostport)
+		if err == nil {
+			pn, err := strconv.Atoi(port)
+			if err == nil {
+				c.BindPort = pn
+			}
+			c.BindAddr = host
+		}
+	} else {
+		// set bind to random port
+		c.BindPort = 0
+	}
+
+	if hostport, ok := g.options.Context.Value(contextAdvertise{}).(string); ok {
+		host, port, err := net.SplitHostPort(hostport)
+		if err == nil {
+			pn, err := strconv.Atoi(port)
+			if err == nil {
+				c.AdvertisePort = pn
+			}
+			c.AdvertiseAddr = host
+		}
+	}
+
+	// machine hostname
+	hostname, _ := os.Hostname()
+
+	// set the name
+	c.Name = strings.Join([]string{"micro", hostname, uuid.New().String()}, "-")
+
+	// set the delegate
+	c.Delegate = &delegate{
+		updates: g.updates,
+		queue:   queue,
+	}
+
+	// log to dev null
+	c.LogOutput = ioutil.Discard
+
+	// set a secret key if secure
+	if g.options.Secure {
+		k, ok := g.options.Context.Value(contextSecretKey{}).([]byte)
+		if !ok {
+			// use the default secret
+			k = DefaultSecret
+		}
+		c.SecretKey = k
+	}
+
+	// create the memberlist
+	m, err := memberlist.Create(c)
+	if err != nil {
+		return err
+	}
+
+	// join the memberlist
+	if len(curAddrs) > 0 {
+		_, err := m.Join(curAddrs)
+		if err != nil {
+			return err
+		}
+	}
+
+	// set internals
+	g.queue = queue
+	g.member = m
+	g.interval = c.GossipInterval
+
+	log.Logf("Registry Listening on %s", m.LocalNode().Address())
+	return nil
+}
+
+func (b *broadcast) Invalidates(other memberlist.Broadcast) bool {
+	up := new(pb.Update)
+	if err := proto.Unmarshal(other.Message(), up); err != nil {
+		return false
+	}
+
+	// ids do not match
+	if b.update.Id == up.Id {
+		return false
+	}
+
+	// timestamps do not match
+	if b.update.Timestamp != up.Timestamp {
+		return false
+	}
+
+	// type does not match
+	if b.update.Type != up.Type {
+		return false
+	}
+
+	// invalidates
+	return true
+}
+
+func (b *broadcast) Message() []byte {
+	up, err := proto.Marshal(b.update)
+	if err != nil {
+		return nil
+	}
+	return up
+}
+
+func (b *broadcast) Finished() {
+	if b.notify != nil {
+		close(b.notify)
+	}
+}
+
+func (d *delegate) NodeMeta(limit int) []byte {
+	return []byte{}
+}
+
+func (d *delegate) NotifyMsg(b []byte) {
+	if len(b) == 0 {
+		return
+	}
+
+	go func() {
+		up := new(pb.Update)
+		if err := proto.Unmarshal(b, up); err != nil {
+			return
+		}
+
+		// only process service action
+		if up.Type != "service" {
+			return
+		}
+
+		var service *registry.Service
+
+		switch up.Metadata["Content-Type"] {
+		case "application/json":
+			if err := json.Unmarshal(up.Data, &service); err != nil {
+				return
+			}
+		// no other content type
+		default:
+			return
+		}
+
+		// send update
+		d.updates <- &update{
+			Update:  up,
+			Service: service,
+		}
+	}()
+}
+
+func (d *delegate) GetBroadcasts(overhead, limit int) [][]byte {
+	return d.queue.GetBroadcasts(overhead, limit)
+}
+
+func (d *delegate) LocalState(join bool) []byte {
+	if !join {
+		return []byte{}
+	}
+
+	syncCh := make(chan *registry.Service, 1)
+	services := map[string][]*registry.Service{}
+
+	d.updates <- &update{
+		Update: &pb.Update{
+			Action: syncAction,
+		},
+		sync: syncCh,
+	}
+
+	for srv := range syncCh {
+		services[srv.Name] = append(services[srv.Name], srv)
+	}
+
+	b, _ := json.Marshal(services)
+	return b
+}
+
+func (d *delegate) MergeRemoteState(buf []byte, join bool) {
+	if len(buf) == 0 {
+		return
+	}
+	if !join {
+		return
+	}
+
+	var services map[string][]*registry.Service
+	if err := json.Unmarshal(buf, &services); err != nil {
+		return
+	}
+
+	for _, service := range services {
+		for _, srv := range service {
+			d.updates <- &update{
+				Update:  &pb.Update{Action: addAction},
+				Service: srv,
+				sync:    nil,
+			}
+		}
+	}
+}
+
+func (g *gossipRegistry) publish(action string, services []*registry.Service) {
+	g.s.RLock()
+	for _, sub := range g.watchers {
+		go func(sub chan *registry.Result) {
+			for _, service := range services {
+				sub <- &registry.Result{Action: action, Service: service}
+			}
+		}(sub)
+	}
+	g.s.RUnlock()
+}
+
+func (g *gossipRegistry) subscribe() (chan *registry.Result, chan bool) {
+	next := make(chan *registry.Result, 10)
+	exit := make(chan bool)
+
+	id := uuid.New().String()
+
+	g.s.Lock()
+	g.watchers[id] = next
+	g.s.Unlock()
+
+	go func() {
+		<-exit
+		g.s.Lock()
+		delete(g.watchers, id)
+		close(next)
+		g.s.Unlock()
+	}()
+
+	return next, exit
+}
+
+func (g *gossipRegistry) run() {
+	var mtx sync.Mutex
+	updates := map[uint64]*update{}
+
+	// expiry loop
+	go func() {
+		t := time.NewTicker(ExpiryTick)
+		defer t.Stop()
+
+		for _ = range t.C {
+			now := uint64(time.Now().UnixNano())
+
+			mtx.Lock()
+
+			// process all the updates
+			for k, v := range updates {
+				// check if expiry time has passed
+				if d := (v.Update.Timestamp + v.Update.Expires); d < now {
+					// delete from records
+					delete(updates, k)
+					// set to delete
+					v.Update.Action = delAction
+					// fire a new update
+					g.updates <- v
+				}
+			}
+
+			mtx.Unlock()
+		}
+	}()
+
+	// process the updates
+	for u := range g.updates {
+		switch u.Update.Action {
+		case addAction:
+			g.Lock()
+			if service, ok := g.services[u.Service.Name]; !ok {
+				g.services[u.Service.Name] = []*registry.Service{u.Service}
+
+			} else {
+				g.services[u.Service.Name] = addServices(service, []*registry.Service{u.Service})
+			}
+			g.Unlock()
+
+			// publish update to watchers
+			go g.publish(addAction, []*registry.Service{u.Service})
+
+			// we need to expire the node at some point in the future
+			if u.Update.Expires > 0 {
+				// create a hash of this service
+				if hash, err := hashstructure.Hash(u.Service, nil); err == nil {
+					mtx.Lock()
+					updates[hash] = u
+					mtx.Unlock()
+				}
+			}
+		case delAction:
+			g.Lock()
+			if service, ok := g.services[u.Service.Name]; ok {
+				if services := delServices(service, []*registry.Service{u.Service}); len(services) == 0 {
+					delete(g.services, u.Service.Name)
+				} else {
+					g.services[u.Service.Name] = services
+				}
+			}
+			g.Unlock()
+
+			// publish update to watchers
+			go g.publish(delAction, []*registry.Service{u.Service})
+
+			// delete from expiry checks
+			if hash, err := hashstructure.Hash(u.Service, nil); err == nil {
+				mtx.Lock()
+				delete(updates, hash)
+				mtx.Unlock()
+			}
+		case syncAction:
+			// no sync channel provided
+			if u.sync == nil {
+				continue
+			}
+
+			g.RLock()
+
+			// push all services through the sync chan
+			for _, service := range g.services {
+				for _, srv := range service {
+					u.sync <- srv
+				}
+
+				// publish to watchers
+				go g.publish(addAction, service)
+			}
+
+			g.RUnlock()
+
+			// close the sync chan
+			close(u.sync)
+		}
+	}
+}
+
+func (g *gossipRegistry) Init(opts ...registry.Option) error {
+	return configure(g, opts...)
+}
+
+func (g *gossipRegistry) Options() registry.Options {
+	return g.options
+}
+
+func (g *gossipRegistry) Register(s *registry.Service, opts ...registry.RegisterOption) error {
+	b, err := json.Marshal(s)
+	if err != nil {
+		return err
+	}
+
+	g.Lock()
+	if service, ok := g.services[s.Name]; !ok {
+		g.services[s.Name] = []*registry.Service{s}
+	} else {
+		g.services[s.Name] = addServices(service, []*registry.Service{s})
+	}
+	g.Unlock()
+
+	var options registry.RegisterOptions
+	for _, o := range opts {
+		o(&options)
+	}
+
+	up := &pb.Update{
+		Id:        uuid.New().String(),
+		Timestamp: uint64(time.Now().UnixNano()),
+		Expires:   uint64(options.TTL.Nanoseconds()),
+		Action:    "update",
+		Type:      "service",
+		Metadata: map[string]string{
+			"Content-Type": "application/json",
+		},
+		Data: b,
+	}
+
+	g.queue.QueueBroadcast(&broadcast{
+		update: up,
+		notify: nil,
+	})
+
+	// wait
+	<-time.After(g.interval * 2)
+
+	return nil
+}
+
+func (g *gossipRegistry) Deregister(s *registry.Service) error {
+	b, err := json.Marshal(s)
+	if err != nil {
+		return err
+	}
+
+	g.Lock()
+	if service, ok := g.services[s.Name]; ok {
+		if services := delServices(service, []*registry.Service{s}); len(services) == 0 {
+			delete(g.services, s.Name)
+		} else {
+			g.services[s.Name] = services
+		}
+	}
+	g.Unlock()
+
+	up := &pb.Update{
+		Id:        uuid.New().String(),
+		Timestamp: uint64(time.Now().UnixNano()),
+		Action:    "delete",
+		Type:      "service",
+		Metadata: map[string]string{
+			"Content-Type": "application/json",
+		},
+		Data: b,
+	}
+
+	g.queue.QueueBroadcast(&broadcast{
+		update: up,
+		notify: nil,
+	})
+
+	// wait
+	<-time.After(g.interval * 2)
+
+	return nil
+}
+
+func (g *gossipRegistry) GetService(name string) ([]*registry.Service, error) {
+	g.RLock()
+	service, ok := g.services[name]
+	g.RUnlock()
+	if !ok {
+		return nil, registry.ErrNotFound
+	}
+	return service, nil
+}
+
+func (g *gossipRegistry) ListServices() ([]*registry.Service, error) {
+	var services []*registry.Service
+	g.RLock()
+	for _, service := range g.services {
+		services = append(services, service...)
+	}
+	g.RUnlock()
+	return services, nil
+}
+
+func (g *gossipRegistry) Watch(opts ...registry.WatchOption) (registry.Watcher, error) {
+	n, e := g.subscribe()
+	return newGossipWatcher(n, e, opts...)
+}
+
+func (g *gossipRegistry) String() string {
+	return "gossip"
+}
+
+func NewRegistry(opts ...registry.Option) registry.Registry {
+	gossip := &gossipRegistry{
+		options: registry.Options{
+			Context: context.Background(),
+		},
+		updates:  make(chan *update, 100),
+		services: make(map[string][]*registry.Service),
+		watchers: make(map[string]chan *registry.Result),
+	}
+
+	// run the updater
+	go gossip.run()
+
+	// configure the gossiper
+	if err := configure(gossip, opts...); err != nil {
+		log.Fatalf("Error configuring registry: %v", err)
+	}
+
+	// wait for setup
+	<-time.After(gossip.interval * 2)
+
+	return gossip
+}

registry/gossip/options.go

@@ -0,0 +1,45 @@
+package gossip
+
+import (
+	"context"
+
+	"github.com/hashicorp/memberlist"
+	"github.com/micro/go-micro/registry"
+)
+
+type contextSecretKey struct{}
+
+// Secret specifies an encryption key. The value should be either
+// 16, 24, or 32 bytes to select AES-128, AES-192, or AES-256.
+func Secret(k []byte) registry.Option {
+	return func(o *registry.Options) {
+		o.Context = context.WithValue(o.Context, contextSecretKey{}, k)
+	}
+}
+
+type contextAddress struct{}
+
+// Address to bind to - host:port
+func Address(a string) registry.Option {
+	return func(o *registry.Options) {
+		o.Context = context.WithValue(o.Context, contextAddress{}, a)
+	}
+}
+
+type contextConfig struct{}
+
+// Config allow to inject a *memberlist.Config struct for configuring gossip
+func Config(c *memberlist.Config) registry.Option {
+	return func(o *registry.Options) {
+		o.Context = context.WithValue(o.Context, contextConfig{}, c)
+	}
+}
+
+type contextAdvertise struct{}
+
+// The address to advertise for other gossip members - host:port
+func Advertise(a string) registry.Option {
+	return func(o *registry.Options) {
+		o.Context = context.WithValue(o.Context, contextAdvertise{}, a)
+	}
+}

