Merge pull request #6289 from purpleidea/feat/move-readynotify

embed: Move the ReadyNotify() call to a more sane place

embed/doc.go

@@ -19,6 +19,7 @@ Launch an embedded etcd server using the configuration defaults:
 
 	import (
 		"log"
+		"time"
 
 		"github.com/coreos/etcd/embed"
 	)
@@ -31,6 +32,13 @@ Launch an embedded etcd server using the configuration defaults:
 			log.Fatal(err)
 		}
 		defer e.Close()
+		select {
+		case <-e.Server.ReadyNotify():
+			log.Printf("Server is ready!")
+		case <-time.After(60 * time.Second):
+			e.Server.Stop() // trigger a shutdown
+			log.Printf("Server took too long to start!")
+		}
 		log.Fatal(<-e.Err())
 	}
 */

embed/etcd.go

@@ -59,6 +59,8 @@ type Etcd struct {
 }
 
 // StartEtcd launches the etcd server and HTTP handlers for client/server communication.
+// The returned Etcd.Server is not guaranteed to have joined the cluster. Wait
+// on the Etcd.Server.ReadyNotify() channel to know when it completes and is ready for use.
 func StartEtcd(inCfg *Config) (e *Etcd, err error) {
 	if err = inCfg.Validate(); err != nil {
 		return nil, err
@@ -130,7 +132,6 @@ func StartEtcd(inCfg *Config) (e *Etcd, err error) {
 	if err = e.serve(); err != nil {
 		return
 	}
-	<-e.Server.ReadyNotify()
 	return
 }
 

etcdmain/etcd.go

@@ -202,6 +202,7 @@ func startEtcd(cfg *embed.Config) (<-chan struct{}, <-chan error, error) {
 		return nil, nil, err
 	}
 	osutil.RegisterInterruptHandler(e.Server.Stop)
+	<-e.Server.ReadyNotify() // wait for e.Server to join the cluster
 	return e.Server.StopNotify(), e.Err(), nil
 }
 

integration/embed_test.go

@@ -65,6 +65,9 @@ func TestEmbedEtcd(t *testing.T) {
 	for i, tt := range tests {
 		tests[i].cfg.Dir = dir
 		e, err := embed.StartEtcd(&tests[i].cfg)
+		if e != nil {
+			<-e.Server.ReadyNotify() // wait for e.Server to join the cluster
+		}
 		if tt.werr != "" {
 			if err == nil || !strings.Contains(err.Error(), tt.werr) {
 				t.Errorf("%d: expected error with %q, got %v", i, tt.werr, err)