CronJob: Apply missing ControllerRefs to Jobs created by a CronJob.

This should only happen if the Jobs were created by an older version
of the CronJob controller, since from now on we add ControllerRef upon
creation.

CronJob doesn't do actual adoption because it doesn't use label
selectors to find its Jobs. However, we should apply ControllerRef
for potential server-side cascading deletion, and to advise other
controllers we own these objects.

pkg/controller/cronjob/utils_test.go

@@ -26,6 +26,7 @@ import (
 	"k8s.io/kubernetes/pkg/api/v1"
 	batchv1 "k8s.io/kubernetes/pkg/apis/batch/v1"
 	batchv2alpha1 "k8s.io/kubernetes/pkg/apis/batch/v2alpha1"
+	"k8s.io/kubernetes/pkg/controller"
 )
 
 func TestGetJobFromTemplate(t *testing.T) {
@@ -366,5 +367,30 @@ func TestGetRecentUnmetScheduleTimes(t *testing.T) {
 			t.Errorf("unexpected error")
 		}
 	}
-
+}
+
+func TestAdoptJobs(t *testing.T) {
+	sj := cronJob()
+	jc := &fakeJobControl{}
+	jobs := []batchv1.Job{newJob("uid0"), newJob("uid1")}
+	jobs[0].OwnerReferences = nil
+	jobs[0].Name = "job0"
+	jobs[1].OwnerReferences = []metav1.OwnerReference{*newControllerRef(&sj)}
+	jobs[1].Name = "job1"
+
+	if err := adoptJobs(&sj, jobs, jc); err != nil {
+		t.Errorf("adoptJobs() error: %v", err)
+	}
+	for i := range jobs {
+		controllerRef := controller.GetControllerOf(&jobs[i])
+		if controllerRef == nil {
+			t.Errorf("Job should have ControllerRef: %#v", jobs[i])
+		}
+	}
+	if got, want := len(jc.UpdateJobName), 1; got != want {
+		t.Errorf("len(UpdateJobName) = %v, want %v", got, want)
+	}
+	if got, want := jc.UpdateJobName[0], "job0"; got != want {
+		t.Errorf("UpdateJobName = %v, want %v", got, want)
+	}
 }