registry/gossip/proto/gossip.micro.go

@@ -0,0 +1,28 @@
+// Code generated by protoc-gen-micro. DO NOT EDIT.
+// source: github.com/micro/go-micro/registry/gossip/proto/gossip.proto
+
+/*
+Package gossip is a generated protocol buffer package.
+
+It is generated from these files:
+	github.com/micro/go-micro/registry/gossip/proto/gossip.proto
+
+It has these top-level messages:
+	Update
+*/
+package gossip
+
+import proto "github.com/golang/protobuf/proto"
+import fmt "fmt"
+import 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.ProtoPackageIsVersion2 // please upgrade the proto package

registry/gossip/proto/gossip.pb.go

@@ -0,0 +1,142 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// source: github.com/micro/go-micro/registry/gossip/proto/gossip.proto
+
+package gossip
+
+import proto "github.com/golang/protobuf/proto"
+import fmt "fmt"
+import 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.ProtoPackageIsVersion2 // please upgrade the proto package
+
+// Update is the message broadcast
+type Update struct {
+	// unique id of update
+	Id string `protobuf:"bytes,1,opt,name=id,proto3" json:"id,omitempty"`
+	// unix nano timestamp of update
+	Timestamp uint64 `protobuf:"varint,2,opt,name=timestamp,proto3" json:"timestamp,omitempty"`
+	// time to live for entry
+	Expires uint64 `protobuf:"varint,3,opt,name=expires,proto3" json:"expires,omitempty"`
+	// type of update; service
+	Type string `protobuf:"bytes,4,opt,name=type,proto3" json:"type,omitempty"`
+	// what action is taken; add, del, put
+	Action string `protobuf:"bytes,5,opt,name=action,proto3" json:"action,omitempty"`
+	// any other associated metadata about the data
+	Metadata map[string]string `protobuf:"bytes,6,rep,name=metadata,proto3" json:"metadata,omitempty" protobuf_key:"bytes,1,opt,name=key,proto3" protobuf_val:"bytes,2,opt,name=value,proto3"`
+	// the payload data;
+	Data                 []byte   `protobuf:"bytes,7,opt,name=data,proto3" json:"data,omitempty"`
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *Update) Reset()         { *m = Update{} }
+func (m *Update) String() string { return proto.CompactTextString(m) }
+func (*Update) ProtoMessage()    {}
+func (*Update) Descriptor() ([]byte, []int) {
+	return fileDescriptor_gossip_fd1eb378131a5d12, []int{0}
+}
+func (m *Update) XXX_Unmarshal(b []byte) error {
+	return xxx_messageInfo_Update.Unmarshal(m, b)
+}
+func (m *Update) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	return xxx_messageInfo_Update.Marshal(b, m, deterministic)
+}
+func (dst *Update) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Update.Merge(dst, src)
+}
+func (m *Update) XXX_Size() int {
+	return xxx_messageInfo_Update.Size(m)
+}
+func (m *Update) XXX_DiscardUnknown() {
+	xxx_messageInfo_Update.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_Update proto.InternalMessageInfo
+
+func (m *Update) GetId() string {
+	if m != nil {
+		return m.Id
+	}
+	return ""
+}
+
+func (m *Update) GetTimestamp() uint64 {
+	if m != nil {
+		return m.Timestamp
+	}
+	return 0
+}
+
+func (m *Update) GetExpires() uint64 {
+	if m != nil {
+		return m.Expires
+	}
+	return 0
+}
+
+func (m *Update) GetType() string {
+	if m != nil {
+		return m.Type
+	}
+	return ""
+}
+
+func (m *Update) GetAction() string {
+	if m != nil {
+		return m.Action
+	}
+	return ""
+}
+
+func (m *Update) GetMetadata() map[string]string {
+	if m != nil {
+		return m.Metadata
+	}
+	return nil
+}
+
+func (m *Update) GetData() []byte {
+	if m != nil {
+		return m.Data
+	}
+	return nil
+}
+
+func init() {
+	proto.RegisterType((*Update)(nil), "gossip.Update")
+	proto.RegisterMapType((map[string]string)(nil), "gossip.Update.MetadataEntry")
+}
+
+func init() {
+	proto.RegisterFile("github.com/micro/go-micro/registry/gossip/proto/gossip.proto", fileDescriptor_gossip_fd1eb378131a5d12)
+}
+
+var fileDescriptor_gossip_fd1eb378131a5d12 = []byte{
+	// 251 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x54, 0x90, 0xcf, 0x4a, 0xc4, 0x30,
+	0x10, 0x87, 0x69, 0xb6, 0x9b, 0xb5, 0xe3, 0x1f, 0x64, 0x10, 0x09, 0xb2, 0x87, 0xe2, 0xa9, 0x17,
+	0x5b, 0xd0, 0xcb, 0xa2, 0x5e, 0x3d, 0x7a, 0x09, 0xf8, 0x00, 0xd9, 0x36, 0xd4, 0xa0, 0xd9, 0x84,
+	0x64, 0x56, 0xec, 0x13, 0xf8, 0xda, 0xb2, 0x69, 0x54, 0xbc, 0x7d, 0xdf, 0xcc, 0x24, 0x99, 0x5f,
+	0xe0, 0x71, 0x34, 0xf4, 0xba, 0xdf, 0xb6, 0xbd, 0xb3, 0x9d, 0x35, 0x7d, 0x70, 0xdd, 0xe8, 0x6e,
+	0x66, 0x08, 0x7a, 0x34, 0x91, 0xc2, 0xd4, 0x8d, 0x2e, 0x46, 0xe3, 0x3b, 0x1f, 0x1c, 0xb9, 0x2c,
+	0x6d, 0x12, 0xe4, 0xb3, 0x5d, 0x7f, 0x31, 0xe0, 0x2f, 0x7e, 0x50, 0xa4, 0xf1, 0x0c, 0x98, 0x19,
+	0x44, 0x51, 0x17, 0x4d, 0x25, 0x99, 0x19, 0x70, 0x0d, 0x15, 0x19, 0xab, 0x23, 0x29, 0xeb, 0x05,
+	0xab, 0x8b, 0xa6, 0x94, 0x7f, 0x05, 0x14, 0xb0, 0xd2, 0x9f, 0xde, 0x04, 0x1d, 0xc5, 0x22, 0xf5,
+	0x7e, 0x14, 0x11, 0x4a, 0x9a, 0xbc, 0x16, 0x65, 0xba, 0x29, 0x31, 0x5e, 0x02, 0x57, 0x3d, 0x19,
+	0xb7, 0x13, 0xcb, 0x54, 0xcd, 0x86, 0x1b, 0x38, 0xb2, 0x9a, 0xd4, 0xa0, 0x48, 0x09, 0x5e, 0x2f,
+	0x9a, 0xe3, 0xdb, 0x75, 0x9b, 0xf7, 0x9c, 0xb7, 0x6a, 0x9f, 0x73, 0xfb, 0x69, 0x47, 0x61, 0x92,
+	0xbf, 0xd3, 0x87, 0x57, 0xd2, 0xa9, 0x55, 0x5d, 0x34, 0x27, 0x32, 0xf1, 0xd5, 0x03, 0x9c, 0xfe,
+	0x1b, 0xc7, 0x73, 0x58, 0xbc, 0xe9, 0x29, 0x67, 0x3a, 0x20, 0x5e, 0xc0, 0xf2, 0x43, 0xbd, 0xef,
+	0x75, 0x0a, 0x54, 0xc9, 0x59, 0xee, 0xd9, 0xa6, 0xd8, 0xf2, 0xf4, 0x31, 0x77, 0xdf, 0x01, 0x00,
+	0x00, 0xff, 0xff, 0x06, 0x6e, 0x00, 0x3c, 0x58, 0x01, 0x00, 0x00,
+}

registry/gossip/proto/gossip.proto

@@ -0,0 +1,21 @@
+syntax = "proto3";
+
+package gossip;
+
+// Update is the message broadcast
+message Update {
+	// unique id of update
+	string id = 1;
+	// unix nano timestamp of update
+	uint64 timestamp = 2;
+	// time to live for entry
+	uint64 expires = 3;
+	// type of update; service
+	string type = 4;
+	// what action is taken; add, del, put
+	string action = 5;
+	// any other associated metadata about the data
+	map<string, string> metadata = 6;
+	// the payload data;
+	bytes data = 7;
+}

registry/gossip/util.go

@@ -0,0 +1,132 @@
+package gossip
+
+import (
+	"github.com/micro/go-micro/registry"
+)
+
+func cp(current []*registry.Service) []*registry.Service {
+	var services []*registry.Service
+
+	for _, service := range current {
+		// copy service
+		s := new(registry.Service)
+		*s = *service
+
+		// copy nodes
+		var nodes []*registry.Node
+		for _, node := range service.Nodes {
+			n := new(registry.Node)
+			*n = *node
+			nodes = append(nodes, n)
+		}
+		s.Nodes = nodes
+
+		// copy endpoints
+		var eps []*registry.Endpoint
+		for _, ep := range service.Endpoints {
+			e := new(registry.Endpoint)
+			*e = *ep
+			eps = append(eps, e)
+		}
+		s.Endpoints = eps
+
+		// append service
+		services = append(services, s)
+	}
+
+	return services
+}
+
+func addNodes(old, neu []*registry.Node) []*registry.Node {
+	var nodes []*registry.Node
+
+	// add all new nodes
+	for _, n := range neu {
+		node := *n
+		nodes = append(nodes, &node)
+	}
+
+	// look at old nodes
+	for _, o := range old {
+		var exists bool
+
+		// check against new nodes
+		for _, n := range nodes {
+			// ids match then skip
+			if o.Id == n.Id {
+				exists = true
+				break
+			}
+		}
+
+		// keep old node
+		if !exists {
+			node := *o
+			nodes = append(nodes, &node)
+		}
+	}
+
+	return nodes
+}
+
+func addServices(old, neu []*registry.Service) []*registry.Service {
+	for _, s := range neu {
+		var seen bool
+		for i, o := range old {
+			if o.Version == s.Version {
+				s.Nodes = addNodes(o.Nodes, s.Nodes)
+				seen = true
+				old[i] = s
+				break
+			}
+		}
+		if !seen {
+			old = append(old, s)
+		}
+	}
+	return old
+}
+
+func delNodes(old, del []*registry.Node) []*registry.Node {
+	var nodes []*registry.Node
+	for _, o := range old {
+		var rem bool
+		for _, n := range del {
+			if o.Id == n.Id {
+				rem = true
+				break
+			}
+		}
+		if !rem {
+			nodes = append(nodes, o)
+		}
+	}
+	return nodes
+}
+
+func delServices(old, del []*registry.Service) []*registry.Service {
+	var services []*registry.Service
+
+	for _, o := range old {
+		srv := new(registry.Service)
+		*srv = *o
+
+		var rem bool
+
+		for _, s := range del {
+			if srv.Version == s.Version {
+				srv.Nodes = delNodes(srv.Nodes, s.Nodes)
+
+				if len(srv.Nodes) == 0 {
+					rem = true
+				}
+			}
+		}
+
+		if !rem {
+			services = append(services, srv)
+		}
+	}
+
+	return services
+}

registry/gossip/util_test.go

@@ -0,0 +1,78 @@
+package gossip
+
+import (
+	"testing"
+
+	"github.com/micro/go-micro/registry"
+)
+
+func TestDelServices(t *testing.T) {
+	services := []*registry.Service{
+		{
+			Name:    "foo",
+			Version: "1.0.0",
+			Nodes: []*registry.Node{
+				{
+					Id:      "foo-123",
+					Address: "localhost",
+					Port:    9999,
+				},
+			},
+		},
+		{
+			Name:    "foo",
+			Version: "1.0.0",
+			Nodes: []*registry.Node{
+				{
+					Id:      "foo-123",
+					Address: "localhost",
+					Port:    6666,
+				},
+			},
+		},
+	}
+
+	servs := delServices([]*registry.Service{services[0]}, []*registry.Service{services[1]})
+	if i := len(servs); i > 0 {
+		t.Errorf("Expected 0 nodes, got %d: %+v", i, servs)
+	}
+	t.Logf("Services %+v", servs)
+}
+
+func TestDelNodes(t *testing.T) {
+	services := []*registry.Service{
+		{
+			Name:    "foo",
+			Version: "1.0.0",
+			Nodes: []*registry.Node{
+				{
+					Id:      "foo-123",
+					Address: "localhost",
+					Port:    9999,
+				},
+				{
+					Id:      "foo-321",
+					Address: "localhost",
+					Port:    6666,
+				},
+			},
+		},
+		{
+			Name:    "foo",
+			Version: "1.0.0",
+			Nodes: []*registry.Node{
+				{
+					Id:      "foo-123",
+					Address: "localhost",
+					Port:    6666,
+				},
+			},
+		},
+	}
+
+	nodes := delNodes(services[0].Nodes, services[1].Nodes)
+	if i := len(nodes); i != 1 {
+		t.Errorf("Expected only 1 node, got %d: %+v", i, nodes)
+	}
+	t.Logf("Nodes %+v", nodes)
+}

