Move the remaining consul cruft to go-plugins

config/source/consul/README.md

@@ -1,49 +0,0 @@
-# Consul Source
-
-The consul source reads config from consul key/values
-
-## Consul Format
-
-The consul source expects keys under the default prefix `/micro/config`
-
-Values are expected to be json
-
-```
-// set database
-consul kv put micro/config/database '{"address": "10.0.0.1", "port": 3306}'
-// set cache
-consul kv put micro/config/cache '{"address": "10.0.0.2", "port": 6379}'
-```
-
-Keys are split on `/` so access becomes
-
-```
-conf.Get("micro", "config", "database")
-```
-
-## New Source
-
-Specify source with data
-
-```go
-consulSource := consul.NewSource(
-	// optionally specify consul address; default to localhost:8500
-	consul.WithAddress("10.0.0.10:8500"),
-	// optionally specify prefix; defaults to /micro/config
-	consul.WithPrefix("/my/prefix"),
-  // optionally strip the provided prefix from the keys, defaults to false
-  consul.StripPrefix(true),
-)
-```
-
-## Load Source
-
-Load the source into config
-
-```go
-// Create new config
-conf := config.NewConfig()
-
-// Load consul source
-conf.Load(consulSource)
-```

config/source/consul/consul.go

@@ -1,126 +0,0 @@
-package consul
-
-import (
-	"fmt"
-	"net"
-	"time"
-
-	"github.com/hashicorp/consul/api"
-	"github.com/micro/go-micro/config/source"
-)
-
-// Currently a single consul reader
-type consul struct {
-	prefix      string
-	stripPrefix string
-	addr        string
-	opts        source.Options
-	client      *api.Client
-}
-
-var (
-	// DefaultPrefix is the prefix that consul keys will be assumed to have if you
-	// haven't specified one
-	DefaultPrefix = "/micro/config/"
-)
-
-func (c *consul) Read() (*source.ChangeSet, error) {
-	kv, _, err := c.client.KV().List(c.prefix, nil)
-	if err != nil {
-		return nil, err
-	}
-
-	if kv == nil || len(kv) == 0 {
-		return nil, fmt.Errorf("source not found: %s", c.prefix)
-	}
-
-	data, err := makeMap(c.opts.Encoder, kv, c.stripPrefix)
-	if err != nil {
-		return nil, fmt.Errorf("error reading data: %v", err)
-	}
-
-	b, err := c.opts.Encoder.Encode(data)
-	if err != nil {
-		return nil, fmt.Errorf("error reading source: %v", err)
-	}
-
-	cs := &source.ChangeSet{
-		Timestamp: time.Now(),
-		Format:    c.opts.Encoder.String(),
-		Source:    c.String(),
-		Data:      b,
-	}
-	cs.Checksum = cs.Sum()
-
-	return cs, nil
-}
-
-func (c *consul) String() string {
-	return "consul"
-}
-
-func (c *consul) Watch() (source.Watcher, error) {
-	w, err := newWatcher(c.prefix, c.addr, c.String(), c.stripPrefix, c.opts.Encoder)
-	if err != nil {
-		return nil, err
-	}
-	return w, nil
-}
-
-// NewSource creates a new consul source
-func NewSource(opts ...source.Option) source.Source {
-	options := source.NewOptions(opts...)
-
-	// use default config
-	config := api.DefaultConfig()
-
-	// use the consul config passed in the options if any
-	if co, ok := options.Context.Value(configKey{}).(*api.Config); ok {
-		config = co
-	}
-
-	// check if there are any addrs
-	a, ok := options.Context.Value(addressKey{}).(string)
-	if ok {
-		addr, port, err := net.SplitHostPort(a)
-		if ae, ok := err.(*net.AddrError); ok && ae.Err == "missing port in address" {
-			port = "8500"
-			addr = a
-			config.Address = fmt.Sprintf("%s:%s", addr, port)
-		} else if err == nil {
-			config.Address = fmt.Sprintf("%s:%s", addr, port)
-		}
-	}
-
-	dc, ok := options.Context.Value(dcKey{}).(string)
-	if ok {
-		config.Datacenter = dc
-	}
-
-	token, ok := options.Context.Value(tokenKey{}).(string)
-	if ok {
-		config.Token = token
-	}
-
-	// create the client
-	client, _ := api.NewClient(config)
-
-	prefix := DefaultPrefix
-	sp := ""
-	f, ok := options.Context.Value(prefixKey{}).(string)
-	if ok {
-		prefix = f
-	}
-
-	if b, ok := options.Context.Value(stripPrefixKey{}).(bool); ok && b {
-		sp = prefix
-	}
-
-	return &consul{
-		prefix:      prefix,
-		stripPrefix: sp,
-		addr:        config.Address,
-		opts:        options,
-		client:      client,
-	}
-}

