Move GetClusterZones() to e2enode

test/e2e/framework/node/resource.go

@@ -471,3 +471,24 @@ func PodNodePairs(c clientset.Interface, ns string) ([]PodNode, error) {
 
 	return result, nil
 }
+
+// GetClusterZones returns the values of zone label collected from all nodes.
+func GetClusterZones(c clientset.Interface) (sets.String, error) {
+	nodes, err := c.CoreV1().Nodes().List(context.TODO(), metav1.ListOptions{})
+	if err != nil {
+		return nil, fmt.Errorf("Error getting nodes while attempting to list cluster zones: %v", err)
+	}
+
+	// collect values of zone label from all nodes
+	zones := sets.NewString()
+	for _, node := range nodes.Items {
+		if zone, found := node.Labels[v1.LabelZoneFailureDomain]; found {
+			zones.Insert(zone)
+		}
+
+		if zone, found := node.Labels[v1.LabelZoneFailureDomainStable]; found {
+			zones.Insert(zone)
+		}
+	}
+	return zones, nil
+}