registry/gossip/watcher.go

@@ -0,0 +1,51 @@
+package gossip
+
+import (
+	"github.com/micro/go-micro/registry"
+)
+
+type gossipWatcher struct {
+	wo   registry.WatchOptions
+	next chan *registry.Result
+	stop chan bool
+}
+
+func newGossipWatcher(ch chan *registry.Result, stop chan bool, opts ...registry.WatchOption) (registry.Watcher, error) {
+	var wo registry.WatchOptions
+	for _, o := range opts {
+		o(&wo)
+	}
+
+	return &gossipWatcher{
+		wo:   wo,
+		next: ch,
+		stop: stop,
+	}, nil
+}
+
+func (m *gossipWatcher) Next() (*registry.Result, error) {
+	for {
+		select {
+		case r, ok := <-m.next:
+			if !ok {
+				return nil, registry.ErrWatcherStopped
+			}
+			// check watch options
+			if len(m.wo.Service) > 0 && r.Service.Name != m.wo.Service {
+				continue
+			}
+			return r, nil
+		case <-m.stop:
+			return nil, registry.ErrWatcherStopped
+		}
+	}
+}
+
+func (m *gossipWatcher) Stop() {
+	select {
+	case <-m.stop:
+		return
+	default:
+		close(m.stop)
+	}
+}

registry/mdns/mdns.go

@@ -1,3 +1,4 @@
+// Package mdns is a multicast dns registry
 package mdns
 
 /*

registry/mock/mock.go

@@ -1,10 +1,14 @@
+// Package mock provides a mock registry for testing
 package mock
 
 import (
+	"sync"
+
 	"github.com/micro/go-micro/registry"
 )
 
 type mockRegistry struct {
+	sync.RWMutex
 	Services map[string][]*registry.Service
 }
 
@@ -54,11 +58,17 @@ var (
 )
 
 func (m *mockRegistry) init() {
+	m.Lock()
+	defer m.Unlock()
+
 	// add some mock data
 	m.Services = mockData
 }
 
 func (m *mockRegistry) GetService(service string) ([]*registry.Service, error) {
+	m.Lock()
+	defer m.Unlock()
+
 	s, ok := m.Services[service]
 	if !ok || len(s) == 0 {
 		return nil, registry.ErrNotFound
@@ -68,6 +78,9 @@ func (m *mockRegistry) GetService(service string) ([]*registry.Service, error) {
 }
 
 func (m *mockRegistry) ListServices() ([]*registry.Service, error) {
+	m.Lock()
+	defer m.Unlock()
+
 	var services []*registry.Service
 	for _, service := range m.Services {
 		services = append(services, service...)
@@ -76,12 +89,18 @@ func (m *mockRegistry) ListServices() ([]*registry.Service, error) {
 }
 
 func (m *mockRegistry) Register(s *registry.Service, opts ...registry.RegisterOption) error {
+	m.Lock()
+	defer m.Unlock()
+
 	services := addServices(m.Services[s.Name], []*registry.Service{s})
 	m.Services[s.Name] = services
 	return nil
 }
 
 func (m *mockRegistry) Deregister(s *registry.Service) error {
+	m.Lock()
+	defer m.Unlock()
+
 	services := delServices(m.Services[s.Name], []*registry.Service{s})
 	m.Services[s.Name] = services
 	return nil

registry/registry.go

@@ -28,7 +28,10 @@ type WatchOption func(*WatchOptions)
 var (
 	DefaultRegistry = newConsulRegistry()
 
+	// Not found error when GetService is called
 	ErrNotFound = errors.New("not found")
+	// Watcher stopped error when watcher is stopped
+	ErrWatcherStopped = errors.New("watcher stopped")
 )
 
 func NewRegistry(opts ...Option) Registry {

selector/cache/cache.go

@@ -1,424 +0,0 @@
-// Package cache is a caching selector. It uses the registry watcher.
-package cache
-
-import (
-	"sync"
-	"time"
-
-	"github.com/micro/go-log"
-	"github.com/micro/go-micro/registry"
-	"github.com/micro/go-micro/selector"
-)
-
-type cacheSelector struct {
-	so  selector.Options
-	ttl time.Duration
-
-	// registry cache
-	sync.Mutex
-	cache map[string][]*registry.Service
-	ttls  map[string]time.Time
-
-	watched map[string]bool
-
-	// used to close or reload watcher
-	reload chan bool
-	exit   chan bool
-}
-
-var (
-	DefaultTTL = time.Minute
-)
-
-func (c *cacheSelector) quit() bool {
-	select {
-	case <-c.exit:
-		return true
-	default:
-		return false
-	}
-}
-
-// cp copies a service. Because we're caching handing back pointers would
-// create a race condition, so we do this instead
-// its fast enough
-func (c *cacheSelector) cp(current []*registry.Service) []*registry.Service {
-	var services []*registry.Service
-
-	for _, service := range current {
-		// copy service
-		s := new(registry.Service)
-		*s = *service
-
-		// copy nodes
-		var nodes []*registry.Node
-		for _, node := range service.Nodes {
-			n := new(registry.Node)
-			*n = *node
-			nodes = append(nodes, n)
-		}
-		s.Nodes = nodes
-
-		// copy endpoints
-		var eps []*registry.Endpoint
-		for _, ep := range service.Endpoints {
-			e := new(registry.Endpoint)
-			*e = *ep
-			eps = append(eps, e)
-		}
-		s.Endpoints = eps
-
-		// append service
-		services = append(services, s)
-	}
-
-	return services
-}
-
-func (c *cacheSelector) del(service string) {
-	delete(c.cache, service)
-	delete(c.ttls, service)
-}
-
-func (c *cacheSelector) get(service string) ([]*registry.Service, error) {
-	c.Lock()
-	defer c.Unlock()
-
-	// watch service if not watched
-	if _, ok := c.watched[service]; !ok {
-		go c.run(service)
-		c.watched[service] = true
-	}
-
-	// get does the actual request for a service
-	// it also caches it
-	get := func(service string) ([]*registry.Service, error) {
-		// ask the registry
-		services, err := c.so.Registry.GetService(service)
-		if err != nil {
-			return nil, err
-		}
-
-		// cache results
-		c.set(service, c.cp(services))
-		return services, nil
-	}
-
-	// check the cache first
-	services, ok := c.cache[service]
-
-	// cache miss or no services
-	if !ok || len(services) == 0 {
-		return get(service)
-	}
-
-	// got cache but lets check ttl
-	ttl, kk := c.ttls[service]
-
-	// within ttl so return cache
-	if kk && time.Since(ttl) < c.ttl {
-		return c.cp(services), nil
-	}
-
-	// expired entry so get service
-	services, err := get(service)
-
-	// no error then return error
-	if err == nil {
-		return services, nil
-	}
-
-	// not found error then return
-	if err == registry.ErrNotFound {
-		return nil, selector.ErrNotFound
-	}
-
-	// other error
-
-	// return expired cache as last resort
-	return c.cp(services), nil
-}
-
-func (c *cacheSelector) set(service string, services []*registry.Service) {
-	c.cache[service] = services
-	c.ttls[service] = time.Now().Add(c.ttl)
-}
-
-func (c *cacheSelector) update(res *registry.Result) {
-	if res == nil || res.Service == nil {
-		return
-	}
-
-	c.Lock()
-	defer c.Unlock()
-
-	services, ok := c.cache[res.Service.Name]
-	if !ok {
-		// we're not going to cache anything
-		// unless there was already a lookup
-		return
-	}
-
-	if len(res.Service.Nodes) == 0 {
-		switch res.Action {
-		case "delete":
-			c.del(res.Service.Name)
-		}
-		return
-	}
-
-	// existing service found
-	var service *registry.Service
-	var index int
-	for i, s := range services {
-		if s.Version == res.Service.Version {
-			service = s
-			index = i
-		}
-	}
-
-	switch res.Action {
-	case "create", "update":
-		if service == nil {
-			c.set(res.Service.Name, append(services, res.Service))
-			return
-		}
-
-		// append old nodes to new service
-		for _, cur := range service.Nodes {
-			var seen bool
-			for _, node := range res.Service.Nodes {
-				if cur.Id == node.Id {
-					seen = true
-					break
-				}
-			}
-			if !seen {
-				res.Service.Nodes = append(res.Service.Nodes, cur)
-			}
-		}
-
-		services[index] = res.Service
-		c.set(res.Service.Name, services)
-	case "delete":
-		if service == nil {
-			return
-		}
-
-		var nodes []*registry.Node
-
-		// filter cur nodes to remove the dead one
-		for _, cur := range service.Nodes {
-			var seen bool
-			for _, del := range res.Service.Nodes {
-				if del.Id == cur.Id {
-					seen = true
-					break
-				}
-			}
-			if !seen {
-				nodes = append(nodes, cur)
-			}
-		}
-
-		// still got nodes, save and return
-		if len(nodes) > 0 {
-			service.Nodes = nodes
-			services[index] = service
-			c.set(service.Name, services)
-			return
-		}
-
-		// zero nodes left
-
-		// only have one thing to delete
-		// nuke the thing
-		if len(services) == 1 {
-			c.del(service.Name)
-			return
-		}
-
-		// still have more than 1 service
-		// check the version and keep what we know
-		var srvs []*registry.Service
-		for _, s := range services {
-			if s.Version != service.Version {
-				srvs = append(srvs, s)
-			}
-		}
-
-		// save
-		c.set(service.Name, srvs)
-	}
-}
-
-// run starts the cache watcher loop
-// it creates a new watcher if there's a problem
-// reloads the watcher if Init is called
-// and returns when Close is called
-func (c *cacheSelector) run(name string) {
-	for {
-		// exit early if already dead
-		if c.quit() {
-			return
-		}
-
-		// create new watcher
-		w, err := c.so.Registry.Watch(
-			registry.WatchService(name),
-		)
-		if err != nil {
-			if c.quit() {
-				return
-			}
-			log.Log(err)
-			time.Sleep(time.Second)
-			continue
-		}
-
-		// watch for events
-		if err := c.watch(w); err != nil {
-			if c.quit() {
-				return
-			}
-			log.Log(err)
-			continue
-		}
-	}
-}
-
-// watch loops the next event and calls update
-// it returns if there's an error
-func (c *cacheSelector) watch(w registry.Watcher) error {
-	defer w.Stop()
-
-	// manage this loop
-	go func() {
-		// wait for exit or reload signal
-		select {
-		case <-c.exit:
-		case <-c.reload:
-		}
-
-		// stop the watcher
-		w.Stop()
-	}()
-
-	for {
-		res, err := w.Next()
-		if err != nil {
-			return err
-		}
-		c.update(res)
-	}
-}
-
-func (c *cacheSelector) Init(opts ...selector.Option) error {
-	for _, o := range opts {
-		o(&c.so)
-	}
-
-	// reload the watcher
-	go func() {
-		select {
-		case <-c.exit:
-			return
-		default:
-			c.reload <- true
-		}
-	}()
-
-	return nil
-}
-
-func (c *cacheSelector) Options() selector.Options {
-	return c.so
-}
-
-func (c *cacheSelector) Select(service string, opts ...selector.SelectOption) (selector.Next, error) {
-	sopts := selector.SelectOptions{
-		Strategy: c.so.Strategy,
-	}
-
-	for _, opt := range opts {
-		opt(&sopts)
-	}
-
-	// get the service
-	// try the cache first
-	// if that fails go directly to the registry
-	services, err := c.get(service)
-	if err != nil {
-		return nil, err
-	}
-
-	// apply the filters
-	for _, filter := range sopts.Filters {
-		services = filter(services)
-	}
-
-	// if there's nothing left, return
-	if len(services) == 0 {
-		return nil, selector.ErrNoneAvailable
-	}
-
-	return sopts.Strategy(services), nil
-}
-
-func (c *cacheSelector) Mark(service string, node *registry.Node, err error) {
-}
-
-func (c *cacheSelector) Reset(service string) {
-}
-
-// Close stops the watcher and destroys the cache
-func (c *cacheSelector) Close() error {
-	c.Lock()
-	c.cache = make(map[string][]*registry.Service)
-	c.watched = make(map[string]bool)
-	c.Unlock()
-
-	select {
-	case <-c.exit:
-		return nil
-	default:
-		close(c.exit)
-	}
-	return nil
-}
-
-func (c *cacheSelector) String() string {
-	return "cache"
-}
-
-func NewSelector(opts ...selector.Option) selector.Selector {
-	sopts := selector.Options{
-		Strategy: selector.Random,
-	}
-
-	for _, opt := range opts {
-		opt(&sopts)
-	}
-
-	if sopts.Registry == nil {
-		sopts.Registry = registry.DefaultRegistry
-	}
-
-	ttl := DefaultTTL
-
-	if sopts.Context != nil {
-		if t, ok := sopts.Context.Value(ttlKey{}).(time.Duration); ok {
-			ttl = t
-		}
-	}
-
-	return &cacheSelector{
-		so:      sopts,
-		ttl:     ttl,
-		watched: make(map[string]bool),
-		cache:   make(map[string][]*registry.Service),
-		ttls:    make(map[string]time.Time),
-		reload:  make(chan bool, 1),
-		exit:    make(chan bool),
-	}
-}

selector/cache/cache_test.go

@@ -1,29 +0,0 @@
-package cache
-
-import (
-	"testing"
-
-	"github.com/micro/go-micro/registry/mock"
-	"github.com/micro/go-micro/selector"
-)
-
-func TestCacheSelector(t *testing.T) {
-	counts := map[string]int{}
-
-	cache := NewSelector(selector.Registry(mock.NewRegistry()))
-
-	next, err := cache.Select("foo")
-	if err != nil {
-		t.Errorf("Unexpected error calling cache select: %v", err)
-	}
-
-	for i := 0; i < 100; i++ {
-		node, err := next()
-		if err != nil {
-			t.Errorf("Expected node err, got err: %v", err)
-		}
-		counts[node.Id]++
-	}
-
-	t.Logf("Cache Counts %v", counts)
-}

selector/default.go

@@ -1,27 +1,341 @@
 package selector
 
 import (
+	"sync"
+	"time"
+
+	"github.com/micro/go-log"
 	"github.com/micro/go-micro/registry"
 )
 
