Add basic etcd registry implementation

cmd/cmd.go

@@ -20,6 +20,7 @@ import (
 
 	// registries
 	"github.com/myodc/go-micro/registry/consul"
+	"github.com/myodc/go-micro/registry/etcd"
 	"github.com/myodc/go-micro/registry/kubernetes"
 
 	// transport
@@ -105,6 +106,8 @@ func Setup(c *cli.Context) error {
 		registry.DefaultRegistry = kubernetes.NewRegistry(rAddrs)
 	case "consul":
 		registry.DefaultRegistry = consul.NewRegistry(rAddrs)
+	case "etcd":
+		registry.DefaultRegistry = etcd.NewRegistry(rAddrs)
 	}
 
 	tAddrs := strings.Split(c.String("transport_address"), ",")

registry/etcd/etcd.go

@@ -0,0 +1,177 @@
+package etcd
+
+import (
+	"encoding/json"
+	"errors"
+	"path/filepath"
+	"strings"
+	"sync"
+
+	"github.com/coreos/go-etcd/etcd"
+	"github.com/myodc/go-micro/registry"
+)
+
+var (
+	prefix = "/micro-registry"
+)
+
+type etcdRegistry struct {
+	client *etcd.Client
+
+	sync.RWMutex
+	services map[string]*registry.Service
+}
+
+func encode(s *registry.Service) string {
+	b, _ := json.Marshal(s)
+	return string(b)
+}
+
+func decode(ds string) *registry.Service {
+	var s *registry.Service
+	json.Unmarshal([]byte(ds), &s)
+	return s
+}
+
+func nodePath(s, id string) string {
+	service := strings.Replace(s, "/", "-", -1)
+	node := strings.Replace(id, "/", "-", -1)
+	return filepath.Join(prefix, service, node)
+}
+
+func servicePath(s string) string {
+	return filepath.Join(prefix, strings.Replace(s, "/", "-", -1))
+}
+
+func (e *etcdRegistry) Deregister(s *registry.Service) error {
+	if len(s.Nodes) == 0 {
+		return errors.New("Require at least one node")
+	}
+
+	for _, node := range s.Nodes {
+		_, err := e.client.Delete(nodePath(s.Name, node.Id), false)
+		if err != nil {
+			return err
+		}
+	}
+
+	e.client.DeleteDir(servicePath(s.Name))
+	return nil
+}
+
+func (e *etcdRegistry) Register(s *registry.Service) error {
+	if len(s.Nodes) == 0 {
+		return errors.New("Require at least one node")
+	}
+
+	service := &registry.Service{
+		Name:     s.Name,
+		Metadata: s.Metadata,
+	}
+
+	e.client.CreateDir(servicePath(s.Name), 0)
+
+	for _, node := range s.Nodes {
+		service.Nodes = []*registry.Node{node}
+		_, err := e.client.Create(nodePath(service.Name, node.Id), encode(service), 0)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (e *etcdRegistry) GetService(name string) (*registry.Service, error) {
+	e.RLock()
+	service, ok := e.services[name]
+	e.RUnlock()
+
+	if ok {
+		return service, nil
+	}
+
+	rsp, err := e.client.Get(servicePath(name), false, false)
+	if err != nil && !strings.HasPrefix(err.Error(), "100: Key not found") {
+		return nil, err
+	}
+
+	s := &registry.Service{}
+
+	for _, n := range rsp.Node.Nodes {
+		if n.Dir {
+			continue
+		}
+		sn := decode(n.Value)
+		for _, node := range sn.Nodes {
+			s.Nodes = append(s.Nodes, node)
+		}
+	}
+
+	return s, nil
+}
+
+func (e *etcdRegistry) ListServices() ([]*registry.Service, error) {
+	e.RLock()
+	serviceMap := e.services
+	e.RUnlock()
+
+	var services []*registry.Service
+
+	if len(serviceMap) > 0 {
+		for _, service := range services {
+			services = append(services, service)
+		}
+		return services, nil
+	}
+
+	rsp, err := e.client.Get(prefix, true, true)
+	if err != nil && !strings.HasPrefix(err.Error(), "100: Key not found") {
+		return nil, err
+	}
+
+	for _, node := range rsp.Node.Nodes {
+		service := &registry.Service{}
+
+		for _, n := range node.Nodes {
+			i := decode(n.Value)
+			service.Name = i.Name
+			for _, in := range i.Nodes {
+				service.Nodes = append(service.Nodes, in)
+			}
+		}
+
+		services = append(services, service)
+	}
+
+	return services, nil
+}
+
+func (e *etcdRegistry) Watch() {
+	newEtcdWatcher(e)
+}
+
+func NewRegistry(addrs []string, opt ...registry.Option) registry.Registry {
+	var cAddrs []string
+
+	for _, addr := range addrs {
+		if len(addr) == 0 {
+			continue
+		}
+		cAddrs = append(cAddrs, addr)
+	}
+
+	if len(cAddrs) == 0 {
+		cAddrs = []string{"http://127.0.0.1:2379"}
+	}
+
+	e := &etcdRegistry{
+		client:   etcd.NewClient(cAddrs),
+		services: make(map[string]*registry.Service),
+	}
+
+	// Need to fix watcher
+	// e.Watch()
+
+	return e
+}

registry/etcd/watcher.go

@@ -0,0 +1,73 @@
+package etcd
+
+import (
+	"github.com/coreos/go-etcd/etcd"
+	"github.com/myodc/go-micro/registry"
+)
+
+type etcdWatcher struct {
+	registry *etcdRegistry
+	stop     chan bool
+}
+
+func newEtcdWatcher(r *etcdRegistry) *etcdWatcher {
+	ew := &etcdWatcher{
+		registry: r,
+		stop:     make(chan bool),
+	}
+
+	ch := make(chan *etcd.Response)
+
+	go r.client.Watch(prefix, 0, true, ch, ew.stop)
+
+	go func() {
+		for rsp := range ch {
+			if rsp.Node.Dir {
+				continue
+			}
+
+			s := decode(rsp.Node.Value)
+			if s == nil {
+				continue
+			}
+
+			r.Lock()
+
+			service, ok := r.services[s.Name]
+			if !ok {
+				if rsp.Action == "create" {
+					r.services[s.Name] = s
+				}
+				r.Unlock()
+				continue
+			}
+
+			switch rsp.Action {
+			case "delete":
+				var nodes []*registry.Node
+				for _, node := range service.Nodes {
+					var seen bool
+					for _, n := range s.Nodes {
+						if node.Id == n.Id {
+							seen = true
+							break
+						}
+					}
+					if !seen {
+						nodes = append(nodes, node)
+					}
+				}
+				service.Nodes = nodes
+			case "create":
+				service.Nodes = append(service.Nodes, s.Nodes...)
+			}
+			r.Unlock()
+		}
+	}()
+
+	return ew
+}
+
+func (ew *etcdWatcher) Stop() {
+	ew.stop <- true
+}