config/source/consul/util.go

@@ -1,89 +0,0 @@
-package consul
-
-import (
-	"fmt"
-	"strings"
-
-	"github.com/hashicorp/consul/api"
-	"github.com/micro/go-micro/config/encoder"
-)
-
-type configValue interface {
-	Value() interface{}
-	Decode(encoder.Encoder, []byte) error
-}
-type configArrayValue struct {
-	v []interface{}
-}
-
-func (a *configArrayValue) Value() interface{} { return a.v }
-func (a *configArrayValue) Decode(e encoder.Encoder, b []byte) error {
-	return e.Decode(b, &a.v)
-}
-
-type configMapValue struct {
-	v map[string]interface{}
-}
-
-func (m *configMapValue) Value() interface{} { return m.v }
-func (m *configMapValue) Decode(e encoder.Encoder, b []byte) error {
-	return e.Decode(b, &m.v)
-}
-
-func makeMap(e encoder.Encoder, kv api.KVPairs, stripPrefix string) (map[string]interface{}, error) {
-
-	data := make(map[string]interface{})
-
-	// consul guarantees lexicographic order, so no need to sort
-	for _, v := range kv {
-		pathString := strings.TrimPrefix(strings.TrimPrefix(v.Key, strings.TrimPrefix(stripPrefix, "/")), "/")
-		if pathString == "" {
-			continue
-		}
-		var val configValue
-		var err error
-
-		// ensure a valid value is stored at this location
-		if len(v.Value) > 0 {
-			// try to decode into map value or array value
-			arrayV := &configArrayValue{v: []interface{}{}}
-			mapV := &configMapValue{v: map[string]interface{}{}}
-			switch {
-			case arrayV.Decode(e, v.Value) == nil:
-				val = arrayV
-			case mapV.Decode(e, v.Value) == nil:
-				val = mapV
-			default:
-				return nil, fmt.Errorf("faild decode value. path: %s, error: %s", pathString, err)
-			}
-		}
-
-		// set target at the root
-		target := data
-		path := strings.Split(pathString, "/")
-		// find (or create) the leaf node we want to put this value at
-		for _, dir := range path[:len(path)-1] {
-			if _, ok := target[dir]; !ok {
-				target[dir] = make(map[string]interface{})
-			}
-			target = target[dir].(map[string]interface{})
-		}
-
-		leafDir := path[len(path)-1]
-
-		// copy over the keys from the value
-		switch val.(type) {
-		case *configArrayValue:
-			target[leafDir] = val.Value()
-		case *configMapValue:
-			target[leafDir] = make(map[string]interface{})
-			target = target[leafDir].(map[string]interface{})
-			mapv := val.Value().(map[string]interface{})
-			for k := range mapv {
-				target[k] = mapv[k]
-			}
-		}
-	}
-
-	return data, nil
-}