-type defaultSelector struct {
-	so Options
+type registrySelector struct {
+	so  Options
+	ttl time.Duration
+
+	// registry cache
+	sync.RWMutex
+	cache map[string][]*registry.Service
+	ttls  map[string]time.Time
+
+	watched map[string]bool
+
+	// used to close or reload watcher
+	reload chan bool
+	exit   chan bool
 }
 
-func (r *defaultSelector) Init(opts ...Option) error {
-	for _, o := range opts {
-		o(&r.so)
+var (
+	DefaultTTL = time.Minute
+)
+
+func (c *registrySelector) quit() bool {
+	select {
+	case <-c.exit:
+		return true
+	default:
+		return false
 	}
+}
+
+// cp copies a service. Because we're caching handing back pointers would
+// create a race condition, so we do this instead
+// its fast enough
+func (c *registrySelector) cp(current []*registry.Service) []*registry.Service {
+	var services []*registry.Service
+
+	for _, service := range current {
+		// copy service
+		s := new(registry.Service)
+		*s = *service
+
+		// copy nodes
+		var nodes []*registry.Node
+		for _, node := range service.Nodes {
+			n := new(registry.Node)
+			*n = *node
+			nodes = append(nodes, n)
+		}
+		s.Nodes = nodes
+
+		// copy endpoints
+		var eps []*registry.Endpoint
+		for _, ep := range service.Endpoints {
+			e := new(registry.Endpoint)
+			*e = *ep
+			eps = append(eps, e)
+		}
+		s.Endpoints = eps
+
+		// append service
+		services = append(services, s)
+	}
+
+	return services
+}
+
+func (c *registrySelector) del(service string) {
+	delete(c.cache, service)
+	delete(c.ttls, service)
+}
+
+func (c *registrySelector) get(service string) ([]*registry.Service, error) {
+	// read lock
+	c.RLock()
+
+	// check the cache first
+	services, ok := c.cache[service]
+	// get cache ttl
+	ttl, kk := c.ttls[service]
+
+	// got services && within ttl so return cache
+	if ok && kk && time.Since(ttl) < c.ttl {
+		// make a copy
+		cp := c.cp(services)
+		// unlock the read
+		c.RUnlock()
+		// return servics
+		return cp, nil
+	}
+
+	// get does the actual request for a service and cache it
+	get := func(service string) ([]*registry.Service, error) {
+		// ask the registry
+		services, err := c.so.Registry.GetService(service)
+		if err != nil {
+			return nil, err
+		}
+
+		// cache results
+		c.Lock()
+		c.set(service, c.cp(services))
+		c.Unlock()
+
+		return services, nil
+	}
+
+	// watch service if not watched
+	if _, ok := c.watched[service]; !ok {
+		go c.run(service)
+	}
+
+	// unlock the read lock
+	c.RUnlock()
+
+	// get and return services
+	return get(service)
+}
+
+func (c *registrySelector) set(service string, services []*registry.Service) {
+	c.cache[service] = services
+	c.ttls[service] = time.Now().Add(c.ttl)
+}
+
+func (c *registrySelector) update(res *registry.Result) {
+	if res == nil || res.Service == nil {
+		return
+	}
+
+	c.Lock()
+	defer c.Unlock()
+
+	services, ok := c.cache[res.Service.Name]
+	if !ok {
+		// we're not going to cache anything
+		// unless there was already a lookup
+		return
+	}
+
+	if len(res.Service.Nodes) == 0 {
+		switch res.Action {
+		case "delete":
+			c.del(res.Service.Name)
+		}
+		return
+	}
+
+	// existing service found
+	var service *registry.Service
+	var index int
+	for i, s := range services {
+		if s.Version == res.Service.Version {
+			service = s
+			index = i
+		}
+	}
+
+	switch res.Action {
+	case "create", "update":
+		if service == nil {
+			c.set(res.Service.Name, append(services, res.Service))
+			return
+		}
+
+		// append old nodes to new service
+		for _, cur := range service.Nodes {
+			var seen bool
+			for _, node := range res.Service.Nodes {
+				if cur.Id == node.Id {
+					seen = true
+					break
+				}
+			}
+			if !seen {
+				res.Service.Nodes = append(res.Service.Nodes, cur)
+			}
+		}
+
+		services[index] = res.Service
+		c.set(res.Service.Name, services)
+	case "delete":
+		if service == nil {
+			return
+		}
+
+		var nodes []*registry.Node
+
+		// filter cur nodes to remove the dead one
+		for _, cur := range service.Nodes {
+			var seen bool
+			for _, del := range res.Service.Nodes {
+				if del.Id == cur.Id {
+					seen = true
+					break
+				}
+			}
+			if !seen {
+				nodes = append(nodes, cur)
+			}
+		}
+
+		// still got nodes, save and return
+		if len(nodes) > 0 {
+			service.Nodes = nodes
+			services[index] = service
+			c.set(service.Name, services)
+			return
+		}
+
+		// zero nodes left
+
+		// only have one thing to delete
+		// nuke the thing
+		if len(services) == 1 {
+			c.del(service.Name)
+			return
+		}
+
+		// still have more than 1 service
+		// check the version and keep what we know
+		var srvs []*registry.Service
+		for _, s := range services {
+			if s.Version != service.Version {
+				srvs = append(srvs, s)
+			}
+		}
+
+		// save
+		c.set(service.Name, srvs)
+	}
+}
+
+// run starts the cache watcher loop
+// it creates a new watcher if there's a problem
+// reloads the watcher if Init is called
+// and returns when Close is called
+func (c *registrySelector) run(name string) {
+	// set watcher
+	c.Lock()
+	c.watched[name] = true
+	c.Unlock()
+
+	// delete watcher on exit
+	defer func() {
+		c.Lock()
+		delete(c.watched, name)
+		c.Unlock()
+	}()
+
+	for {
+		// exit early if already dead
+		if c.quit() {
+			return
+		}
+
+		// create new watcher
+		w, err := c.so.Registry.Watch(
+			registry.WatchService(name),
+		)
+		if err != nil {
+			if c.quit() {
+				return
+			}
+			log.Log(err)
+			time.Sleep(time.Second)
+			continue
+		}
+
+		// watch for events
+		if err := c.watch(w); err != nil {
+			if c.quit() {
+				return
+			}
+			log.Log(err)
+			continue
+		}
+	}
+}
+
+// watch loops the next event and calls update
+// it returns if there's an error
+func (c *registrySelector) watch(w registry.Watcher) error {
+	defer w.Stop()
+
+	// manage this loop
+	go func() {
+		// wait for exit or reload signal
+		select {
+		case <-c.exit:
+		case <-c.reload:
+		}
+
+		// stop the watcher
+		w.Stop()
+	}()
+
+	for {
+		res, err := w.Next()
+		if err != nil {
+			return err
+		}
+		c.update(res)
+	}
+}
+
+func (c *registrySelector) Init(opts ...Option) error {
+	for _, o := range opts {
+		o(&c.so)
+	}
+
+	// reload the watcher
+	go func() {
+		select {
+		case <-c.exit:
+			return
+		default:
+			c.reload <- true
+		}
+	}()
+
 	return nil
 }
 
-func (r *defaultSelector) Options() Options {
-	return r.so
+func (c *registrySelector) Options() Options {
+	return c.so
 }
 
-func (r *defaultSelector) Select(service string, opts ...SelectOption) (Next, error) {
+func (c *registrySelector) Select(service string, opts ...SelectOption) (Next, error) {
 	sopts := SelectOptions{
-		Strategy: r.so.Strategy,
+		Strategy: c.so.Strategy,
 	}
 
 	for _, opt := range opts {
@@ -29,7 +343,9 @@ func (r *defaultSelector) Select(service string, opts ...SelectOption) (Next, er
 	}
 
 	// get the service
-	services, err := r.so.Registry.GetService(service)
+	// try the cache first
+	// if that fails go directly to the registry
+	services, err := c.get(service)
 	if err != nil {
 		return nil, err
 	}
@@ -47,21 +363,33 @@ func (r *defaultSelector) Select(service string, opts ...SelectOption) (Next, er
 	return sopts.Strategy(services), nil
 }
 
-func (r *defaultSelector) Mark(service string, node *registry.Node, err error) {
+func (c *registrySelector) Mark(service string, node *registry.Node, err error) {
 }
 
-func (r *defaultSelector) Reset(service string) {
+func (c *registrySelector) Reset(service string) {
 }
 
-func (r *defaultSelector) Close() error {
+// Close stops the watcher and destroys the cache
+func (c *registrySelector) Close() error {
+	c.Lock()
+	c.cache = make(map[string][]*registry.Service)
+	c.watched = make(map[string]bool)
+	c.Unlock()
+
+	select {
+	case <-c.exit:
+		return nil
+	default:
+		close(c.exit)
+	}
 	return nil
 }
 
-func (r *defaultSelector) String() string {
-	return "default"
+func (c *registrySelector) String() string {
+	return "registry"
 }
 
-func newDefaultSelector(opts ...Option) Selector {
+func NewSelector(opts ...Option) Selector {
 	sopts := Options{
 		Strategy: Random,
 	}
@@ -74,7 +402,21 @@ func newDefaultSelector(opts ...Option) Selector {
 		sopts.Registry = registry.DefaultRegistry
 	}
 
-	return &defaultSelector{
-		so: sopts,
+	ttl := DefaultTTL
+
+	if sopts.Context != nil {
+		if t, ok := sopts.Context.Value("selector_ttl").(time.Duration); ok {
+			ttl = t
+		}
+	}
+
+	return &registrySelector{
+		so:      sopts,
+		ttl:     ttl,
+		watched: make(map[string]bool),
+		cache:   make(map[string][]*registry.Service),
+		ttls:    make(map[string]time.Time),
+		reload:  make(chan bool, 1),
+		exit:    make(chan bool),
 	}
 }

selector/default_test.go

@@ -6,14 +6,14 @@ import (
 	"github.com/micro/go-micro/registry/mock"
 )
 
-func TestDefaultSelector(t *testing.T) {
+func TestRegistrySelector(t *testing.T) {
 	counts := map[string]int{}
 
-	rs := newDefaultSelector(Registry(mock.NewRegistry()))
+	cache := NewSelector(Registry(mock.NewRegistry()))
 
-	next, err := rs.Select("foo")
+	next, err := cache.Select("foo")
 	if err != nil {
-		t.Errorf("Unexpected error calling default select: %v", err)
+		t.Errorf("Unexpected error calling cache select: %v", err)
 	}
 
 	for i := 0; i < 100; i++ {
@@ -24,5 +24,5 @@ func TestDefaultSelector(t *testing.T) {
 		counts[node.Id]++
 	}
 
