Merge pull request #810 from milosgajdos83/etcd

First commit to add etcd registry support

config/cmd/cmd.go

@@ -27,6 +27,7 @@ import (
 	// registries
 	"github.com/micro/go-micro/registry"
 	"github.com/micro/go-micro/registry/consul"
+	"github.com/micro/go-micro/registry/etcd"
 	"github.com/micro/go-micro/registry/gossip"
 	"github.com/micro/go-micro/registry/mdns"
 	rmem "github.com/micro/go-micro/registry/memory"
@@ -154,7 +155,7 @@ var (
 		cli.StringFlag{
 			Name:   "registry",
 			EnvVar: "MICRO_REGISTRY",
-			Usage:  "Registry for discovery. consul, mdns",
+			Usage:  "Registry for discovery. consul, etcd, mdns",
 		},
 		cli.StringFlag{
 			Name:   "registry_address",
@@ -194,6 +195,7 @@ var (
 		"go.micro.registry": regSrv.NewRegistry,
 		"service":           regSrv.NewRegistry,
 		"consul":            consul.NewRegistry,
+		"etcd":              etcd.NewRegistry,
 		"gossip":            gossip.NewRegistry,
 		"mdns":              mdns.NewRegistry,
 		"memory":            rmem.NewRegistry,

go.mod

@@ -7,6 +7,9 @@ require (
 	github.com/beevik/ntp v0.2.0
 	github.com/bitly/go-simplejson v0.5.0
 	github.com/bwmarrin/discordgo v0.19.0
+	github.com/coreos/etcd v3.3.15+incompatible
+	github.com/coreos/go-systemd v0.0.0-20190719114852-fd7a80b32e1f // indirect
+	github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f // indirect
 	github.com/forestgiant/sliceutil v0.0.0-20160425183142-94783f95db6c
 	github.com/fsnotify/fsnotify v1.4.7
 	github.com/fsouza/go-dockerclient v1.4.4
@@ -33,6 +36,9 @@ require (
 	github.com/nlopes/slack v0.6.0
 	github.com/pkg/errors v0.8.1
 	github.com/technoweenie/multipartstreamer v1.0.1 // indirect
+	go.uber.org/atomic v1.4.0 // indirect
+	go.uber.org/multierr v1.2.0 // indirect
+	go.uber.org/zap v1.10.0 // indirect
 	golang.org/x/crypto v0.0.0-20191001170739-f9e2070545dc
 	golang.org/x/net v0.0.0-20190930134127-c5a3c61f89f3
 	google.golang.org/grpc v1.24.0

go.sum

@@ -26,6 +26,12 @@ github.com/cheekybits/genny v1.0.0/go.mod h1:+tQajlRqAUrPI7DOSpB0XAqZYtQakVtB7wX
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/containerd/continuity v0.0.0-20181203112020-004b46473808 h1:4BX8f882bXEDKfWIf0wa8HRvpnBoPszJJXL+TVbBw4M=
 github.com/containerd/continuity v0.0.0-20181203112020-004b46473808/go.mod h1:GL3xCUCBDV3CZiTSEKksMWbLE66hEyuu9qyDOOqM47Y=
+github.com/coreos/etcd v3.3.15+incompatible h1:+9RjdC18gMxNQVvSiXvObLu29mOFmkgdsB4cRTlV+EE=
+github.com/coreos/etcd v3.3.15+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
+github.com/coreos/go-systemd v0.0.0-20190719114852-fd7a80b32e1f h1:JOrtw2xFKzlg+cbHpyrpLDmnN1HqhBfnX7WDiW7eG2c=
+github.com/coreos/go-systemd v0.0.0-20190719114852-fd7a80b32e1f/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
+github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f h1:lBNOc5arjvs8E5mO2tbpBpLoyyu8B6e44T7hJy6potg=
+github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f/go.mod h1:E3G3o1h8I7cfcXa63jLwjI0eiQQMgzzUDFVpN/nH/eA=
 github.com/creack/pty v1.1.7/go.mod h1:lj5s0c3V2DBrqTV7llrYr5NG6My20zk30Fl46Y7DoTY=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -209,6 +215,12 @@ github.com/technoweenie/multipartstreamer v1.0.1 h1:XRztA5MXiR1TIRHxH2uNxXxaIkKQ
 github.com/technoweenie/multipartstreamer v1.0.1/go.mod h1:jNVxdtShOxzAsukZwTSw6MDx5eUJoiEBsSvzDU9uzog=
 github.com/xanzy/ssh-agent v0.2.1 h1:TCbipTQL2JiiCprBWx9frJ2eJlCYT00NmctrHxVAr70=
 github.com/xanzy/ssh-agent v0.2.1/go.mod h1:mLlQY/MoOhWBj+gOGMQkOeiEvkx+8pJSI+0Bx9h2kr4=
+go.uber.org/atomic v1.4.0 h1:cxzIVoETapQEqDhQu3QfnvXAV4AlzcvUCxkVUFw3+EU=
+go.uber.org/atomic v1.4.0/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
+go.uber.org/multierr v1.2.0 h1:6I+W7f5VwC5SV9dNrZ3qXrDB9mD0dyGOi/ZJmYw03T4=
+go.uber.org/multierr v1.2.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/0=
+go.uber.org/zap v1.10.0 h1:ORx85nbTijNz8ljznvCMR1ZBIPKFn3jQrag10X2AsuM=
+go.uber.org/zap v1.10.0/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
 golang.org/x/crypto v0.0.0-20181029021203-45a5f77698d3/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20181030102418-4d3f4d9ffa16/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20181203042331-505ab145d0a9/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=

