specify pod name and hostname in indexed job

pkg/controller/job/indexed_job_utils.go

@@ -26,6 +26,7 @@ import (
 	batch "k8s.io/api/batch/v1"
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/apiserver/pkg/storage/names"
 	"k8s.io/kubernetes/pkg/controller"
 )
 
@@ -216,6 +217,15 @@ func addCompletionIndexAnnotation(template *v1.PodTemplateSpec, index int) {
 	template.Annotations[batch.JobCompletionIndexAnnotation] = strconv.Itoa(index)
 }
 
+func podGenerateNameWithIndex(jobName string, index int) string {
+	appendIndex := "-" + strconv.Itoa(index) + "-"
+	generateNamePrefix := jobName + appendIndex
+	if len(generateNamePrefix) > names.MaxGeneratedNameLength {
+		generateNamePrefix = generateNamePrefix[:names.MaxGeneratedNameLength-len(appendIndex)] + appendIndex
+	}
+	return generateNamePrefix
+}
+
 type byCompletionIndex []*v1.Pod
 
 func (bci byCompletionIndex) Less(i, j int) bool {

pkg/controller/job/indexed_job_utils_test.go

@@ -269,6 +269,38 @@ func TestAppendDuplicatedIndexPodsForRemoval(t *testing.T) {
 	}
 }
 
+func TestPodGenerateNameWithIndex(t *testing.T) {
+	cases := map[string]struct {
+		jobname             string
+		index               int
+		wantPodGenerateName string
+	}{
+		"short job name": {
+			jobname:             "indexed-job",
+			index:               1,
+			wantPodGenerateName: "indexed-job-1-",
+		},
+		"job name exceeds MaxGeneneratedNameLength": {
+			jobname:             "hhhhhooooohhhhhooooohhhhhooooohhhhhooooohhhhhooooohhhhhooooohhhhhooooo",
+			index:               1,
+			wantPodGenerateName: "hhhhhooooohhhhhooooohhhhhooooohhhhhooooohhhhhooooohhhhh-1-",
+		},
+		"job name with index suffix exceeds MaxGeneratedNameLength": {
+			jobname:             "hhhhhooooohhhhhooooohhhhhooooohhhhhooooohhhhhooooohhhhhoo",
+			index:               1,
+			wantPodGenerateName: "hhhhhooooohhhhhooooohhhhhooooohhhhhooooohhhhhooooohhhhh-1-",
+		},
+	}
+	for name, tc := range cases {
+		t.Run(name, func(t *testing.T) {
+			podGenerateName := podGenerateNameWithIndex(tc.jobname, tc.index)
+			if diff := cmp.Equal(tc.wantPodGenerateName, podGenerateName); !diff {
+				t.Errorf("Got pod generateName %s, want %s", podGenerateName, tc.wantPodGenerateName)
+			}
+		})
+	}
+}
+
 func hollowPodsWithIndexPhase(descs []indexPhase) []*v1.Pod {
 	pods := make([]*v1.Pod, 0, len(descs))
 	for _, desc := range descs {

pkg/controller/job/job_controller.go

@@ -871,9 +871,11 @@ func (jm *Controller) manageJob(job *batch.Job, activePods []*v1.Pod, succeeded
 					if completionIndex != unknownCompletionIndex {
 						template = podTemplate.DeepCopy()
 						addCompletionIndexAnnotation(template, completionIndex)
+						template.Spec.Hostname = fmt.Sprintf("%s-%d", job.Name, completionIndex)
 					}
 					defer wait.Done()
-					err := jm.podControl.CreatePodsWithControllerRef(job.Namespace, template, job, metav1.NewControllerRef(job, controllerKind))
+					generateName := podGenerateNameWithIndex(job.Name, completionIndex)
+					err := jm.podControl.CreatePodsWithControllerRefAndGenerateName(job.Namespace, template, job, metav1.NewControllerRef(job, controllerKind), generateName)
 					if err != nil {
 						if apierrors.HasStatusCause(err, v1.NamespaceTerminatingCause) {
 							// If the namespace is being torn down, we can safely ignore

pkg/controller/job/job_controller_test.go

@@ -151,6 +151,7 @@ func setPodsStatusesWithIndexes(podIndexer cache.Indexer, job *batch.Job, status
 			p.Annotations = map[string]string{
 				batch.JobCompletionIndexAnnotation: s.Index,
 			}
+			p.Spec.Hostname = fmt.Sprintf("%s-%s", job.Name, s.Index)
 		}
 		podIndexer.Add(p)
 	}
@@ -735,7 +736,7 @@ func TestControllerSyncJob(t *testing.T) {
 				t.Errorf("Unexpected number of creates.  Expected %d, saw %d\n", tc.expectedCreations, len(fakePodControl.Templates))
 			}
 			if tc.completionMode == batch.IndexedCompletion {
-				checkCompletionIndexesInPods(t, &fakePodControl, tc.expectedCreatedIndexes)
+				checkIndexedJobPods(t, &fakePodControl, tc.expectedCreatedIndexes, job.Name)
 			}
 			if int32(len(fakePodControl.DeletePodName)) != tc.expectedDeletions {
 				t.Errorf("Unexpected number of deletes.  Expected %d, saw %d\n", tc.expectedDeletions, len(fakePodControl.DeletePodName))
@@ -806,7 +807,7 @@ func TestControllerSyncJob(t *testing.T) {
 	}
 }
 
-func checkCompletionIndexesInPods(t *testing.T, control *controller.FakePodControl, wantIndexes sets.Int) {
+func checkIndexedJobPods(t *testing.T, control *controller.FakePodControl, wantIndexes sets.Int, jobName string) {
 	t.Helper()
 	gotIndexes := sets.NewInt()
 	for _, p := range control.Templates {
@@ -817,6 +818,10 @@ func checkCompletionIndexesInPods(t *testing.T, control *controller.FakePodContr
 		} else {
 			gotIndexes.Insert(ix)
 		}
+		expectedName := fmt.Sprintf("%s-%d", jobName, ix)
+		if diff := cmp.Equal(expectedName, p.Spec.Hostname); !diff {
+			t.Errorf("Got pod hostname %s, want %s", p.Spec.Hostname, expectedName)
+		}
 	}
 	if diff := cmp.Diff(wantIndexes.List(), gotIndexes.List()); diff != "" {
 		t.Errorf("Unexpected created completion indexes (-want,+got):\n%s", diff)