-	t.Logf("Default Counts %v", counts)
+	t.Logf("Selector Counts %v", counts)
 }

selector/dns/dns.go

@@ -0,0 +1,128 @@
+// Package dns provides a dns SRV selector
+package dns
+
+import (
+	"net"
+	"strconv"
+
+	"github.com/micro/go-micro/registry"
+	"github.com/micro/go-micro/selector"
+)
+
+type dnsSelector struct {
+	options selector.Options
+	domain  string
+}
+
+var (
+	DefaultDomain = "local"
+)
+
+func (d *dnsSelector) Init(opts ...selector.Option) error {
+	for _, o := range opts {
+		o(&d.options)
+	}
+	return nil
+}
+
+func (d *dnsSelector) Options() selector.Options {
+	return d.options
+}
+
+func (d *dnsSelector) Select(service string, opts ...selector.SelectOption) (selector.Next, error) {
+	var srv []*net.SRV
+
+	// check if its host:port
+	host, port, err := net.SplitHostPort(service)
+	// not host:port
+	if err != nil {
+		// lookup the SRV record
+		_, srvs, err := net.LookupSRV(service, "tcp", d.domain)
+		if err != nil {
+			return nil, err
+		}
+		// set SRV records
+		srv = srvs
+		// got host:port
+	} else {
+		p, _ := strconv.Atoi(port)
+
+		// lookup the A record
+		ips, err := net.LookupHost(host)
+		if err != nil {
+			return nil, err
+		}
+
+		// create SRV records
+		for _, ip := range ips {
+			srv = append(srv, &net.SRV{
+				Target: ip,
+				Port:   uint16(p),
+			})
+		}
+	}
+
+	var nodes []*registry.Node
+	for _, node := range srv {
+		nodes = append(nodes, &registry.Node{
+			Id:      node.Target,
+			Address: node.Target,
+			Port:    int(node.Port),
+		})
+	}
+
+	services := []*registry.Service{
+		&registry.Service{
+			Name:  service,
+			Nodes: nodes,
+		},
+	}
+
+	sopts := selector.SelectOptions{
+		Strategy: d.options.Strategy,
+	}
+
+	for _, opt := range opts {
+		opt(&sopts)
+	}
+
+	// apply the filters
+	for _, filter := range sopts.Filters {
+		services = filter(services)
+	}
+
+	// if there's nothing left, return
+	if len(services) == 0 {
+		return nil, selector.ErrNoneAvailable
+	}
+
+	return sopts.Strategy(services), nil
+}
+
+func (d *dnsSelector) Mark(service string, node *registry.Node, err error) {
+	return
+}
+
+func (d *dnsSelector) Reset(service string) {
+	return
+}
+
+func (d *dnsSelector) Close() error {
+	return nil
+}
+
+func (d *dnsSelector) String() string {
+	return "dns"
+}
+
+func NewSelector(opts ...selector.Option) selector.Selector {
+	options := selector.Options{
+		Strategy: selector.Random,
+	}
+
+	for _, o := range opts {
+		o(&options)
+	}
+
+	return &dnsSelector{options: options, domain: DefaultDomain}
+}

selector/registry/options.go

@@ -1,4 +1,4 @@
-package cache
+package registry
 
 import (
 	"context"
@@ -7,14 +7,12 @@ import (
 	"github.com/micro/go-micro/selector"
 )
 
-type ttlKey struct{}
-
-// Set the cache ttl
+// Set the registry cache ttl
 func TTL(t time.Duration) selector.Option {
 	return func(o *selector.Options) {
 		if o.Context == nil {
 			o.Context = context.Background()
 		}
-		o.Context = context.WithValue(o.Context, ttlKey{}, t)
+		o.Context = context.WithValue(o.Context, "selector_ttl", t)
 	}
 }

selector/registry/registry.go

@@ -0,0 +1,11 @@
+// Package registry uses the go-micro registry for selection
+package registry
+
+import (
+	"github.com/micro/go-micro/selector"
+)
+
+// NewSelector returns a new registry selector
+func NewSelector(opts ...selector.Option) selector.Selector {
+	return selector.NewSelector(opts...)
+}

selector/selector.go

@@ -1,4 +1,4 @@
-// Package selector is a way to load balance service nodes
+// Package selector is a way to pick a list of service nodes
 package selector
 
 import (
@@ -35,12 +35,8 @@ type Filter func([]*registry.Service) []*registry.Service
 type Strategy func([]*registry.Service) Next
 
 var (
-	DefaultSelector = newDefaultSelector()
+	DefaultSelector = NewSelector()
 
 	ErrNotFound      = errors.New("not found")
 	ErrNoneAvailable = errors.New("none available")
 )
-
-func NewSelector(opts ...Option) Selector {
-	return newDefaultSelector(opts...)
-}

selector/static/static.go

@@ -0,0 +1,71 @@
+// Package static provides a static resolver which returns the name/ip passed in without any change
+package static
+
+import (
+	"net"
+	"strconv"
+
+	"github.com/micro/go-micro/registry"
+	"github.com/micro/go-micro/selector"
+)
+
+// staticSelector is a static selector
+type staticSelector struct {
+	opts selector.Options
+}
+
+func (s *staticSelector) Init(opts ...selector.Option) error {
+	for _, o := range opts {
+		o(&s.opts)
+	}
+	return nil
+}
+
+func (s *staticSelector) Options() selector.Options {
+	return s.opts
+}
+
+func (s *staticSelector) Select(service string, opts ...selector.SelectOption) (selector.Next, error) {
+	var port int
+	addr, pt, err := net.SplitHostPort(service)
+	if err != nil {
+		addr = service
+		port = 0
+	} else {
+		port, _ = strconv.Atoi(pt)
+	}
+
+	return func() (*registry.Node, error) {
+		return &registry.Node{
+			Id:      service,
+			Address: addr,
+			Port:    port,
+		}, nil
+	}, nil
+}
+
+func (s *staticSelector) Mark(service string, node *registry.Node, err error) {
+	return
+}
+
+func (s *staticSelector) Reset(service string) {
+	return
+}
+
+func (s *staticSelector) Close() error {
+	return nil
+}
+
+func (s *staticSelector) String() string {
+	return "static"
+}
+
+func NewSelector(opts ...selector.Option) selector.Selector {
+	var options selector.Options
+	for _, o := range opts {
+		o(&options)
+	}
+	return &staticSelector{
+		opts: options,
+	}
+}

server/handler.go

@@ -1,37 +1,5 @@
 package server
 
-import (
-	"github.com/micro/go-micro/registry"
-)
-
-// Handler interface represents a Service request handler. It's generated
-// by passing any type of public concrete object with methods into server.NewHandler.
-// Most will pass in a struct.
-//
-// Example:
-//
-//	type Service struct {}
-//
-//	func (s *Service) Method(context, request, response) error {
-//		return nil
-//	}
-//
-type Handler interface {
-	Name() string
-	Handler() interface{}
-	Endpoints() []*registry.Endpoint
-	Options() HandlerOptions
-}
-
-// Subscriber interface represents a subscription to a given topic using
-// a specific subscriber function or object with methods.
-type Subscriber interface {
-	Topic() string
-	Subscriber() interface{}
-	Endpoints() []*registry.Endpoint
-	Options() SubscriberOptions
-}
-
 type HandlerOptions struct {
 	Internal bool
 	Metadata map[string]map[string]string

server/options.go

@@ -25,8 +25,12 @@ type Options struct {
 	HdlrWrappers []HandlerWrapper
 	SubWrappers  []SubscriberWrapper
 
+	// The register expiry time
 	RegisterTTL time.Duration
 
+	// The router for requests
+	Router Router
+
 	// Debug Handler which can be set by a user
 	DebugHandler debug.DebugHandler
 
@@ -164,6 +168,13 @@ func RegisterTTL(t time.Duration) Option {
 	}
 }
 
+// WithRouter sets the request router
+func WithRouter(r Router) Option {
+	return func(o *Options) {
+		o.Router = r
+	}
+}
+
 // Wait tells the server to wait for requests to finish before exiting
 func Wait(b bool) Option {
 	return func(o *Options) {

server/rpc_codec.go

@@ -4,15 +4,20 @@ import (
 	"bytes"
 
 	"github.com/micro/go-micro/codec"
+	raw "github.com/micro/go-micro/codec/bytes"
+	"github.com/micro/go-micro/codec/grpc"
+	"github.com/micro/go-micro/codec/json"
 	"github.com/micro/go-micro/codec/jsonrpc"
+	"github.com/micro/go-micro/codec/proto"
 	"github.com/micro/go-micro/codec/protorpc"
 	"github.com/micro/go-micro/transport"
 	"github.com/pkg/errors"
 )
 
-type rpcPlusCodec struct {
+type rpcCodec struct {
 	socket transport.Socket
 	codec  codec.Codec
+	first  bool
 
 	req *transport.Message
 	buf *readWriteCloser
@@ -24,12 +29,17 @@ type readWriteCloser struct {
 }
 
 var (
-	defaultCodecs = map[string]codec.NewCodec{
-		"application/json":         jsonrpc.NewCodec,
+	DefaultContentType = "application/protobuf"
+
+	DefaultCodecs = map[string]codec.NewCodec{
+		"application/grpc":         grpc.NewCodec,
+		"application/grpc+json":    grpc.NewCodec,
+		"application/grpc+proto":   grpc.NewCodec,
+		"application/json":         json.NewCodec,
 		"application/json-rpc":     jsonrpc.NewCodec,
-		"application/protobuf":     protorpc.NewCodec,
+		"application/protobuf":     proto.NewCodec,
 		"application/proto-rpc":    protorpc.NewCodec,
-		"application/octet-stream": protorpc.NewCodec,
+		"application/octet-stream": raw.NewCodec,
 	}
 )
 
@@ -47,12 +57,13 @@ func (rwc *readWriteCloser) Close() error {
 	return nil
 }
 
-func newRpcPlusCodec(req *transport.Message, socket transport.Socket, c codec.NewCodec) serverCodec {
+func newRpcCodec(req *transport.Message, socket transport.Socket, c codec.NewCodec) codec.Codec {
 	rwc := &readWriteCloser{
 		rbuf: bytes.NewBuffer(req.Body),
 		wbuf: bytes.NewBuffer(nil),
 	}
-	r := &rpcPlusCodec{
+	r := &rpcCodec{
+		first:  true,
 		buf:    rwc,
 		codec:  c(rwc),
 		req:    req,
@@ -61,58 +72,129 @@ func newRpcPlusCodec(req *transport.Message, socket transport.Socket, c codec.Ne
 	return r
 }
 
-func (c *rpcPlusCodec) ReadRequestHeader(r *request, first bool) error {
-	m := codec.Message{Header: c.req.Header}
+func (c *rpcCodec) ReadHeader(r *codec.Message, t codec.MessageType) error {
+	// the initieal message
+	m := codec.Message{
+		Header: c.req.Header,
+		Body:   c.req.Body,
+	}
 
-	if !first {
+	// if its a follow on request read it
+	if !c.first {
 		var tm transport.Message
+
+		// read off the socket
 		if err := c.socket.Recv(&tm); err != nil {
 			return err
 		}
+		// reset the read buffer
 		c.buf.rbuf.Reset()
+
+		// write the body to the buffer
 		if _, err := c.buf.rbuf.Write(tm.Body); err != nil {
 			return err
 		}
 
+		// set the message header
 		m.Header = tm.Header
+		// set the message body
+		m.Body = tm.Body
 	}
 
+	// no longer first read
+	c.first = false
+
+	// set some internal things
+	m.Target = m.Header["X-Micro-Service"]
+	m.Endpoint = m.Header["X-Micro-Endpoint"]
+	m.Id = m.Header["X-Micro-Id"]
+
+	// read header via codec
 	err := c.codec.ReadHeader(&m, codec.Request)
-	r.ServiceMethod = m.Method
-	r.Seq = m.Id
+
+	// set the method/id
+	r.Endpoint = m.Endpoint
+	r.Id = m.Id
+
 	return err
 }
 
-func (c *rpcPlusCodec) ReadRequestBody(b interface{}) error {
+func (c *rpcCodec) ReadBody(b interface{}) error {
 	return c.codec.ReadBody(b)
 }
 
-func (c *rpcPlusCodec) WriteResponse(r *response, body interface{}, last bool) error {
+func (c *rpcCodec) Write(r *codec.Message, b interface{}) error {
 	c.buf.wbuf.Reset()
+
+	// create a new message
 	m := &codec.Message{
-		Method: r.ServiceMethod,
-		Id:     r.Seq,
-		Error:  r.Error,
-		Type:   codec.Response,
-		Header: map[string]string{},
+		Endpoint: r.Endpoint,
+		Id:       r.Id,
+		Error:    r.Error,
+		Type:     r.Type,
+		Header:   map[string]string{},
 	}
-	if err := c.codec.Write(m, body); err != nil {
+
+	// set request id
+	if len(r.Id) > 0 {
+		m.Header["X-Micro-Id"] = r.Id
+	}
+
+	// set target
+	if len(r.Target) > 0 {
+		m.Header["X-Micro-Service"] = r.Target
+	}
+
+	// set request endpoint
+	if len(r.Endpoint) > 0 {
+		m.Header["X-Micro-Endpoint"] = r.Endpoint
+	}
+
+	if len(r.Error) > 0 {
+		m.Header["X-Micro-Error"] = r.Error
+	}
+
+	// the body being sent
+	var body []byte
+
+	// if we have encoded data just send it
+	if len(r.Body) > 0 {
+		body = r.Body
+		// write to the body
+	} else if err := c.codec.Write(m, b); err != nil {
 		c.buf.wbuf.Reset()
+
+		// write an error if it failed
 		m.Error = errors.Wrapf(err, "Unable to encode body").Error()
+		m.Header["X-Micro-Error"] = m.Error
+		// no body to write
 		if err := c.codec.Write(m, nil); err != nil {
 			return err
 		}
+		// write the body
+	} else {
+		// set the body
+		body = c.buf.wbuf.Bytes()
 	}
 
