Let Kubernetes generate job names

pkg/controller/cronjobber/controller.go

@@ -330,7 +330,7 @@ func syncOne(sj *cronjobberv1.TZCronJob, js []batchv1.Job, now time.Time, jc job
 		}
 	}
 
-	jobReq, err := getJobFromTemplate(sj, scheduledTime)
+	jobReq, err := getJobFromTemplate(sj)
 	if err != nil {
 		logger.Errorf("Unable to make Job from template in %s: %v", nameForLog, err)
 		return

pkg/controller/cronjobber/controller_test.go

@@ -18,6 +18,7 @@ limitations under the License.
 package cronjobber
 
 import (
+	"fmt"
 	"strconv"
 	"strings"
 	"testing"
@@ -271,7 +272,7 @@ func TestSyncOne_RunOrNot(t *testing.T) {
 		if tc.ranPreviously {
 			sj.ObjectMeta.CreationTimestamp = metav1.Time{Time: justBeforeThePriorHour()}
 			sj.Status.LastScheduleTime = &metav1.Time{Time: justAfterThePriorHour()}
-			job, err = getJobFromTemplate(&sj, sj.Status.LastScheduleTime.Time)
+			job, err = getJobFromTemplate(&sj)
 			if err != nil {
 				t.Fatalf("%s: nexpected error creating a job from template: %v", name, err)
 			}
@@ -522,13 +523,14 @@ func TestCleanupFinishedJobs_DeleteOrNot(t *testing.T) {
 		sj.Status.Active = []v1.ObjectReference{}
 
 		for i, spec := range tc.jobSpecs {
-			job, err = getJobFromTemplate(&sj, startTimeStringToTime(spec.StartTime))
+			job, err = getJobFromTemplate(&sj)
 			if err != nil {
 				t.Fatalf("%s: unexpected error creating a job from template: %v", name, err)
 			}
 
 			job.UID = types.UID(strconv.Itoa(i))
 			job.Namespace = ""
+			job.Name = fmt.Sprintf("%s-%d", sj.Name, i)
 
 			if spec.IsFinished {
 				var conditionType batchv1.JobConditionType

pkg/controller/cronjobber/utils.go

@@ -149,29 +149,22 @@ func getRecentUnmetScheduleTimes(sj cronjobberv1.TZCronJob, now time.Time) ([]ti
 }
 
 // getJobFromTemplate makes a Job from a CronJob
-func getJobFromTemplate(sj *cronjobberv1.TZCronJob, scheduledTime time.Time) (*batchv1.Job, error) {
+func getJobFromTemplate(sj *cronjobberv1.TZCronJob) (*batchv1.Job, error) {
 	labels := copyLabels(&sj.Spec.JobTemplate)
 	annotations := copyAnnotations(&sj.Spec.JobTemplate)
-	// We want job names for a given nominal start time to have a deterministic name to avoid the same job being created twice
-	name := fmt.Sprintf("%s-%d", sj.Name, getTimeHash(scheduledTime))
 
 	job := &batchv1.Job{
 		ObjectMeta: metav1.ObjectMeta{
 			Labels:          labels,
 			Annotations:     annotations,
-			Name:            name,
+			GenerateName:    sj.Name,
 			OwnerReferences: []metav1.OwnerReference{*metav1.NewControllerRef(sj, controllerKind)},
 		},
 		Spec: sj.Spec.JobTemplate.Spec,
 	}
 	return job, nil
 }
 
-// getTimeHash returns Unix Epoch Time
-func getTimeHash(scheduledTime time.Time) int64 {
-	return scheduledTime.Unix()
-}
-
 func getFinishedStatus(j *batchv1.Job) (bool, batchv1.JobConditionType) {
 	for _, c := range j.Status.Conditions {
 		if (c.Type == batchv1.JobComplete || c.Type == batchv1.JobFailed) && c.Status == v1.ConditionTrue {

pkg/controller/cronjobber/utils_test.go

@@ -18,7 +18,6 @@ limitations under the License.
 package cronjobber
 
 import (
-	"strings"
 	"testing"
 	"time"
 
@@ -77,11 +76,11 @@ func TestGetJobFromTemplate(t *testing.T) {
 	}
 
 	var job *batchv1.Job
-	job, err := getJobFromTemplate(&sj, time.Time{})
+	job, err := getJobFromTemplate(&sj)
 	if err != nil {
 		t.Errorf("Did not expect error: %s", err)
 	}
-	if !strings.HasPrefix(job.ObjectMeta.Name, "mycronjob-") {
+	if job.ObjectMeta.GenerateName != "mycronjob" {
 		t.Errorf("Wrong Name")
 	}
 	if len(job.ObjectMeta.Labels) != 1 {