config/source/consul/watcher.go

@@ -1,95 +0,0 @@
-package consul
-
-import (
-	"time"
-
-	"github.com/hashicorp/consul/api"
-	"github.com/hashicorp/consul/api/watch"
-	"github.com/micro/go-micro/config/encoder"
-	"github.com/micro/go-micro/config/source"
-)
-
-type watcher struct {
-	e           encoder.Encoder
-	name        string
-	stripPrefix string
-
-	wp   *watch.Plan
-	ch   chan *source.ChangeSet
-	exit chan bool
-}
-
-func newWatcher(key, addr, name, stripPrefix string, e encoder.Encoder) (source.Watcher, error) {
-	w := &watcher{
-		e:           e,
-		name:        name,
-		stripPrefix: stripPrefix,
-		ch:          make(chan *source.ChangeSet),
-		exit:        make(chan bool),
-	}
-
-	wp, err := watch.Parse(map[string]interface{}{"type": "keyprefix", "prefix": key})
-	if err != nil {
-		return nil, err
-	}
-
-	wp.Handler = w.handle
-
-	// wp.Run is a blocking call and will prevent newWatcher from returning
-	go wp.Run(addr)
-
-	w.wp = wp
-
-	return w, nil
-}
-
-func (w *watcher) handle(idx uint64, data interface{}) {
-	if data == nil {
-		return
-	}
-
-	kvs, ok := data.(api.KVPairs)
-	if !ok {
-		return
-	}
-
-	d, err := makeMap(w.e, kvs, w.stripPrefix)
-	if err != nil {
-		return
-	}
-
-	b, err := w.e.Encode(d)
-	if err != nil {
-		return
-	}
-
-	cs := &source.ChangeSet{
-		Timestamp: time.Now(),
-		Format:    w.e.String(),
-		Source:    w.name,
-		Data:      b,
-	}
-	cs.Checksum = cs.Sum()
-
-	w.ch <- cs
-}
-
-func (w *watcher) Next() (*source.ChangeSet, error) {
-	select {
-	case cs := <-w.ch:
-		return cs, nil
-	case <-w.exit:
-		return nil, source.ErrWatcherStopped
-	}
-}
-
-func (w *watcher) Stop() error {
-	select {
-	case <-w.exit:
-		return nil
-	default:
-		w.wp.Stop()
-		close(w.exit)
-	}
-	return nil
-}

config/source/etcd/README.md

@@ -0,0 +1,51 @@
+# Etcd Source
+
+The etcd source reads config from etcd key/values
+
+This source supports etcd version 3 and beyond.
+
+## Etcd Format
+
+The etcd source expects keys under the default prefix `/micro/config` (prefix can be changed)
+
+Values are expected to be JSON
+
+```
+// set database
+etcdctl put /micro/config/database '{"address": "10.0.0.1", "port": 3306}'
+// set cache
+etcdctl put /micro/config/cache '{"address": "10.0.0.2", "port": 6379}'
+```
+
+Keys are split on `/` so access becomes
+
+```
+conf.Get("micro", "config", "database")
+```
+
+## New Source
+
+Specify source with data
+
+```go
+etcdSource := etcd.NewSource(
+	// optionally specify etcd address; default to localhost:8500
+	etcd.WithAddress("10.0.0.10:8500"),
+	// optionally specify prefix; defaults to /micro/config
+	etcd.WithPrefix("/my/prefix"),
+	// optionally strip the provided prefix from the keys, defaults to false
+	etcd.StripPrefix(true),
+)
+```
+
+## Load Source
+
+Load the source into config
+
+```go
+// Create new config
+conf := config.NewConfig()
+
+// Load file source
+conf.Load(etcdSource)
+```