-	m.Header["Content-Type"] = c.req.Header["Content-Type"]
+	// Set content type if theres content
+	if len(body) > 0 {
+		m.Header["Content-Type"] = c.req.Header["Content-Type"]
+	}
+
+	// send on the socket
 	return c.socket.Send(&transport.Message{
 		Header: m.Header,
-		Body:   c.buf.wbuf.Bytes(),
+		Body:   body,
 	})
 }
 
-func (c *rpcPlusCodec) Close() error {
+func (c *rpcCodec) Close() error {
 	c.buf.Close()
 	c.codec.Close()
 	return c.socket.Close()
 }
+
+func (c *rpcCodec) String() string {
+	return "rpc"
+}

server/rpc_codec_test.go

@@ -38,7 +38,7 @@ func TestCodecWriteError(t *testing.T) {
 		wbuf: new(bytes.Buffer),
 	}
 
-	c := rpcPlusCodec{
+	c := rpcCodec{
 		buf: &rwc,
 		codec: &testCodec{
 			buf: rwc.wbuf,
@@ -47,15 +47,14 @@ func TestCodecWriteError(t *testing.T) {
 		socket: socket,
 	}
 
-	err := c.WriteResponse(&response{
-		ServiceMethod: "Service.Method",
-		Seq:           0,
-		Error:         "",
-		next:          nil,
-	}, "body", false)
+	err := c.Write(&codec.Message{
+		Endpoint: "Service.Endpoint",
+		Id:       "0",
+		Error:    "",
+	}, "body")
 
 	if err != nil {
-		t.Fatalf(`Expected WriteResponse to fail; got "%+v" instead`, err)
+		t.Fatalf(`Expected Write to fail; got "%+v" instead`, err)
 	}
 
 	const expectedError = "Unable to encode body: simulating a codec write failure"

server/rpc_request.go

@@ -1,10 +1,18 @@
 package server
 
+import (
+	"github.com/micro/go-micro/codec"
+	"github.com/micro/go-micro/transport"
+)
+
 type rpcRequest struct {
 	service     string
-	method      string
+	endpoint    string
 	contentType string
-	request     interface{}
+	socket      transport.Socket
+	codec       codec.Codec
+	header      map[string]string
+	body        []byte
 	stream      bool
 }
 
@@ -14,6 +22,10 @@ type rpcMessage struct {
 	payload     interface{}
 }
 
+func (r *rpcRequest) Codec() codec.Reader {
+	return r.codec
+}
+
 func (r *rpcRequest) ContentType() string {
 	return r.contentType
 }
@@ -22,12 +34,30 @@ func (r *rpcRequest) Service() string {
 	return r.service
 }
 
-func (r *rpcRequest) Method() string {
-	return r.method
+func (r *rpcRequest) Endpoint() string {
+	return r.endpoint
 }
 
-func (r *rpcRequest) Request() interface{} {
-	return r.request
+func (r *rpcRequest) Header() map[string]string {
+	return r.header
+}
+
+func (r *rpcRequest) Read() ([]byte, error) {
+	// got a body
+	if r.body != nil {
+		b := r.body
+		r.body = nil
+		return b, nil
+	}
+
+	var msg transport.Message
+	err := r.socket.Recv(&msg)
+	if err != nil {
+		return nil, err
+	}
+	r.header = msg.Header
+
+	return msg.Body, nil
 }
 
 func (r *rpcRequest) Stream() bool {

server/rpc_response.go

@@ -0,0 +1,35 @@
+package server
+
+import (
+	"net/http"
+
+	"github.com/micro/go-micro/codec"
+	"github.com/micro/go-micro/transport"
+)
+
+type rpcResponse struct {
+	header map[string]string
+	socket transport.Socket
+	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 {
+	if _, ok := r.header["Content-Type"]; !ok {
+		r.header["Content-Type"] = http.DetectContentType(b)
+	}
+
+	return r.socket.Send(&transport.Message{
+		Header: r.header,
+		Body:   b,
+	})
+}

server/rpc_router.go

@@ -17,6 +17,7 @@ import (
 	"unicode/utf8"
 
 	"github.com/micro/go-log"
+	"github.com/micro/go-micro/codec"
 )
 
 var (
@@ -48,20 +49,17 @@ type service struct {
 }
 
 type request struct {
-	ServiceMethod string   // format: "Service.Method"
-	Seq           uint64   // sequence number chosen by client
-	next          *request // for free list in Server
+	msg  *codec.Message
+	next *request // for free list in Server
 }
 
 type response struct {
-	ServiceMethod string    // echoes that of the Request
-	Seq           uint64    // echoes that of the request
-	Error         string    // error, if any.
-	next          *response // for free list in Server
+	msg  *codec.Message
+	next *response // for free list in Server
 }
 
-// server represents an RPC Server.
-type server struct {
+// router represents an RPC router.
+type router struct {
 	name         string
 	mu           sync.Mutex // protects the serviceMap
 	serviceMap   map[string]*service
@@ -72,6 +70,12 @@ type server struct {
 	hdlrWrappers []HandlerWrapper
 }
 
+func newRpcRouter() *router {
+	return &router{
+		serviceMap: make(map[string]*service),
+	}
+}
+
 // Is this an exported - upper case - name?
 func isExported(name string) bool {
 	rune, _ := utf8.DecodeRuneInString(name)
@@ -158,78 +162,40 @@ func prepareMethod(method reflect.Method) *methodType {
 	return &methodType{method: method, ArgType: argType, ReplyType: replyType, ContextType: contextType, stream: stream}
 }
 
-func (server *server) register(rcvr interface{}) error {
-	server.mu.Lock()
-	defer server.mu.Unlock()
-	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 == "" {
-		log.Fatal("rpc: no service name for type", s.typ.String())
-	}
-	if !isExported(sname) {
-		s := "rpc Register: type " + sname + " is not exported"
-		log.Log(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)
+func (router *router) sendResponse(sending sync.Locker, req *request, reply interface{}, cc codec.Writer, errmsg string, last bool) (err error) {
+	msg := new(codec.Message)
+	msg.Type = codec.Response
+	resp := router.getResponse()
+	resp.msg = msg
 
-	// Install the methods
-	for m := 0; m < s.typ.NumMethod(); m++ {
-		method := s.typ.Method(m)
-		if mt := prepareMethod(method); 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(s)
-		return errors.New(s)
-	}
-	server.serviceMap[s.name] = s
-	return nil
-}
-
-func (server *server) sendResponse(sending sync.Locker, req *request, reply interface{}, codec serverCodec, errmsg string, last bool) (err error) {
-	resp := server.getResponse()
 	// Encode the response header
-	resp.ServiceMethod = req.ServiceMethod
+	resp.msg.Endpoint = req.msg.Endpoint
 	if errmsg != "" {
-		resp.Error = errmsg
+		resp.msg.Error = errmsg
 		reply = invalidRequest
 	}
-	resp.Seq = req.Seq
+	resp.msg.Id = req.msg.Id
 	sending.Lock()
-	err = codec.WriteResponse(resp, reply, last)
+	err = cc.Write(resp.msg, reply)
 	sending.Unlock()
-	server.freeResponse(resp)
+	router.freeResponse(resp)
 	return err
 }
 
-func (s *service) call(ctx context.Context, server *server, sending *sync.Mutex, mtype *methodType, req *request, argv, replyv reflect.Value, codec serverCodec, ct string) {
+func (s *service) call(ctx context.Context, router *router, sending *sync.Mutex, mtype *methodType, req *request, argv, replyv reflect.Value, cc codec.Writer) {
 	function := mtype.method.Func
 	var returnValues []reflect.Value
 
 	r := &rpcRequest{
-		service:     server.name,
-		contentType: ct,
-		method:      req.ServiceMethod,
+		service:     req.msg.Target,
+		contentType: req.msg.Header["Content-Type"],
+		endpoint:    req.msg.Endpoint,
+		body:        req.msg.Body,
 	}
 
 	if !mtype.stream {
-		r.request = argv.Interface()
-
 		fn := func(ctx context.Context, req Request, rsp interface{}) error {
-			returnValues = function.Call([]reflect.Value{s.rcvr, mtype.prepareContext(ctx), reflect.ValueOf(req.Request()), reflect.ValueOf(rsp)})
+			returnValues = function.Call([]reflect.Value{s.rcvr, mtype.prepareContext(ctx), reflect.ValueOf(argv.Interface()), reflect.ValueOf(rsp)})
 
 			// The return value for the method is an error.
 			if err := returnValues[0].Interface(); err != nil {
@@ -239,21 +205,17 @@ func (s *service) call(ctx context.Context, server *server, sending *sync.Mutex,
 			return nil
 		}
 
-		for i := len(server.hdlrWrappers); i > 0; i-- {
-			fn = server.hdlrWrappers[i-1](fn)
-		}
-
 		errmsg := ""
 		err := fn(ctx, r, replyv.Interface())
 		if err != nil {
 			errmsg = err.Error()
 		}
 
-		err = server.sendResponse(sending, req, replyv.Interface(), codec, errmsg, true)
+		err = router.sendResponse(sending, req, replyv.Interface(), cc, errmsg, true)
 		if err != nil {
 			log.Log("rpc call: unable to send response: ", err)
 		}
-		server.freeRequest(req)
+		router.freeRequest(req)
 		return
 	}
 
@@ -264,9 +226,9 @@ func (s *service) call(ctx context.Context, server *server, sending *sync.Mutex,
 
 	stream := &rpcStream{
 		context: ctx,
-		codec:   codec,
+		codec:   cc.(codec.Codec),
 		request: r,
-		seq:     req.Seq,
+		id:      req.msg.Id,
 	}
 
 	// Invoke the method, providing a new value for the reply.
@@ -284,10 +246,6 @@ func (s *service) call(ctx context.Context, server *server, sending *sync.Mutex,
 		}
 	}
 
-	for i := len(server.hdlrWrappers); i > 0; i-- {
-		fn = server.hdlrWrappers[i-1](fn)
-	}
-
 	// client.Stream request
 	r.stream = true
 
@@ -299,8 +257,8 @@ func (s *service) call(ctx context.Context, server *server, sending *sync.Mutex,
 	// this is the last packet, we don't do anything with
 	// the error here (well sendStreamResponse will log it
 	// already)
-	server.sendResponse(sending, req, nil, codec, errmsg, true)
-	server.freeRequest(req)
+	router.sendResponse(sending, req, nil, cc, errmsg, true)
+	router.freeRequest(req)
 }
 
 func (m *methodType) prepareContext(ctx context.Context) reflect.Value {
@@ -310,77 +268,61 @@ func (m *methodType) prepareContext(ctx context.Context) reflect.Value {
 	return reflect.Zero(m.ContextType)
 }
 
-func (server *server) serveRequest(ctx context.Context, codec serverCodec, ct string) error {
-	sending := new(sync.Mutex)
-	service, mtype, req, argv, replyv, keepReading, err := server.readRequest(codec)
-	if err != nil {
-		if !keepReading {
-			return err
-		}
-		// send a response if we actually managed to read a header.
-		if req != nil {
-			server.sendResponse(sending, req, invalidRequest, codec, err.Error(), true)
-			server.freeRequest(req)
-		}
-		return err
-	}
-	service.call(ctx, server, sending, mtype, req, argv, replyv, codec, ct)
-	return nil
-}
-
-func (server *server) getRequest() *request {
-	server.reqLock.Lock()
-	req := server.freeReq
+func (router *router) getRequest() *request {
+	router.reqLock.Lock()
+	req := router.freeReq
 	if req == nil {
 		req = new(request)
 	} else {
-		server.freeReq = req.next
+		router.freeReq = req.next
 		*req = request{}
 	}
-	server.reqLock.Unlock()
+	router.reqLock.Unlock()
 	return req
 }
 
-func (server *server) freeRequest(req *request) {
-	server.reqLock.Lock()
-	req.next = server.freeReq
-	server.freeReq = req
-	server.reqLock.Unlock()
+func (router *router) freeRequest(req *request) {
+	router.reqLock.Lock()
+	req.next = router.freeReq
+	router.freeReq = req
+	router.reqLock.Unlock()
 }
 
-func (server *server) getResponse() *response {
-	server.respLock.Lock()
-	resp := server.freeResp
+func (router *router) getResponse() *response {
+	router.respLock.Lock()
+	resp := router.freeResp
 	if resp == nil {
 		resp = new(response)
 	} else {
-		server.freeResp = resp.next
+		router.freeResp = resp.next
 		*resp = response{}
 	}
-	server.respLock.Unlock()
+	router.respLock.Unlock()
 	return resp
 }
 