registry/etcd/etcd.go

@@ -0,0 +1,309 @@
+// Package etcd provides an etcd service registry
+package etcd
+
+import (
+	"context"
+	"crypto/tls"
+	"encoding/json"
+	"errors"
+	"path"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/coreos/etcd/clientv3"
+	"github.com/micro/go-micro/registry"
+
+	"github.com/coreos/etcd/etcdserver/api/v3rpc/rpctypes"
+	hash "github.com/mitchellh/hashstructure"
+)
+
+var (
+	prefix = "/micro-registry"
+)
+
+type etcdRegistry struct {
+	client  *clientv3.Client
+	options registry.Options
+	sync.Mutex
+	register map[string]uint64
+	leases   map[string]clientv3.LeaseID
+}
+
+func NewRegistry(opts ...registry.Option) registry.Registry {
+	e := &etcdRegistry{
+		options:  registry.Options{},
+		register: make(map[string]uint64),
+		leases:   make(map[string]clientv3.LeaseID),
+	}
+	configure(e, opts...)
+	return e
+}
+
+func configure(e *etcdRegistry, opts ...registry.Option) error {
+	config := clientv3.Config{
+		Endpoints: []string{"127.0.0.1:2379"},
+	}
+
+	for _, o := range opts {
+		o(&e.options)
+	}
+
+	if e.options.Timeout == 0 {
+		e.options.Timeout = 5 * time.Second
+	}
+
+	if e.options.Secure || e.options.TLSConfig != nil {
+		tlsConfig := e.options.TLSConfig
+		if tlsConfig == nil {
+			tlsConfig = &tls.Config{
+				InsecureSkipVerify: true,
+			}
+		}
+
+		config.TLS = tlsConfig
+	}
+
+	if e.options.Context != nil {
+		u, ok := e.options.Context.Value(authKey{}).(*authCreds)
+		if ok {
+			config.Username = u.Username
+			config.Password = u.Password
+		}
+	}
+
+	var cAddrs []string
+
+	for _, addr := range e.options.Addrs {
+		if len(addr) == 0 {
+			continue
+		}
+		cAddrs = append(cAddrs, addr)
+	}
+
+	// if we got addrs then we'll update
+	if len(cAddrs) > 0 {
+		config.Endpoints = cAddrs
+	}
+
+	cli, err := clientv3.New(config)
+	if err != nil {
+		return err
+	}
+	e.client = cli
+	return nil
+}
+
+func encode(s *registry.Service) string {
+	b, _ := json.Marshal(s)
+	return string(b)
+}
+
+func decode(ds []byte) *registry.Service {
+	var s *registry.Service
+	json.Unmarshal(ds, &s)
+	return s
+}
+
+func nodePath(s, id string) string {
+	service := strings.Replace(s, "/", "-", -1)
+	node := strings.Replace(id, "/", "-", -1)
+	return path.Join(prefix, service, node)
+}
+
+func servicePath(s string) string {
+	return path.Join(prefix, strings.Replace(s, "/", "-", -1))
+}
+
+func (e *etcdRegistry) Init(opts ...registry.Option) error {
+	return configure(e, opts...)
+}
+
+func (e *etcdRegistry) Options() registry.Options {
+	return e.options
+}
+
+func (e *etcdRegistry) Deregister(s *registry.Service) error {
+	if len(s.Nodes) == 0 {
+		return errors.New("Require at least one node")
+	}
+
+	e.Lock()
+	// delete our hash of the service
+	delete(e.register, s.Name)
+	// delete our lease of the service
+	delete(e.leases, s.Name)
+	e.Unlock()
+
+	ctx, cancel := context.WithTimeout(context.Background(), e.options.Timeout)
+	defer cancel()
+
+	for _, node := range s.Nodes {
+		_, err := e.client.Delete(ctx, nodePath(s.Name, node.Id))
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (e *etcdRegistry) Register(s *registry.Service, opts ...registry.RegisterOption) error {
+	if len(s.Nodes) == 0 {
+		return errors.New("Require at least one node")
+	}
+
+	var leaseNotFound bool
+	//refreshing lease if existing
+	leaseID, ok := e.leases[s.Name]
+	if ok {
+		if _, err := e.client.KeepAliveOnce(context.TODO(), leaseID); err != nil {
