Merge pull request #47064 from Ritikaa96/annotation-restartedAt

Registering and Documenting restartedAt annotation

Author: k8s-ci-robot

content/en/docs/reference/labels-annotations-taints/_index.md

@@ -1275,6 +1275,25 @@ The kubectl command line tool uses this annotation as a legacy mechanism
 to track changes. That mechanism has been superseded by
 [Server-side apply](/docs/reference/using-api/server-side-apply/).
 
+### kubectl.kubernetes.io/restartedAt {#kubectl-k8s-io-restart-at}
+
+Type: Annotation
+
+Example: `kubectl.kubernetes.io/restartedAt: "2024-06-21T17:27:41Z"`
+
+Used on: Deployment, ReplicaSet, StatefulSet, DaemonSet, Pod
+
+This annotation contains the latest restart time of a resource (Deployment, ReplicaSet, StatefulSet or DaemonSet),
+where kubectl triggered a rollout in order to force creation of new Pods.
+The command `kubectl rollout restart <RESOURCE>` triggers a restart by patching the template
+metadata of all the pods of resource with this annotation. In above example the latest restart time is shown as 21st June 2024 at 17:27:41 UTC.
+
+You should not assume that this annotation represents the date / time of the most recent update;
+a separate change could have been made since the last manually triggered rollout.
+
+If you manually set this annotation on a Pod, nothing happens. The restarting side effect comes from
+how workload management and Pod templating works.
+
 ### endpoints.kubernetes.io/over-capacity
 
 Type: Annotation