config/source/etcd/etcd.go

@@ -0,0 +1,141 @@
+package etcd
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"time"
+
+	cetcd "github.com/coreos/etcd/clientv3"
+	"github.com/coreos/etcd/mvcc/mvccpb"
+	"github.com/micro/go-micro/config/source"
+)
+
+// Currently a single etcd reader
+type etcd struct {
+	prefix      string
+	stripPrefix string
+	opts        source.Options
+	client      *cetcd.Client
+	cerr        error
+}
+
+var (
+	DefaultPrefix = "/micro/config/"
+)
+
+func (c *etcd) Read() (*source.ChangeSet, error) {
+	if c.cerr != nil {
+		return nil, c.cerr
+	}
+
+	rsp, err := c.client.Get(context.Background(), c.prefix, cetcd.WithPrefix())
+	if err != nil {
+		return nil, err
+	}
+
+	if rsp == nil || len(rsp.Kvs) == 0 {
+		return nil, fmt.Errorf("source not found: %s", c.prefix)
+	}
+
+	var kvs []*mvccpb.KeyValue
+	for _, v := range rsp.Kvs {
+		kvs = append(kvs, (*mvccpb.KeyValue)(v))
+	}
+
+	data := makeMap(c.opts.Encoder, kvs, c.stripPrefix)
+
+	b, err := c.opts.Encoder.Encode(data)
+	if err != nil {
+		return nil, fmt.Errorf("error reading source: %v", err)
+	}
+
+	cs := &source.ChangeSet{
+		Timestamp: time.Now(),
+		Source:    c.String(),
+		Data:      b,
+		Format:    c.opts.Encoder.String(),
+	}
+	cs.Checksum = cs.Sum()
+
+	return cs, nil
+}
+
+func (c *etcd) String() string {
+	return "etcd"
+}
+
+func (c *etcd) Watch() (source.Watcher, error) {
+	if c.cerr != nil {
+		return nil, c.cerr
+	}
+	cs, err := c.Read()
+	if err != nil {
+		return nil, err
+	}
+	return newWatcher(c.prefix, c.stripPrefix, c.client.Watcher, cs, c.opts)
+}
+
+func NewSource(opts ...source.Option) source.Source {
+	options := source.NewOptions(opts...)
+
+	var endpoints []string
+
+	// check if there are any addrs
+	addrs, ok := options.Context.Value(addressKey{}).([]string)
+	if ok {
+		for _, a := range addrs {
+			addr, port, err := net.SplitHostPort(a)
+			if ae, ok := err.(*net.AddrError); ok && ae.Err == "missing port in address" {
+				port = "2379"
+				addr = a
+				endpoints = append(endpoints, fmt.Sprintf("%s:%s", addr, port))
+			} else if err == nil {
+				endpoints = append(endpoints, fmt.Sprintf("%s:%s", addr, port))
+			}
+		}
+	}
+
+	if len(endpoints) == 0 {
+		endpoints = []string{"localhost:2379"}
+	}
+
+	// check dial timeout option
+	dialTimeout, ok := options.Context.Value(dialTimeoutKey{}).(time.Duration)
+	if !ok {
+		dialTimeout = 3 * time.Second // default dial timeout
+	}
+
+	config := cetcd.Config{
+		Endpoints:   endpoints,
+		DialTimeout: dialTimeout,
+	}
+
+	u, ok := options.Context.Value(authKey{}).(*authCreds)
+	if ok {
+		config.Username = u.Username
+		config.Password = u.Password
+	}
+
+	// use default config
+	client, err := cetcd.New(config)
+
+	prefix := DefaultPrefix
+	sp := ""
+	f, ok := options.Context.Value(prefixKey{}).(string)
+	if ok {
+		prefix = f
+	}
+
+	if b, ok := options.Context.Value(stripPrefixKey{}).(bool); ok && b {
+		sp = prefix
+	}
+
+	return &etcd{
+		prefix:      prefix,
+		stripPrefix: sp,
+		opts:        options,
+		client:      client,
+		cerr:        err,
+	}
+}

config/source/etcd/options.go

@@ -1,21 +1,25 @@
-package consul
+package etcd
 
 import (
 	"context"
+	"time"
 
-	"github.com/hashicorp/consul/api"
 	"github.com/micro/go-micro/config/source"
 )
 
 type addressKey struct{}
 type prefixKey struct{}
 type stripPrefixKey struct{}
-type dcKey struct{}
+type authKey struct{}
-type tokenKey struct{}
+type dialTimeoutKey struct{}
-type configKey struct{}
 
-// WithAddress sets the consul address
+type authCreds struct {
-func WithAddress(a string) source.Option {
+	Username string
+	Password string
+}
+
+// WithAddress sets the etcd address
+func WithAddress(a ...string) source.Option {
 	return func(o *source.Options) {
 		if o.Context == nil {
 			o.Context = context.Background()
@@ -45,31 +49,22 @@ func StripPrefix(strip bool) source.Option {
 	}
 }
 
-func WithDatacenter(p string) source.Option {
+// Auth allows you to specify username/password
+func Auth(username, password string) source.Option {
 	return func(o *source.Options) {
 		if o.Context == nil {
 			o.Context = context.Background()
 		}
-		o.Context = context.WithValue(o.Context, dcKey{}, p)
+		o.Context = context.WithValue(o.Context, authKey{}, &authCreds{Username: username, Password: password})
 	}
 }
 