+			if err != rpctypes.ErrLeaseNotFound {
+				return err
+			}
+
+			// lease not found do register
+			leaseNotFound = true
+		}
+	}
+
+	// create hash of service; uint64
+	h, err := hash.Hash(s, nil)
+	if err != nil {
+		return err
+	}
+
+	// get existing hash
+	e.Lock()
+	v, ok := e.register[s.Name]
+	e.Unlock()
+
+	// the service is unchanged, skip registering
+	if ok && v == h && !leaseNotFound {
+		return nil
+	}
+
+	service := &registry.Service{
+		Name:      s.Name,
+		Version:   s.Version,
+		Metadata:  s.Metadata,
+		Endpoints: s.Endpoints,
+	}
+
+	var options registry.RegisterOptions
+	for _, o := range opts {
+		o(&options)
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), e.options.Timeout)
+	defer cancel()
+
+	var lgr *clientv3.LeaseGrantResponse
+	if options.TTL.Seconds() > 0 {
+		lgr, err = e.client.Grant(ctx, int64(options.TTL.Seconds()))
+		if err != nil {
+			return err
+		}
+	}
+
+	for _, node := range s.Nodes {
+		service.Nodes = []*registry.Node{node}
+		if lgr != nil {
+			_, err = e.client.Put(ctx, nodePath(service.Name, node.Id), encode(service), clientv3.WithLease(lgr.ID))
+		} else {
+			_, err = e.client.Put(ctx, nodePath(service.Name, node.Id), encode(service))
+		}
+		if err != nil {
+			return err
+		}
+	}
+
+	e.Lock()
+	// save our hash of the service
+	e.register[s.Name] = h
+	// save our leaseID of the service
+	if lgr != nil {
+		e.leases[s.Name] = lgr.ID
+	}
+	e.Unlock()
+
+	return nil
+}
+
+func (e *etcdRegistry) GetService(name string) ([]*registry.Service, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), e.options.Timeout)
+	defer cancel()
+
+	rsp, err := e.client.Get(ctx, servicePath(name)+"/", clientv3.WithPrefix(), clientv3.WithSort(clientv3.SortByKey, clientv3.SortDescend))
+	if err != nil {
+		return nil, err
+	}
+
+	if len(rsp.Kvs) == 0 {
+		return nil, registry.ErrNotFound
+	}
+
+	serviceMap := map[string]*registry.Service{}
+
+	for _, n := range rsp.Kvs {
+		if sn := decode(n.Value); sn != nil {
+			s, ok := serviceMap[sn.Version]
+			if !ok {
+				s = &registry.Service{
+					Name:      sn.Name,
+					Version:   sn.Version,
+					Metadata:  sn.Metadata,
+					Endpoints: sn.Endpoints,
+				}
+				serviceMap[s.Version] = s
+			}
+
+			for _, node := range sn.Nodes {
+				s.Nodes = append(s.Nodes, node)
+			}
+		}
+	}
+
+	var services []*registry.Service
+	for _, service := range serviceMap {
+		services = append(services, service)
+	}
+	return services, nil
+}
+
+func (e *etcdRegistry) ListServices() ([]*registry.Service, error) {
+	var services []*registry.Service
+	nameSet := make(map[string]struct{})
+
+	ctx, cancel := context.WithTimeout(context.Background(), e.options.Timeout)
+	defer cancel()
+
+	rsp, err := e.client.Get(ctx, prefix, clientv3.WithPrefix(), clientv3.WithSort(clientv3.SortByKey, clientv3.SortDescend))
+	if err != nil {
+		return nil, err
+	}
+
+	if len(rsp.Kvs) == 0 {
+		return []*registry.Service{}, nil
+	}
+
+	for _, n := range rsp.Kvs {
+		if sn := decode(n.Value); sn != nil {
+			nameSet[sn.Name] = struct{}{}
+		}
+	}
+	for k := range nameSet {
+		service := &registry.Service{}
+		service.Name = k
+		services = append(services, service)
+	}
+
+	return services, nil
+}
+
+func (e *etcdRegistry) Watch(opts ...registry.WatchOption) (registry.Watcher, error) {
+	return newEtcdWatcher(e, e.options.Timeout, opts...)
+}
+
+func (e *etcdRegistry) String() string {
+	return "etcd"
+}

