Merge pull request #7742 from cjcullen/cbr0

Make changes suggested in #7675

cluster/addons/dns/kube2sky/kube2sky.go

@@ -34,6 +34,7 @@ import (
 	kfields "github.com/GoogleCloudPlatform/kubernetes/pkg/fields"
 	klabels "github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
 	tools "github.com/GoogleCloudPlatform/kubernetes/pkg/tools"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/util/wait"
 	kwatch "github.com/GoogleCloudPlatform/kubernetes/pkg/watch"
 	etcd "github.com/coreos/go-etcd/etcd"
 	skymsg "github.com/skynetservices/skydns/msg"
@@ -121,24 +122,21 @@ func newEtcdClient() (client *etcd.Client) {
 		}
 	}
 	// loop until we have > 0 machines && machines[0] != ""
-	timeout := false
-	go func() {
-		<-time.After(10 * time.Second)
-		timeout = true
-	}()
-	for !timeout {
-		client = etcd.NewClient([]string{*etcd_server})
-		if client == nil {
-			return nil
+	poll, timeout := 1*time.Second, 10*time.Second
+	if err := wait.Poll(poll, timeout, func() (bool, error) {
+		if client = etcd.NewClient([]string{*etcd_server}); client == nil {
+			log.Fatal("etcd.NewClient returned nil")
 		}
 		client.SyncCluster()
 		machines := client.GetCluster()
-		if len(machines) > 0 && len(machines[0]) > 0 {
-			return client
+		if len(machines) == 0 || len(machines[0]) == 0 {
+			return false, nil
 		}
+		return true, nil
+	}); err != nil {
+		log.Fatalf("Timed out after %s waiting for at least 1 synchronized etcd server in the cluster", timeout)
 	}
-	log.Fatal("Timed out waiting for correct response from etcd server")
-	return nil
+	return client
 }
 
 // TODO: evaluate using pkg/client/clientcmd

cluster/addons/dns/skydns-rc.yaml.in

@@ -31,7 +31,7 @@ desiredState:
                     "-initial-cluster-token=skydns-etcd",
             ]
           - name: kube2sky
-            image: gcr.io/google_containers/kube2sky:1.3
+            image: gcr.io/google_containers/kube2sky:1.4
             volumeMounts:
                - name: dns-token
                  mountPath: /etc/dns_token

pkg/tools/etcd_helper.go

@@ -517,7 +517,7 @@ func GetEtcdVersion(host string) (string, error) {
 	}
 	defer response.Body.Close()
 	if response.StatusCode != http.StatusOK {
-		return "", fmt.Errorf("Unsuccessful response from server: %v", err)
+		return "", fmt.Errorf("unsuccessful response from etcd server %q: %v", host, err)
 	}
 	versionBytes, err := ioutil.ReadAll(response.Body)
 	if err != nil {

pkg/tools/etcd_helper_test.go

@@ -35,6 +35,8 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+const validEtcdVersion = "etcd 2.0.9"
+
 type TestResource struct {
 	api.TypeMeta   `json:",inline"`
 	api.ObjectMeta `json:"metadata"`
@@ -685,7 +687,7 @@ func TestGuaranteedUpdate_CreateCollision(t *testing.T) {
 
 func TestGetEtcdVersion_ValidVersion(t *testing.T) {
 	testServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		fmt.Fprint(w, "etcd 2.0.9")
+		fmt.Fprint(w, validEtcdVersion)
 	}))
 	defer testServer.Close()
 
@@ -694,7 +696,7 @@ func TestGetEtcdVersion_ValidVersion(t *testing.T) {
 	if version, err = GetEtcdVersion(testServer.URL); err != nil {
 		t.Errorf("Unexpected error: %v", err)
 	}
-	assert.Equal(t, "etcd 2.0.9", version, "Unexpected version")
+	assert.Equal(t, validEtcdVersion, version, "Unexpected version")
 	assert.Nil(t, err)
 }