The sync loop should check for terminated pods that are no longer
running and clear them. The status loop should never write status
if the pod UID changes. Mirror pods should be deleted immediately
rather than gracefully.
Avoid TTL by deleting pods immediately when they aren't
scheduled, and letting the Kubelet delete them otherwise.
Ensure the Kubelet uses pod.Spec.TerminationGracePeriodSeconds
when no pod.DeletionGracePeriodSeconds is available.
Since it takes a while (1-2mins) for kubelet to pulling a big image
(>500MB). Just showing "Pending" for pod status is not very helpful.
This commit introduces a "pulling" event, and inserts it before the
kubelet starts to pull an image.
If a pod was deleted and the associated volumes/directory were removed, there
could be a window where the pod worker is still active. If the pod worker tries
to inspect the logs, such an error would be logged. Since the pod has been
deleted, such error messages are meaningless.
This change stops logging this error, but stores the error string in the pod
status. The pod status will be updated for pods that are still alive, and will
be discarded eventually for deleted pods.
This commit wires together the graceful delete option for pods
on the Kubelet. When a pod is deleted on the API server, a
grace period is calculated that is based on the
Pod.Spec.TerminationGracePeriodInSeconds, the user's provided grace
period, or a default. The grace period can only shrink once set.
The value provided by the user (or the default) is set onto metadata
as DeletionGracePeriod.
When the Kubelet sees a pod with DeletionTimestamp set, it uses the
value of ObjectMeta.GracePeriodSeconds as the grace period
sent to Docker. When updating status, if the pod has DeletionTimestamp
set and all containers are terminated, the Kubelet will update the
status one last time and then invoke Delete(pod, grace: 0) to
clean up the pod immediately.
Add support for pluggable Docker exec handlers. The default handler is
now Docker's native exec API call. The previous default, nsenter, can be
selected by passing --docker-exec-handler=nsenter when starting the
kubelet.