registry/etcd/options.go

@@ -0,0 +1,24 @@
+package etcd
+
+import (
+	"context"
+
+	"github.com/micro/go-micro/registry"
+)
+
+type authKey struct{}
+
+type authCreds struct {
+	Username string
+	Password string
+}
+
+// Auth allows you to specify username/password
+func Auth(username, password string) registry.Option {
+	return func(o *registry.Options) {
+		if o.Context == nil {
+			o.Context = context.Background()
+		}
+		o.Context = context.WithValue(o.Context, authKey{}, &authCreds{Username: username, Password: password})
+	}
+}

registry/etcd/watcher.go

@@ -0,0 +1,88 @@
+package etcd
+
+import (
+	"context"
+	"errors"
+	"time"
+
+	"github.com/coreos/etcd/clientv3"
+	"github.com/micro/go-micro/registry"
+)
+
+type etcdWatcher struct {
+	stop    chan bool
+	w       clientv3.WatchChan
+	client  *clientv3.Client
+	timeout time.Duration
+}
+
+func newEtcdWatcher(r *etcdRegistry, timeout time.Duration, opts ...registry.WatchOption) (registry.Watcher, error) {
+	var wo registry.WatchOptions
+	for _, o := range opts {
+		o(&wo)
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	stop := make(chan bool, 1)
+
+	go func() {
+		<-stop
+		cancel()
+	}()
+
+	watchPath := prefix
+	if len(wo.Service) > 0 {
+		watchPath = servicePath(wo.Service) + "/"
+	}
+
+	return &etcdWatcher{
+		stop:    stop,
+		w:       r.client.Watch(ctx, watchPath, clientv3.WithPrefix(), clientv3.WithPrevKV()),
+		client:  r.client,
+		timeout: timeout,
+	}, nil
+}
+
+func (ew *etcdWatcher) Next() (*registry.Result, error) {
+	for wresp := range ew.w {
+		if wresp.Err() != nil {
+			return nil, wresp.Err()
+		}
+		for _, ev := range wresp.Events {
+			service := decode(ev.Kv.Value)
+			var action string
+
+			switch ev.Type {
+			case clientv3.EventTypePut:
+				if ev.IsCreate() {
+					action = "create"
+				} else if ev.IsModify() {
+					action = "update"
+				}
+			case clientv3.EventTypeDelete:
+				action = "delete"
+
+				// get service from prevKv
+				service = decode(ev.PrevKv.Value)
+			}
+
+			if service == nil {
+				continue
+			}
+			return &registry.Result{
+				Action:  action,
+				Service: service,
+			}, nil
+		}
+	}
+	return nil, errors.New("could not get next")
+}
+
+func (ew *etcdWatcher) Stop() {
+	select {
+	case <-ew.stop:
+		return
+	default:
+		close(ew.stop)
+	}
+}