Add live list of pods to PVC protection controller, as opposed to doing
only a cache-based list through the Informer. Both lists are performed
while processing a PVC with deletionTimestamp set to check whether Pods
using the PVC exist and remove the finalizer to enable deletion of the
PVC if that's not the case. Prior to this commit only the cache-based
list was done but that's unreliable because a pod using the PVC might
exist but not be in the cache just yet. On the other hand, the live
list is 100% reliable.
Note that it would be enough to do only the live list. Instead, this
commit adds it after the cache-based list and performs it only if the
latter finds no Pod blocking deletion of the PVC being processed. The
rationale is that live lists are expensive and it's desirable to
minimize them. The drawback is that if at the time of the cache-based
list the cache has not been notified yet of the deletion of a Pod using
the PVC the PVC is kept. Correctness is not compromised because the
finalizer will be removed when the Pod deletion notification is
received, but this means PVC deletion is delayed. Reducing live lists
was valued more than deleting PVCs slightly faster.
Also, add a unit test that fails without the change introduced by this
commit and revamp old unit tests. The latter is needed because expected
behavior is described in terms of API calls the controller makes, and
this commit introduces new API calls (the live lists).
before this change, an object would be added to `attemptToDelete` queue only if `gc` detected the transition, simply by check if `deletionTimestamp` was set. After the change, it will check if `foregroundDeletion` finalizer has been set before adding the item to the queue.
During a Deployment update there may be more Pods in the scale target
ref status than in the spec. This test verifies that we do not scale
to the status value. Instead we should stay at the spec value.
Fails before #79035 and passes after.
This is used when the cloudprovider layer is not implementing loadBalancer service.
Implementation will be in a different controller running on master.
Make the PVC protection controller robust to cases where a Pod X is deleted,
then a Pod Y with the same namespaced name is created and the two events are
delivered via a single update notification. Both pods should be processed,
because X might be blocking deletion of a PVC which is not referenced by Y.
Prior to this commit only the newer pod is processed, which means that it
is possible to leak PVCs.
Also, add unit tests to reflect the change.
