feat: Append job creation timestamp to cronjob annotations (#118137)

* Append job name to job annotations

Signed-off-by: Heba Elayoty <hebaelayoty@gmail.com>

* Update annotation description, remove timezone, and fix time

Signed-off-by: Heba Elayoty <hebaelayoty@gmail.com>

* Remove unused ctx

Signed-off-by: Heba Elayoty <hebaelayoty@gmail.com>

* code review comments

Signed-off-by: Heba Elayoty <hebaelayoty@gmail.com>

* code review comments

Signed-off-by: Heba Elayoty <hebaelayoty@gmail.com>

* Add timezone back

Signed-off-by: Heba Elayoty <hebaelayoty@gmail.com>

---------

Signed-off-by: Heba Elayoty <hebaelayoty@gmail.com>

pkg/controller/cronjob/utils.go

@@ -21,14 +21,17 @@ import (
 	"time"
 
 	"github.com/robfig/cron/v3"
+	"k8s.io/utils/pointer"
 
 	batchv1 "k8s.io/api/batch/v1"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/labels"
 	"k8s.io/apimachinery/pkg/types"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/client-go/tools/record"
 	"k8s.io/klog/v2"
+	"k8s.io/kubernetes/pkg/features"
 )
 
 // Utilities for dealing with Jobs and CronJobs and time.
@@ -213,6 +216,16 @@ func getJobFromTemplate2(cj *batchv1.CronJob, scheduledTime time.Time) (*batchv1
 	// We want job names for a given nominal start time to have a deterministic name to avoid the same job being created twice
 	name := getJobName(cj, scheduledTime)
 
+	if utilfeature.DefaultFeatureGate.Enabled(features.CronJobsScheduledAnnotation) {
+
+		timeZoneLocation, err := time.LoadLocation(pointer.StringDeref(cj.Spec.TimeZone, ""))
+		if err != nil {
+			return nil, err
+		}
+		// Append job creation timestamp to the cronJob annotations. The time will be in RFC3339 form.
+		annotations[batchv1.CronJobScheduledTimestampAnnotation] = scheduledTime.In(timeZoneLocation).Format(time.RFC3339)
+	}
+
 	job := &batchv1.Job{
 		ObjectMeta: metav1.ObjectMeta{
 			Labels:            labels,