-// WithToken sets the key token to use
+// WithDialTimeout set the time out for dialing to etcd
-func WithToken(p string) source.Option {
+func WithDialTimeout(timeout time.Duration) source.Option {
 	return func(o *source.Options) {
 		if o.Context == nil {
 			o.Context = context.Background()
 		}
-		o.Context = context.WithValue(o.Context, tokenKey{}, p)
+		o.Context = context.WithValue(o.Context, dialTimeoutKey{}, timeout)
-	}
-}
-
-// WithConfig set consul-specific options
-func WithConfig(c *api.Config) source.Option {
-	return func(o *source.Options) {
-		if o.Context == nil {
-			o.Context = context.Background()
-		}
-		o.Context = context.WithValue(o.Context, configKey{}, c)
 	}
 }

config/source/etcd/util.go

@@ -0,0 +1,89 @@
+package etcd
+
+import (
+	"strings"
+
+	"github.com/coreos/etcd/clientv3"
+	"github.com/coreos/etcd/mvcc/mvccpb"
+	"github.com/micro/go-micro/config/encoder"
+)
+
+func makeEvMap(e encoder.Encoder, data map[string]interface{}, kv []*clientv3.Event, stripPrefix string) map[string]interface{} {
+	if data == nil {
+		data = make(map[string]interface{})
+	}
+
+	for _, v := range kv {
+		switch mvccpb.Event_EventType(v.Type) {
+		case mvccpb.DELETE:
+			data = update(e, data, (*mvccpb.KeyValue)(v.Kv), "delete", stripPrefix)
+		default:
+			data = update(e, data, (*mvccpb.KeyValue)(v.Kv), "insert", stripPrefix)
+		}
+	}
+
+	return data
+}
+
+func makeMap(e encoder.Encoder, kv []*mvccpb.KeyValue, stripPrefix string) map[string]interface{} {
+	data := make(map[string]interface{})
+
+	for _, v := range kv {
+		data = update(e, data, v, "put", stripPrefix)
+	}
+
+	return data
+}
+
+func update(e encoder.Encoder, data map[string]interface{}, v *mvccpb.KeyValue, action, stripPrefix string) map[string]interface{} {
+	// remove prefix if non empty, and ensure leading / is removed as well
+	vkey := strings.TrimPrefix(strings.TrimPrefix(string(v.Key), stripPrefix), "/")
+	// split on prefix
+	haveSplit := strings.Contains(vkey, "/")
+	keys := strings.Split(vkey, "/")
+
+	var vals interface{}
+	e.Decode(v.Value, &vals)
+
+	if !haveSplit && len(keys) == 1 {
+		switch action {
+		case "delete":
+			data = make(map[string]interface{})
+		default:
+			v, ok := vals.(map[string]interface{})
+			if ok {
+				data = v
+			}
+		}
+		return data
+	}
+
+	// set data for first iteration
+	kvals := data
+	// iterate the keys and make maps
+	for i, k := range keys {
+		kval, ok := kvals[k].(map[string]interface{})
+		if !ok {
+			// create next map
+			kval = make(map[string]interface{})
+			// set it
+			kvals[k] = kval
+		}
+
+		// last key: write vals
+		if l := len(keys) - 1; i == l {
+			switch action {
+			case "delete":
+				delete(kvals, k)
+			default:
+				kvals[k] = vals
+			}
+			break
+		}
+
+		// set kvals for next iterator
+		kvals = kval
+	}
+
+	return data
+}

