pkg/*: Fix long cluster names causing pods to hang

This patch restricts the name of the cluster to less than 52 characters. This simpler approach is preferred so it can be documented. Operator log displays appropriate error for users.

Fixes #1994

pkg/cluster/cluster.go

@@ -87,6 +87,9 @@ type Cluster struct {
 
 func New(config Config, cl *api.EtcdCluster) *Cluster {
 	lg := logrus.WithField("pkg", "cluster").WithField("cluster-name", cl.Name).WithField("cluster-namespace", cl.Namespace)
+	if len(cl.Name) > k8sutil.MaxNameLength || len(cl.ClusterName) > k8sutil.MaxNameLength {
+		return nil
+	}
 
 	c := &Cluster{
 		logger:    lg,

pkg/cluster/cluster_test.go

@@ -56,3 +56,19 @@ func TestUpdateEventUpdateLocalClusterObj(t *testing.T) {
 		t.Errorf("expect version=%s, get=%s", newVersion, c.cluster.ResourceVersion)
 	}
 }
+
+func TestNewLongClusterName(t *testing.T) {
+	clus := &api.EtcdCluster{
+		TypeMeta: metav1.TypeMeta{
+			APIVersion: api.SchemeGroupVersion.String(),
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "example-etcd-cluster123456789123456789123456789123456789123456",
+			Namespace: metav1.NamespaceDefault,
+		},
+	}
+	clus.SetClusterName("example-etcd-cluster123456789123456789123456789123456789123456")
+	if c := New(Config{}, clus); c != nil {
+		t.Errorf("expect c to be nil")
+	}
+}

pkg/controller/controller.go

@@ -92,7 +92,9 @@ func (c *Controller) handleClusterEvent(event *Event) (bool, error) {
 		}
 
 		nc := cluster.New(c.makeClusterConfig(), clus)
-
+		if nc == nil {
+			return false, fmt.Errorf("cluster name cannot be more than %v characters long, please delete the CR\n", k8sutil.MaxNameLength)
+		}
 		c.clusters[getNamespacedName(clus)] = nc
 
 		clustersCreated.Inc()

pkg/controller/controller_test.go

@@ -159,3 +159,24 @@ func TestHandleClusterEventNamespacedIgnored(t *testing.T) {
 		t.Errorf("cluster should be ignored")
 	}
 }
+
+func TestHandleClusterEventWithLongClusterName(t *testing.T) {
+	c := New(Config{})
+
+	clus := &api.EtcdCluster{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "example-etcd-cluster123456789123456789123456789123456789123456",
+		},
+	}
+	e := &Event{
+		Type:   watch.Added,
+		Object: clus,
+	}
+	if ignored, err := c.handleClusterEvent(e); !ignored {
+		if err == nil {
+			t.Errorf("err should not be nil")
+		}
+	} else {
+		t.Errorf("cluster should not be ignored")
+	}
+}

pkg/util/k8sutil/k8sutil.go

@@ -59,7 +59,7 @@ const (
 
 	randomSuffixLength = 10
 	// k8s object name has a maximum length
-	maxNameLength = 63 - randomSuffixLength - 1
+	MaxNameLength = 63 - randomSuffixLength - 1
 
 	defaultBusyboxImage = "busybox:1.28.0-glibc"
 
@@ -517,8 +517,8 @@ func mergeLabels(l1, l2 map[string]string) {
 
 func UniqueMemberName(clusterName string) string {
 	suffix := utilrand.String(randomSuffixLength)
-	if len(clusterName) > maxNameLength {
-		clusterName = clusterName[:maxNameLength]
+	if len(clusterName) > MaxNameLength {
+		clusterName = clusterName[:MaxNameLength]
 	}
 	return clusterName + "-" + suffix
 }