implement statefulset scale subresource

test/e2e/apps/statefulset.go

@@ -843,6 +843,43 @@ var _ = SIGDescribe("StatefulSet", func() {
 				return nil
 			}, framework.StatefulPodTimeout, 2*time.Second).Should(BeNil())
 		})
+
+		It("should have a working scale subresource", func() {
+			By("Creating statefulset " + ssName + " in namespace " + ns)
+			ss := framework.NewStatefulSet(ssName, ns, headlessSvcName, 1, nil, nil, labels)
+			sst := framework.NewStatefulSetTester(c)
+			sst.SetHttpProbe(ss)
+			ss, err := c.AppsV1beta1().StatefulSets(ns).Create(ss)
+			Expect(err).NotTo(HaveOccurred())
+			sst.WaitForRunningAndReady(*ss.Spec.Replicas, ss)
+			ss = sst.WaitForStatus(ss)
+
+			By("getting scale subresource")
+			scale := framework.NewStatefulSetScale(ss)
+			scaleResult := &apps.Scale{}
+			err = c.AppsV1beta1().RESTClient().Get().AbsPath("/apis/apps/v1beta1").Namespace(ns).Resource("statefulsets").Name(ssName).SubResource("scale").Do().Into(scale)
+			if err != nil {
+				framework.Failf("Failed to get scale subresource: %v", err)
+			}
+			Expect(scale.Spec.Replicas).To(Equal(int32(1)))
+			Expect(scale.Status.Replicas).To(Equal(int32(1)))
+
+			By("updating a scale subresource")
+			scale.ResourceVersion = "" //unconditionally update to 2 replicas
+			scale.Spec.Replicas = 2
+			err = c.AppsV1beta1().RESTClient().Put().AbsPath("/apis/apps/v1beta1").Namespace(ns).Resource("statefulsets").Name(ssName).SubResource("scale").Body(scale).Do().Into(scaleResult)
+			if err != nil {
+				framework.Failf("Failed to put scale subresource: %v", err)
+			}
+			Expect(scaleResult.Spec.Replicas).To(Equal(int32(2)))
+
+			By("verifying the statefulset Spec.Replicas was modified")
+			ss, err = c.AppsV1beta1().StatefulSets(ns).Get(ssName, metav1.GetOptions{})
+			if err != nil {
+				framework.Failf("Failed to get statefulset resource: %v", err)
+			}
+			Expect(*(ss.Spec.Replicas)).To(Equal(int32(2)))
+		})
 	})
 
 	framework.KubeDescribe("Deploy clustered applications [Feature:StatefulSet] [Slow]", func() {

test/e2e/framework/BUILD

@@ -101,6 +101,7 @@ go_library(
         "//vendor/google.golang.org/api/compute/v1:go_default_library",
         "//vendor/google.golang.org/api/googleapi:go_default_library",
         "//vendor/k8s.io/api/apps/v1beta1:go_default_library",
+        "//vendor/k8s.io/api/apps/v1beta2:go_default_library",
         "//vendor/k8s.io/api/authorization/v1beta1:go_default_library",
         "//vendor/k8s.io/api/batch/v1:go_default_library",
         "//vendor/k8s.io/api/core/v1:go_default_library",

test/e2e/framework/statefulset_utils.go

@@ -29,6 +29,7 @@ import (
 	. "github.com/onsi/gomega"
 
 	apps "k8s.io/api/apps/v1beta1"
+	appsV1beta2 "k8s.io/api/apps/v1beta2"
 	"k8s.io/api/core/v1"
 	apierrs "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/resource"
@@ -224,7 +225,7 @@ func (s *StatefulSetTester) Scale(ss *apps.StatefulSet, count int32) error {
 
 // UpdateReplicas updates the replicas of ss to count.
 func (s *StatefulSetTester) UpdateReplicas(ss *apps.StatefulSet, count int32) {
-	s.update(ss.Namespace, ss.Name, func(ss *apps.StatefulSet) { ss.Spec.Replicas = &count })
+	s.update(ss.Namespace, ss.Name, func(ss *apps.StatefulSet) { *(ss.Spec.Replicas) = count })
 }
 
 // Restart scales ss to 0 and then back to its previous number of replicas.
@@ -812,6 +813,23 @@ func NewStatefulSet(name, ns, governingSvcName string, replicas int32, statefulP
 	}
 }
 
+// NewStatefulSetScale creates a new StatefulSet scale subresource and returns it
+func NewStatefulSetScale(ss *apps.StatefulSet) *appsV1beta2.Scale {
+	return &appsV1beta2.Scale{
+		// TODO: Create a variant of ObjectMeta type that only contains the fields below.
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      ss.Name,
+			Namespace: ss.Namespace,
+		},
+		Spec: appsV1beta2.ScaleSpec{
+			Replicas: *(ss.Spec.Replicas),
+		},
+		Status: appsV1beta2.ScaleStatus{
+			Replicas: ss.Status.Replicas,
+		},
+	}
+}
+
 var statefulPodRegex = regexp.MustCompile("(.*)-([0-9]+)$")
 
 func getStatefulPodOrdinal(pod *v1.Pod) int {