Automatic merge from submit-queue
Fix mount collision timeout issue
Short- or medium-term workaround for #29555. The root issue being fixed here is that the recent attach/detach work in the kubelet uses a unique volume name as a key that tracks the work that has to be done for each volume in a pod to attach/mount/umount/detach. However, the non-attachable volume plugins do not report unique names for themselves, which causes collisions when a single secret or configmap is mounted multiple times in a pod.
This is still a WIP -- I need to add a couple E2E tests that ensure that tests break in the future if there is a regression -- but posting for early review.
cc @kubernetes/sig-storage
Ultimately, I would like to refine this a bit further. A couple things I would like to change:
1. `GetUniqueVolumeName` should be a property ONLY of attachable volumes
2. I would like to see the kubelet apparatus for attach/mount/umount/detach handle non-attachable volumes specifically to avoid things like the `WaitForControllerAttach` call that has to be done for those volume types now
For non-attachable volumes, do not call GetVolumeName on the plugin and instead
generate a unique name based on the identity of the pod and the name of the volume
within the pod.
This fixes race conditions in configmap, secret, downwardapi & git_repo
volume plugins.
wrappedVolumeSpec vars used by volume mounters and unmounters contained
a pointer to api.Volume structs which were being patched by
NewWrapperMounter/NewWrapperUnmounter, causing race condition during
volume mounts.
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.
- Add volume.MetricsProvider function to Volume interface.
- Add volume.MetricsDu for providing metrics via executing "du".
- Add volulme.MetricsNil for unsupported Volumes.
