In the API, the effect of the feature gate is that alpha fields get dropped on
create. They get preserved during updates if already set. The
PodSchedulingContext registration is *not* restricted by the feature gate.
This enables deleting stale PodSchedulingContext objects after disabling
the feature gate.
The scheduler checks the new feature gate before setting up an informer for
PodSchedulingContext objects and when deciding whether it can schedule a
pod. If any claim depends on a control plane controller, the scheduler bails
out, leading to:
Status: Pending
...
Warning FailedScheduling 73s default-scheduler 0/1 nodes are available: resourceclaim depends on disabled DRAControlPlaneController feature. no new claims to deallocate, preemption: 0/1 nodes are available: 1 Preemption is not helpful for scheduling.
The rest of the changes prepare for testing the new feature separately from
"structured parameters". The goal is to have base "dra" jobs which just enable
and test those, then "classic-dra" jobs which add DRAControlPlaneController.
This marks the pods with restartable init containers as
`UnschedulableAndUnresolvable` if the feature gate is disabled to avoid
the inconsistency in resource calculation between the scheduler and the
older kubelet.
The feature gate gets locked to "true", with the goal to remove it in two
releases.
All code now can assume that the feature is enabled. Tests for "feature
disabled" are no longer needed and get removed.
Some code wasn't using the new helper functions yet. That gets changed while
touching those lines.
When adding the ephemeral volume feature, the special case for
PersistentVolumeClaim volume sources in kubelet's host path and node
limits checks was overlooked. An ephemeral volume source is another
way of referencing a claim and has to be treated the same way.
Some plugins expect the new feature gate struct. We can inject that additional
parameter via a helper function instead of having to repeat the same anonymous
function for each plugin.
Check the PVC ref count on the node info cache to determine if a pod's
PVCs are in use. If they are and it is using ReadWriteOncePod, fail the
request.
kubernetes#60525 introduced
Balanced attached node volumes feature gate to include volume
count for prioritizing nodes. The reason for introducing this
flag was its usefulness in Red Hat OpenShift Online environment
which is not being used any more. So, removing the flag
as it helps in maintainability of the scheduler code base
as mentioned at kubernetes#101489 (comment)