config/source/etcd/watcher.go

@@ -0,0 +1,113 @@
+package etcd
+
+import (
+	"context"
+	"errors"
+	"sync"
+	"time"
+
+	cetcd "github.com/coreos/etcd/clientv3"
+	"github.com/micro/go-micro/config/source"
+)
+
+type watcher struct {
+	opts        source.Options
+	name        string
+	stripPrefix string
+
+	sync.RWMutex
+	cs *source.ChangeSet
+
+	ch   chan *source.ChangeSet
+	exit chan bool
+}
+
+func newWatcher(key, strip string, wc cetcd.Watcher, cs *source.ChangeSet, opts source.Options) (source.Watcher, error) {
+	w := &watcher{
+		opts:        opts,
+		name:        "etcd",
+		stripPrefix: strip,
+		cs:          cs,
+		ch:          make(chan *source.ChangeSet),
+		exit:        make(chan bool),
+	}
+
+	ch := wc.Watch(context.Background(), key, cetcd.WithPrefix())
+
+	go w.run(wc, ch)
+
+	return w, nil
+}
+
+func (w *watcher) handle(evs []*cetcd.Event) {
+	w.RLock()
+	data := w.cs.Data
+	w.RUnlock()
+
+	var vals map[string]interface{}
+
+	// unpackage existing changeset
+	if err := w.opts.Encoder.Decode(data, &vals); err != nil {
+		return
+	}
+
+	// update base changeset
+	d := makeEvMap(w.opts.Encoder, vals, evs, w.stripPrefix)
+
+	// pack the changeset
+	b, err := w.opts.Encoder.Encode(d)
+	if err != nil {
+		return
+	}
+
+	// create new changeset
+	cs := &source.ChangeSet{
+		Timestamp: time.Now(),
+		Source:    w.name,
+		Data:      b,
+		Format:    w.opts.Encoder.String(),
+	}
+	cs.Checksum = cs.Sum()
+
+	// set base change set
+	w.Lock()
+	w.cs = cs
+	w.Unlock()
+
+	// send update
+	w.ch <- cs
+}
+
+func (w *watcher) run(wc cetcd.Watcher, ch cetcd.WatchChan) {
+	for {
+		select {
+		case rsp, ok := <-ch:
+			if !ok {
+				return
+			}
+			w.handle(rsp.Events)
+		case <-w.exit:
+			wc.Close()
+			return
+		}
+	}
+}
+
+func (w *watcher) Next() (*source.ChangeSet, error) {
+	select {
+	case cs := <-w.ch:
+		return cs, nil
+	case <-w.exit:
+		return nil, errors.New("watcher stopped")
+	}
+}
+
+func (w *watcher) Stop() error {
+	select {
+	case <-w.exit:
+		return nil
+	default:
+		close(w.exit)
+	}
+	return nil
+}

sync/leader/consul/consul.go

@@ -1,158 +0,0 @@
-package consul
-
-import (
-	"fmt"
-	"log"
-	"net"
-	"os"
-	"path"
-	"sync"
-
-	"github.com/hashicorp/consul/api"
-	"github.com/hashicorp/consul/api/watch"
-	"github.com/micro/go-micro/sync/leader"
-)
-
-type consulLeader struct {
-	opts leader.Options
-	c    *api.Client
-}
-
-type consulElected struct {
-	c    *api.Client
-	l    *api.Lock
-	id   string
-	key  string
-	opts leader.ElectOptions
-
-	mtx sync.RWMutex
-	rv  <-chan struct{}
-}
-
-func (c *consulLeader) Elect(id string, opts ...leader.ElectOption) (leader.Elected, error) {
-	var options leader.ElectOptions
-	for _, o := range opts {
-		o(&options)
-	}
-
-	key := path.Join("micro/leader", c.opts.Group)
-
-	lc, err := c.c.LockOpts(&api.LockOptions{
-		Key:   key,
-		Value: []byte(id),
-	})
-	if err != nil {
-		return nil, err
-	}
-
-	rv, err := lc.Lock(nil)
-	if err != nil {
-		return nil, err
-	}
-
-	return &consulElected{
-		c:    c.c,
-		key:  key,
-		rv:   rv,
-		id:   id,
-		l:    lc,
-		opts: options,
-	}, nil
-}
-
-func (c *consulLeader) Follow() chan string {
-	ch := make(chan string, 1)
-
-	key := path.Join("/micro/leader", c.opts.Group)
-
-	p, err := watch.Parse(map[string]interface{}{
-		"type": "key",
-		"key":  key,
-	})
-	if err != nil {
-		return ch
-	}
-	p.Handler = func(idx uint64, raw interface{}) {
-		if raw == nil {
-			return // ignore
-		}
-		v, ok := raw.(*api.KVPair)
-		if !ok || v == nil {
-			return // ignore
-		}
-		ch <- string(v.Value)
-	}
-
-	go p.RunWithClientAndLogger(c.c, log.New(os.Stdout, "consul: ", log.Lshortfile))
-	return ch
-}
-
-func (c *consulLeader) String() string {
-	return "consul"
-}
-
-func (c *consulElected) Id() string {
-	return c.id
-}
-
-func (c *consulElected) Reelect() error {
-	rv, err := c.l.Lock(nil)
-	if err != nil {
-		return err
-	}
-
-	c.mtx.Lock()
-	c.rv = rv
-	c.mtx.Unlock()
-	return nil
-}
-
-func (c *consulElected) Revoked() chan bool {
-	ch := make(chan bool, 1)
-	c.mtx.RLock()
-	rv := c.rv
-	c.mtx.RUnlock()
-
-	go func() {
-		<-rv
-		ch <- true
-		close(ch)
-	}()
-
-	return ch
-}
-
-func (c *consulElected) Resign() error {
-	return c.l.Unlock()
-}
-
-func NewLeader(opts ...leader.Option) leader.Leader {
-	options := leader.Options{
-		Group: "default",
-	}
-	for _, o := range opts {
-		o(&options)
-	}
-
-	config := api.DefaultConfig()
-
-	// set host
-	// config.Host something
-	// check if there are any addrs
-	if len(options.Nodes) > 0 {
-		addr, port, err := net.SplitHostPort(options.Nodes[0])
-		if ae, ok := err.(*net.AddrError); ok && ae.Err == "missing port in address" {
-			port = "8500"
-			config.Address = fmt.Sprintf("%s:%s", addr, port)
-		} else if err == nil {
-			config.Address = fmt.Sprintf("%s:%s", addr, port)
-		}
-	}
-
-	client, _ := api.NewClient(config)
-
-	return &consulLeader{
-		opts: options,
-		c:    client,
-	}
-}

