Merge pull request #6966 from tengqm/prestop-hook

Document the limitation of preStop hook

docs/tasks/configure-pod-container/attach-handler-lifecycle-event.md

@@ -74,6 +74,11 @@ Kubernetes' management of the Container blocks until the preStop handler complet
 unless the Pod's grace period expires. For more details, see
 [Termination of Pods](/docs/user-guide/pods/#termination-of-pods).
 
+**Note**: Kubernetes only sends the preStop event when a Pod is *terminated*.
+This means that the preStop hook is not invoked when the Pod is *completed*. 
+This limitation is tracked in [issue #55087](https://github.com/kubernetes/kubernetes/issues/55807).
+{: .note}
+
 {% endcapture %}