The test above concerts the case where a single pod is deleted using kubectl on a single node Kubernetes setup. the Endpoint object and more advanced abstractions such as Endpoint Slices ). Once the preStop hook completes, the kubelet on the node will issue the TERM signal to the running application in the containers of the pod. Even if you are using the preStop hook, it is important that you test what happens to your application if you send it a SIGTERM signal, so you are not surprised in production! Judging by documentation about preStop hook behavior it should work perfectly fine: This hook is called immediately before a container is terminated due to an API request or management event such as liveness probe failure, preemption, resource contention and others. The behavior is similar for a PreStop hook. If the preStop hook is still running after the grace period expires, the kubelet requests a small, one-off grace period extension of 2 seconds. Kubernetes sends the postStart event immediately after a Container is started, and it sends the preStop event immediately before the Container is terminated. After receiving the request, the API server updates the deletiontimestamp and deletiongraceperiodseconds in the pod. In reference to a Kubernetes Cluster, applications reside in pods, which are the smallest deployable units of computing that you can create and manage in Kubernetes… In order to understand the working principle of prestop hook, let’s explain itPodExit process for. By default, this is 30 seconds. After grace period is exceeded, kubelet sends sigkill to kill the containers that have not yet exited. If the running time of prestop hook exceeds grace period, kubelet will send SIGTERM and wait another 2 seconds. It is a good idea to test what would happen in a multi-node Kubernetes setup, when one of the nodes is terminated. This did not change the behavior either. Kubernetes supports the postStart and preStop events. This page shows how to attach handlers to Container lifecycle events. Pod enters the terminating state; Pod will stop processing. We could use the Kubernetes container hooks to implement a PreStop hook to do something before Kubernetes attempts to stop the container. However, if the hook takes a while to run or hangs, the container will never reach a "running" state. The preStop hook is executed inside the container and blocks the termination process in Kubernetes until the grace period is over. If a PostStart or PreStop hook fails, it will kill the container. Kubernetes offers robust primitives to distribute the endpoints (i.e. But Kubernetes doesn't work like that. At the same time, kubelet sends SIGTERM to the container without prestop hook. If the hook hangs during execution, the Pod phase will stay in a "running" state and never reach "failed." We knew that straight killing the node parent was bad, even if it was graceful, so we experimented with … Future work. However, Kubernetes does not verify that the components that subscribe to endpoints changes are … 4 - Kubernetes waits for a grace period At this point, Kubernetes waits for a specified time called the termination grace period. 2.4.