sync/leader/etcd/etcd.go

@@ -0,0 +1,145 @@
+package etcd
+
+import (
+	"context"
+	"log"
+	"path"
+	"strings"
+
+	client "github.com/coreos/etcd/clientv3"
+	cc "github.com/coreos/etcd/clientv3/concurrency"
+	"github.com/micro/go-micro/sync/leader"
+)
+
+type etcdLeader struct {
+	opts   leader.Options
+	path   string
+	client *client.Client
+}
+
+type etcdElected struct {
+	s  *cc.Session
+	e  *cc.Election
+	id string
+}
+
+func (e *etcdLeader) Elect(id string, opts ...leader.ElectOption) (leader.Elected, error) {
+	var options leader.ElectOptions
+	for _, o := range opts {
+		o(&options)
+	}
+
+	// make path
+	path := path.Join(e.path, strings.Replace(id, "/", "-", -1))
+
+	s, err := cc.NewSession(e.client)
+	if err != nil {
+		return nil, err
+	}
+
+	l := cc.NewElection(s, path)
+
+	ctx, _ := context.WithCancel(context.Background())
+
+	if err := l.Campaign(ctx, id); err != nil {
+		return nil, err
+	}
+
+	return &etcdElected{
+		e:  l,
+		id: id,
+	}, nil
+}
+
+func (e *etcdLeader) Follow() chan string {
+	ch := make(chan string)
+
+	s, err := cc.NewSession(e.client)
+	if err != nil {
+		return ch
+	}
+
+	l := cc.NewElection(s, e.path)
+	ech := l.Observe(context.Background())
+
+	go func() {
+		for {
+			select {
+			case r, ok := <-ech:
+				if !ok {
+					return
+				}
+				ch <- string(r.Kvs[0].Value)
+			}
+		}
+	}()
+
+	return ch
+}
+
+func (e *etcdLeader) String() string {
+	return "etcd"
+}
+
+func (e *etcdElected) Reelect() error {
+	ctx, _ := context.WithCancel(context.Background())
+	return e.e.Campaign(ctx, e.id)
+}
+
+func (e *etcdElected) Revoked() chan bool {
+	ch := make(chan bool, 1)
+	ech := e.e.Observe(context.Background())
+
+	go func() {
+		for r := range ech {
+			if string(r.Kvs[0].Value) != e.id {
+				ch <- true
+				close(ch)
+				return
+			}
+		}
+	}()
+
+	return ch
+}
+
+func (e *etcdElected) Resign() error {
+	return e.e.Resign(context.Background())
+}
+
+func (e *etcdElected) Id() string {
+	return e.id
+}
+
+func NewLeader(opts ...leader.Option) leader.Leader {
+	var options leader.Options
+	for _, o := range opts {
+		o(&options)
+	}
+
+	var endpoints []string
+
+	for _, addr := range options.Nodes {
+		if len(addr) > 0 {
+			endpoints = append(endpoints, addr)
+		}
+	}
+
+	if len(endpoints) == 0 {
+		endpoints = []string{"http://127.0.0.1:2379"}
+	}
+
+	// TODO: parse addresses
+	c, err := client.New(client.Config{
+		Endpoints: endpoints,
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	return &etcdLeader{
+		path:   "/micro/leader",
+		client: c,
+		opts:   options,
+	}
+}