Automatic merge from submit-queue
Volume manager must verify containers terminated before deleting for ungracefully terminated pods
A pod is removed from volume manager (triggering unmount) when it is deleted from the kubelet pod manager. Kubelet deletes the pod from pod manager as soon as it receives a delete pod request. As long as the graceful termination period is non-zero, this happens after kubelet has terminated all containers for the pod. However, when graceful termination period for a pod is set to zero, the volume is deleted from pod manager *before* its containers are terminated.
This can result in volumes getting unmounted from a pod before all containers have exited when graceful termination is set to zero.
This PR prevents that from happening by only deleting a volume from volume manager once it is deleted from the pod manager AND the kubelet containerRuntime status indicates all containers for the pod have exited. Because we do not want to call containerRuntime too frequently, we introduce a delay in the `findAndRemoveDeletedPods()` method to prevent it from executing more frequently than every two seconds.
Fixes https://github.com/kubernetes/kubernetes/issues/27691
Running test in tight loop to verify fix.
Ensure that kublet marks VolumeInUse before checking if it is Attached.
Also ensures that the attach/detach controller always fetches a fresh
copy of the node object before detach (instead ofKubelet relying on node
informer cache).
Modify attach/detach controller to keep track of volumes to report
attached in Node VolumeToAttach status.
Modify kubelet volume manager to wait for volume to show up in Node
VolumeToAttach status.
Implement exponential backoff for errors in volume manager and attach
detach controller
If the mount operation exceeds the timeout, it will return an error and the
pod worker will retry in the next sync (10s or less). Compared with the
original value (i.e., 10 minutes), this frees the pod worker sooner to process
pod updates, if there are any.
This commit adds a new volume manager in kubelet that synchronizes
volume mount/unmount (and attach/detach, if attach/detach controller
is not enabled).
This eliminates the race conditions between the pod creation loop
and the orphaned volumes loops. It also removes the unmount/detach
from the `syncPod()` path so volume clean up never blocks the
`syncPod` loop.
