Merge pull request #36022 from janetkuo/statefulset-e2e-hostname

Automatic merge from submit-queue

StatefulSet e2e: verify stateful pod hostname

cc @erictune @foxish @kubernetes/sig-apps

test/e2e/petset.go

@@ -125,11 +125,14 @@ var _ = framework.KubeDescribe("StatefulSet [Slow] [Feature:PetSet]", func() {
 			By("Verifying statefulset mounted data directory is usable")
 			ExpectNoError(pst.checkMount(ps, "/data"))
 
+			By("Verifying statefulset provides a stable hostname for each pod")
+			ExpectNoError(pst.checkHostname(ps))
+
 			cmd := "echo $(hostname) > /data/hostname; sync;"
 			By("Running " + cmd + " in all pets")
 			ExpectNoError(pst.execInPets(ps, cmd))
 
-			By("Restarting pet set " + ps.Name)
+			By("Restarting statefulset " + ps.Name)
 			pst.restart(ps)
 			pst.saturate(ps)
 
@@ -572,6 +575,20 @@ func (p *statefulSetTester) execInPets(ps *apps.StatefulSet, cmd string) error {
 	return nil
 }
 
+func (p *statefulSetTester) checkHostname(ps *apps.StatefulSet) error {
+	cmd := "printf $(hostname)"
+	podList := p.getPodList(ps)
+	for _, pet := range podList.Items {
+		hostname, err := framework.RunHostCmd(pet.Namespace, pet.Name, cmd)
+		if err != nil {
+			return err
+		}
+		if hostname != pet.Name {
+			return fmt.Errorf("unexpected hostname (%s) and stateful pod name (%s) not equal", hostname, pet.Name)
+		}
+	}
+	return nil
+}
 func (p *statefulSetTester) saturate(ps *apps.StatefulSet) {
 	// TODO: Watch events and check that creation timestamps don't overlap
 	var i int32