-func (server *server) freeResponse(resp *response) {
-	server.respLock.Lock()
-	resp.next = server.freeResp
-	server.freeResp = resp
-	server.respLock.Unlock()
+func (router *router) freeResponse(resp *response) {
+	router.respLock.Lock()
+	resp.next = router.freeResp
+	router.freeResp = resp
+	router.respLock.Unlock()
 }
 
-func (server *server) readRequest(codec serverCodec) (service *service, mtype *methodType, req *request, argv, replyv reflect.Value, keepReading bool, err error) {
-	service, mtype, req, keepReading, err = server.readRequestHeader(codec)
+func (router *router) readRequest(r Request) (service *service, mtype *methodType, req *request, argv, replyv reflect.Value, keepReading bool, err error) {
+	cc := r.Codec()
+
+	service, mtype, req, keepReading, err = router.readHeader(cc)
 	if err != nil {
 		if !keepReading {
 			return
 		}
 		// discard body
-		codec.ReadRequestBody(nil)
+		cc.ReadBody(nil)
 		return
 	}
 	// is it a streaming request? then we don't read the body
 	if mtype.stream {
-		codec.ReadRequestBody(nil)
+		cc.ReadBody(nil)
 		return
 	}
 
@@ -393,7 +335,7 @@ func (server *server) readRequest(codec serverCodec) (service *service, mtype *m
 		argIsValue = true
 	}
 	// argv guaranteed to be a pointer now.
-	if err = codec.ReadRequestBody(argv.Interface()); err != nil {
+	if err = cc.ReadBody(argv.Interface()); err != nil {
 		return
 	}
 	if argIsValue {
@@ -406,16 +348,20 @@ func (server *server) readRequest(codec serverCodec) (service *service, mtype *m
 	return
 }
 
-func (server *server) readRequestHeader(codec serverCodec) (service *service, mtype *methodType, req *request, keepReading bool, err error) {
+func (router *router) readHeader(cc codec.Reader) (service *service, mtype *methodType, req *request, keepReading bool, err error) {
 	// Grab the request header.
-	req = server.getRequest()
-	err = codec.ReadRequestHeader(req, true)
+	msg := new(codec.Message)
+	msg.Type = codec.Request
+	req = router.getRequest()
+	req.msg = msg
+
+	err = cc.ReadHeader(msg, msg.Type)
 	if err != nil {
 		req = nil
 		if err == io.EOF || err == io.ErrUnexpectedEOF {
 			return
 		}
-		err = errors.New("rpc: server cannot decode request: " + err.Error())
+		err = errors.New("rpc: router cannot decode request: " + err.Error())
 		return
 	}
 
@@ -423,30 +369,89 @@ func (server *server) readRequestHeader(codec serverCodec) (service *service, mt
 	// we can still recover and move on to the next request.
 	keepReading = true
 
-	serviceMethod := strings.Split(req.ServiceMethod, ".")
+	serviceMethod := strings.Split(req.msg.Endpoint, ".")
 	if len(serviceMethod) != 2 {
-		err = errors.New("rpc: service/method request ill-formed: " + req.ServiceMethod)
+		err = errors.New("rpc: service/endpoint request ill-formed: " + req.msg.Endpoint)
 		return
 	}
 	// Look up the request.
-	server.mu.Lock()
-	service = server.serviceMap[serviceMethod[0]]
-	server.mu.Unlock()
+	router.mu.Lock()
+	service = router.serviceMap[serviceMethod[0]]
+	router.mu.Unlock()
 	if service == nil {
-		err = errors.New("rpc: can't find service " + req.ServiceMethod)
+		err = errors.New("rpc: can't find service " + serviceMethod[0])
 		return
 	}
 	mtype = service.method[serviceMethod[1]]
 	if mtype == nil {
-		err = errors.New("rpc: can't find method " + req.ServiceMethod)
+		err = errors.New("rpc: can't find method " + serviceMethod[1])
 	}
 	return
 }
 
-type serverCodec interface {
-	ReadRequestHeader(*request, bool) error
-	ReadRequestBody(interface{}) error
-	WriteResponse(*response, interface{}, bool) error
-
-	Close() error
+func (router *router) NewHandler(h interface{}, opts ...HandlerOption) Handler {
+	return newRpcHandler(h, opts...)
+}
+
+func (router *router) Handle(h Handler) error {
+	router.mu.Lock()
+	defer router.mu.Unlock()
+	if router.serviceMap == nil {
+		router.serviceMap = make(map[string]*service)
+	}
+
+	if len(h.Name()) == 0 {
+		return errors.New("rpc.Handle: handler has no name")
+	}
+	if !isExported(h.Name()) {
+		return errors.New("rpc.Handle: type " + h.Name() + " is not exported")
+	}
+
+	rcvr := h.Handler()
+	s := new(service)
+	s.typ = reflect.TypeOf(rcvr)
+	s.rcvr = reflect.ValueOf(rcvr)
+
+	// check name
+	if _, present := router.serviceMap[h.Name()]; present {
+		return errors.New("rpc.Handle: service already defined: " + h.Name())
+	}
+
+	s.name = h.Name()
+	s.method = make(map[string]*methodType)
+
+	// Install the methods
+	for m := 0; m < s.typ.NumMethod(); m++ {
+		method := s.typ.Method(m)
+		if mt := prepareMethod(method); mt != nil {
+			s.method[method.Name] = mt
+		}
+	}
+
+	// Check there are methods
+	if len(s.method) == 0 {
+		return errors.New("rpc Register: type " + s.name + " has no exported methods of suitable type")
+	}
+
+	// save handler
+	router.serviceMap[s.name] = s
+	return nil
+}
+
+func (router *router) ServeRequest(ctx context.Context, r Request, rsp Response) error {
+	sending := new(sync.Mutex)
+	service, mtype, req, argv, replyv, keepReading, err := router.readRequest(r)
+	if err != nil {
+		if !keepReading {
+			return err
+		}
+		// send a response if we actually managed to read a header.
+		if req != nil {
+			router.sendResponse(sending, req, invalidRequest, rsp.Codec(), err.Error(), true)
+			router.freeRequest(req)
+		}
+		return err
+	}
+	service.call(ctx, router, sending, mtype, req, argv, replyv, rsp.Codec())
+	return nil
 }

server/rpc_server.go

@@ -21,8 +21,8 @@ import (
 )
 
 type rpcServer struct {
-	rpc  *server
-	exit chan chan error
+	router *router
+	exit   chan chan error
 
 	sync.RWMutex
 	opts        Options
@@ -37,19 +37,16 @@ type rpcServer struct {
 func newRpcServer(opts ...Option) Server {
 	options := newOptions(opts...)
 	return &rpcServer{
-		opts: options,
-		rpc: &server{
-			name:         options.Name,
-			serviceMap:   make(map[string]*service),
-			hdlrWrappers: options.HdlrWrappers,
-		},
+		opts:        options,
+		router:      newRpcRouter(),
 		handlers:    make(map[string]Handler),
 		subscribers: make(map[*subscriber][]broker.Subscriber),
 		exit:        make(chan chan error),
 	}
 }
 
-func (s *rpcServer) accept(sock transport.Socket) {
+// ServeConn serves a single connection
+func (s *rpcServer) ServeConn(sock transport.Socket) {
 	defer func() {
 		// close socket
 		sock.Close()
@@ -74,8 +71,34 @@ func (s *rpcServer) accept(sock transport.Socket) {
 		// we use this Content-Type header to identify the codec needed
 		ct := msg.Header["Content-Type"]
 
-		cf, err := s.newCodec(ct)
+		// strip our headers
+		hdr := make(map[string]string)
+		for k, v := range msg.Header {
+			hdr[k] = v
+		}
+
+		// set local/remote ips
+		hdr["Local"] = sock.Local()
+		hdr["Remote"] = sock.Remote()
+
+		// create new context
+		ctx := metadata.NewContext(context.Background(), hdr)
+
+		// set the timeout if we have it
+		if len(to) > 0 {
+			if n, err := strconv.ParseUint(to, 10, 64); err == nil {
+				ctx, _ = context.WithTimeout(ctx, time.Duration(n))
+			}
+		}
+
+		// no content type
+		if len(ct) == 0 {
+			msg.Header["Content-Type"] = DefaultContentType
+			ct = DefaultContentType
+		}
+
 		// TODO: needs better error handling
+		cf, err := s.newCodec(ct)
 		if err != nil {
 			sock.Send(&transport.Message{
 				Header: map[string]string{
@@ -87,35 +110,58 @@ func (s *rpcServer) accept(sock transport.Socket) {
 			return
 		}
 
-		codec := newRpcPlusCodec(&msg, sock, cf)
+		rcodec := newRpcCodec(&msg, sock, cf)
 
-		// strip our headers
-		hdr := make(map[string]string)
-		for k, v := range msg.Header {
-			hdr[k] = v
-		}
-		delete(hdr, "Content-Type")
-		delete(hdr, "Timeout")
-
-		// set local/remote ips
-		hdr["Local"] = sock.Local()
-		hdr["Remote"] = sock.Remote()
-
-		ctx := metadata.NewContext(context.Background(), hdr)
-
-		// set the timeout if we have it
-		if len(to) > 0 {
-			if n, err := strconv.ParseUint(to, 10, 64); err == nil {
-				ctx, _ = context.WithTimeout(ctx, time.Duration(n))
-			}
+		// internal request
+		request := &rpcRequest{
+			service:     msg.Header["X-Micro-Service"],
+			endpoint:    msg.Header["X-Micro-Endpoint"],
+			contentType: ct,
+			codec:       rcodec,
+			header:      msg.Header,
+			body:        msg.Body,
+			socket:      sock,
+			stream:      true,
 		}
 
-		// TODO: needs better error handling
-		if err := s.rpc.serveRequest(ctx, codec, ct); err != nil {
+		// internal response
+		response := &rpcResponse{
+			header: make(map[string]string),
+			socket: sock,
+			codec:  rcodec,
+		}
+
+		// set router
+		r := s.opts.Router
+
+		// if nil use default router
+		if s.opts.Router == nil {
+			r = s.router
+		}
+
+		// create a wrapped function
+		handler := func(ctx context.Context, req Request, rsp interface{}) error {
+			return r.ServeRequest(ctx, req, rsp.(Response))
+		}
+
+		for i := len(s.opts.HdlrWrappers); i > 0; i-- {
+			handler = s.opts.HdlrWrappers[i-1](handler)
+		}
+
+		// TODO: handle error better
+		if err := handler(ctx, request, response); err != nil {
+			// write an error response
+			rcodec.Write(&codec.Message{
+				Header: msg.Header,
+				Error:  err.Error(),
+				Type:   codec.Error,
+			}, nil)
+
 			s.wg.Done()
-			log.Logf("Unexpected error serving request, closing socket: %v", err)
 			return
 		}
+
+		// done
 		s.wg.Done()
 	}
 }
@@ -124,7 +170,7 @@ func (s *rpcServer) newCodec(contentType string) (codec.NewCodec, error) {
 	if cf, ok := s.opts.Codecs[contentType]; ok {
 		return cf, nil
 	}
-	if cf, ok := defaultCodecs[contentType]; ok {
+	if cf, ok := DefaultCodecs[contentType]; ok {
 		return cf, nil
 	}
 	return nil, fmt.Errorf("Unsupported Content-Type: %s", contentType)
@@ -142,25 +188,25 @@ func (s *rpcServer) Init(opts ...Option) error {
 	for _, opt := range opts {
 		opt(&s.opts)
 	}
-	// update internal server
-	s.rpc = &server{
-		name:         s.opts.Name,
-		serviceMap:   s.rpc.serviceMap,
-		hdlrWrappers: s.opts.HdlrWrappers,
-	}
+
+	// update router
+	r := newRpcRouter()
+	r.serviceMap = s.router.serviceMap
+	s.router = r
+
 	s.Unlock()
 	return nil
 }
 
 func (s *rpcServer) NewHandler(h interface{}, opts ...HandlerOption) Handler {
-	return newRpcHandler(h, opts...)
+	return s.router.NewHandler(h, opts...)
 }
 
 func (s *rpcServer) Handle(h Handler) error {
 	s.Lock()
 	defer s.Unlock()
 
-	if err := s.rpc.register(h.Handler()); err != nil {
+	if err := s.router.Handle(h); err != nil {
 		return err
 	}
 
@@ -401,7 +447,7 @@ func (s *rpcServer) Start() error {
 
 	go func() {
 		for {
-			err := ts.Accept(s.accept)
+			err := ts.Accept(s.ServeConn)
 
 			// check if we're supposed to exit
 			select {

server/rpc_stream.go

@@ -3,16 +3,18 @@ package server
 import (
 	"context"
 	"sync"
+
+	"github.com/micro/go-micro/codec"
 )
 
 // Implements the Streamer interface
 type rpcStream struct {
 	sync.RWMutex
-	seq     uint64
+	id      string
 	closed  bool
 	err     error
 	request Request
-	codec   serverCodec
+	codec   codec.Codec
 	context context.Context
 }
 
@@ -28,29 +30,31 @@ func (r *rpcStream) Send(msg interface{}) error {
 	r.Lock()
 	defer r.Unlock()
 
-	resp := response{
-		ServiceMethod: r.request.Method(),
-		Seq:           r.seq,
+	resp := codec.Message{
+		Endpoint: r.request.Endpoint(),
+		Id:       r.id,
+		Type:     codec.Response,
 	}
 
-	return r.codec.WriteResponse(&resp, msg, false)
+	return r.codec.Write(&resp, msg)
 }
 
 func (r *rpcStream) Recv(msg interface{}) error {
 	r.Lock()
 	defer r.Unlock()
 
-	req := request{}
+	req := new(codec.Message)
+	req.Type = codec.Request
 
-	if err := r.codec.ReadRequestHeader(&req, false); err != nil {
+	if err := r.codec.ReadHeader(req, req.Type); err != nil {
 		// discard body
-		r.codec.ReadRequestBody(nil)
+		r.codec.ReadBody(nil)
 		return err
 	}
 
 	// we need to stay up to date with sequence numbers
-	r.seq = req.Seq
-	return r.codec.ReadRequestBody(msg)
+	r.id = req.Id
+	return r.codec.ReadBody(msg)
 }
 
 func (r *rpcStream) Error() error {

server/server.go

@@ -9,8 +9,11 @@ import (
 
 	"github.com/google/uuid"
 	"github.com/micro/go-log"
+	"github.com/micro/go-micro/codec"
+	"github.com/micro/go-micro/registry"
 )
 
+// Server is a simple micro server abstraction
 type Server interface {
 	Options() Options
 	Init(...Option) error
@@ -25,25 +28,51 @@ type Server interface {
 	String() string
 }
 
+// Router handle serving messages
+type Router interface {
+	// ServeRequest processes a request to completion
+	ServeRequest(context.Context, Request, Response) error
+}
+
+// Message is an async message interface
 type Message interface {
 	Topic() string
 	Payload() interface{}
 	ContentType() string
 }
 
+// Request is a synchronous request interface
 type Request interface {
+	// Service name requested
 	Service() string
-	Method() string
+	// Endpoint name requested
+	Endpoint() string
+	// Content type provided
 	ContentType() string
-	Request() interface{}
-	// indicates whether the request will be streamed
+	// Header of the request
+	Header() map[string]string
+	// Read the undecoded request body
+	Read() ([]byte, error)
+	// The encoded message stream
+	Codec() codec.Reader
+	// Indicates whether its a stream
 	Stream() bool
 }
 
+// Response is the response writer for unencoded messages
+type Response interface {
+	// Encoded writer
+	Codec() codec.Writer
+	// Write the header
+	WriteHeader(map[string]string)
+	// write a response directly to the client
+	Write([]byte) error
+}
+
 // Stream represents a stream established with a client.
 // A stream can be bidirectional which is indicated by the request.
 // The last error will be left in Error().
-// EOF indicated end of the stream.
+// EOF indicates end of the stream.
 type Stream interface {
 	Context() context.Context
 	Request() Request
@@ -53,6 +82,34 @@ type Stream interface {
 	Close() error
 }
 
+// Handler interface represents a request handler. It's generated
+// by passing any type of public concrete object with endpoints into server.NewHandler.
+// Most will pass in a struct.
+//
+// Example:
+//
+//      type Greeter struct {}
+//
+//      func (g *Greeter) Hello(context, request, response) error {
+//              return nil
+//      }
+//
+type Handler interface {
+	Name() string
+	Handler() interface{}
+	Endpoints() []*registry.Endpoint
+	Options() HandlerOptions
+}
+
+// Subscriber interface represents a subscription to a given topic using
+// a specific subscriber function or object with endpoints.
+type Subscriber interface {
+	Topic() string
+	Subscriber() interface{}
+	Endpoints() []*registry.Endpoint
+	Options() SubscriberOptions
+}
+
 type Option func(*Options)
 
 type HandlerOption func(*HandlerOptions)
@@ -65,6 +122,7 @@ var (
 	DefaultVersion        = "1.0.0"
 	DefaultId             = uuid.New().String()
 	DefaultServer  Server = newRpcServer()
+	DefaultRouter         = newRpcRouter()
 )
 
 // DefaultOptions returns config options for the default service
@@ -93,7 +151,7 @@ func NewSubscriber(topic string, h interface{}, opts ...SubscriberOption) Subscr
 
 // NewHandler creates a new handler interface using the default server
 // Handlers are required to be a public object with public
-// methods. Call to a service method such as Foo.Bar expects
+// endpoints. Call to a service endpoint such as Foo.Bar expects
 // the type:
 //
 //	type Foo struct {}

server/subscriber.go

@@ -164,17 +164,29 @@ func validateSubscriber(sub Subscriber) error {
 func (s *rpcServer) createSubHandler(sb *subscriber, opts Options) broker.Handler {
 	return func(p broker.Publication) error {
 		msg := p.Message()
+
+		// get codec
 		ct := msg.Header["Content-Type"]
+
+		// default content type
+		if len(ct) == 0 {
+			msg.Header["Content-Type"] = DefaultContentType
+			ct = DefaultContentType
+		}
+
+		// get codec
 		cf, err := s.newCodec(ct)
 		if err != nil {
 			return err
 		}
 
+		// copy headers
 		hdr := make(map[string]string)
 		for k, v := range msg.Header {
 			hdr[k] = v
 		}
-		delete(hdr, "Content-Type")
+
+		// create context
 		ctx := metadata.NewContext(context.Background(), hdr)
 
 		results := make(chan error, len(sb.handlers))

transport/codec/codec.go

@@ -1,10 +0,0 @@
-package codec
-
-// Codec is used for encoding where the transport doesn't natively support
-// headers in the message type. In this case the entire message is
-// encoded as the payload
-type Codec interface {
-	Marshal(interface{}) ([]byte, error)
-	Unmarshal([]byte, interface{}) error
-	String() string
-}

transport/codec/json/json.go

@@ -1,25 +0,0 @@
-package json
-
-import (
-	"encoding/json"
-
-	"github.com/micro/go-micro/transport/codec"
-)
-
-type jsonCodec struct{}
-
-func (j jsonCodec) Marshal(v interface{}) ([]byte, error) {
-	return json.Marshal(v)
-}
-
-func (j jsonCodec) Unmarshal(d []byte, v interface{}) error {
-	return json.Unmarshal(d, v)
-}
-
-func (j jsonCodec) String() string {
-	return "json"
-}
-
-func NewCodec() codec.Codec {
-	return jsonCodec{}
-}

transport/codec/noop/noop.go

@@ -1,35 +0,0 @@
-package noop
-
-import (
-	"errors"
-
-	"github.com/micro/go-micro/transport"
-	"github.com/micro/go-micro/transport/codec"
-)
-
-type noopCodec struct{}
-
-func (n noopCodec) Marshal(v interface{}) ([]byte, error) {
-	msg, ok := v.(*transport.Message)
-	if !ok {
-		return nil, errors.New("invalid message")
-	}
-	return msg.Body, nil
-}
-
-func (n noopCodec) Unmarshal(d []byte, v interface{}) error {
-	msg, ok := v.(*transport.Message)
-	if !ok {
-		return errors.New("invalid message")
-	}
-	msg.Body = d
-	return nil
-}
-
-func (n noopCodec) String() string {
-	return "noop"
-}
-
-func NewCodec() codec.Codec {
-	return noopCodec{}
-}

transport/http_proxy.go

@@ -0,0 +1,109 @@
+package transport
+
+import (
+	"bufio"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+)
+
+const (
+	proxyAuthHeader = "Proxy-Authorization"
+)
+
+func getURL(addr string) (*url.URL, error) {
+	r := &http.Request{
+		URL: &url.URL{
+			Scheme: "https",
+			Host:   addr,
+		},
+	}
+	return http.ProxyFromEnvironment(r)
+}
+
+type pbuffer struct {
+	net.Conn
+	r io.Reader
+}
+
+func (p *pbuffer) Read(b []byte) (int, error) {
+	return p.r.Read(b)
+}
+
+func proxyDial(conn net.Conn, addr string, proxyURL *url.URL) (_ net.Conn, err error) {
+	defer func() {
+		if err != nil {
+			conn.Close()
+		}
+	}()
+
+	r := &http.Request{
+		Method: http.MethodConnect,
+		URL:    &url.URL{Host: addr},
+		Header: map[string][]string{"User-Agent": {"micro/latest"}},
+	}
+
+	if user := proxyURL.User; user != nil {
+		u := user.Username()
+		p, _ := user.Password()
+		auth := []byte(u + ":" + p)
+		basicAuth := base64.StdEncoding.EncodeToString(auth)
+		r.Header.Add(proxyAuthHeader, "Basic "+basicAuth)
+	}
+
+	if err := r.Write(conn); err != nil {
+		return nil, fmt.Errorf("failed to write the HTTP request: %v", err)
+	}
+
+	br := bufio.NewReader(conn)
+	rsp, err := http.ReadResponse(br, r)
+	if err != nil {
+		return nil, fmt.Errorf("reading server HTTP response: %v", err)
+	}
+	defer rsp.Body.Close()
+	if rsp.StatusCode != http.StatusOK {
+		dump, err := httputil.DumpResponse(rsp, true)
+		if err != nil {
+			return nil, fmt.Errorf("failed to do connect handshake, status code: %s", rsp.Status)
+		}
+		return nil, fmt.Errorf("failed to do connect handshake, response: %q", dump)
+	}
+
+	return &pbuffer{Conn: conn, r: br}, nil
+}
+
+// Creates a new connection
+func newConn(dial func(string) (net.Conn, error)) func(string) (net.Conn, error) {
+	return func(addr string) (net.Conn, error) {
+		// get the proxy url
+		proxyURL, err := getURL(addr)
+		if err != nil {
+			return nil, err
+		}
+
+		// set to addr
+		callAddr := addr
+
+		// got proxy
+		if proxyURL != nil {
+			callAddr = proxyURL.Host
+		}
+
+		// dial the addr
+		c, err := dial(callAddr)
+		if err != nil {
+			return nil, err
+		}
+
+		// do proxy connect if we have proxy url
+		if proxyURL != nil {
+			c, err = proxyDial(c, addr, proxyURL)
+		}
+
+		return c, err
+	}
+}

transport/http_transport.go

@@ -1,7 +1,6 @@
 package transport
 
 import (
-	//"fmt"
 	"bufio"
 	"bytes"
 	"crypto/tls"
@@ -238,7 +237,7 @@ func (h *httpTransportSocket) Recv(m *Message) error {
 		m.Body = b
 
 		// set headers
-		for k, v := range h.r.Header {
+		for k, v := range r.Header {
 			if len(v) > 0 {
 				m.Header[k] = v[0]
 			} else {
@@ -277,6 +276,9 @@ func (h *httpTransportSocket) Recv(m *Message) error {
 		}
 	}
 
+	// set path
+	m.Header[":path"] = h.r.URL.Path
+
 	return nil
 }
 
@@ -452,9 +454,13 @@ func (h *httpTransport) Dial(addr string, opts ...DialOption) (Client, error) {
 				InsecureSkipVerify: true,
 			}
 		}
-		conn, err = tls.DialWithDialer(&net.Dialer{Timeout: dopts.Timeout}, "tcp", addr, config)
+		conn, err = newConn(func(addr string) (net.Conn, error) {
+			return tls.DialWithDialer(&net.Dialer{Timeout: dopts.Timeout}, "tcp", addr, config)
+		})(addr)
 	} else {
-		conn, err = net.DialTimeout("tcp", addr, dopts.Timeout)
+		conn, err = newConn(func(addr string) (net.Conn, error) {
+			return net.DialTimeout("tcp", addr, dopts.Timeout)
+		})(addr)
 	}
 
 	if err != nil {

transport/options.go

@@ -5,12 +5,12 @@ import (
 	"crypto/tls"
 	"time"
 
-	"github.com/micro/go-micro/transport/codec"
+	"github.com/micro/go-micro/codec"
 )
 
 type Options struct {
 	Addrs     []string
-	Codec     codec.Codec
+	Codec     codec.Marshaler
 	Secure    bool
 	TLSConfig *tls.Config
 	// Timeout sets the timeout for Send/Recv
@@ -50,7 +50,7 @@ func Addrs(addrs ...string) Option {
 
 // Codec sets the codec used for encoding where the transport
 // does not support message headers
-func Codec(c codec.Codec) Option {
+func Codec(c codec.Marshaler) Option {
 	return func(o *Options) {
 		o.Codec = c
 	}