The generated ResourceClaim name and the names of the ResourceClaimTemplate and
ResourceClaim referenced by a pod must be valid according to the resource API,
otherwise the pod cannot start.
Checking this was removed from the original implementation out of concerns
about validating fields in core against limitations imposed by a separate,
alpha API. But as this was pointed out again in
https://github.com/kubernetes/kubernetes/pull/116254#discussion_r1134010324
it gets added back.
The same strings that worked before still work now. In particular, the
constraints for a spec.resourceClaim.name are still the same (DNS label).
The name "PodScheduling" was unusual because in contrast to most other names,
it was impossible to put an article in front of it. Now PodSchedulingContext is
used instead.
This fixes the following warning (error?) in the apiserver:
E0126 18:10:38.665239 16370 fieldmanager.go:210] "[SHOULD NOT HAPPEN] failed to update managedFields" err="failed to convert new object (test/claim-84; resource.k8s.io/v1alpha1, Kind=ResourceClaim) to smd typed: .status.reservedFor: element 0: associative list without keys has an element that's a map type" VersionKind="/, Kind=" namespace="test" name="claim-84"
The root cause is the same as in e50e8a0c91:
nothing in Kubernetes outright complains about a list of items where the item
type is comparable in Go, but not a simple type. This nonetheless isn't
supposed to be done in the API and can causes problems elsewhere.
For the ReservedFor field, everything seems to work okay except for the
warning. However, it's better to follow conventions and use a map. This is
possible in this case because UID is guaranteed to be a unique key.
Validation is now stricter than before, which is a good thing: previously,
two entries with the same UID were allowed as long as some other field was
different, which wasn't a situation that should have been allowed.
This is in response to review feedback. Checking for valid node names and the
set property catches programming mistakes in the components that have write
permission.
This adds a new resource.k8s.io API group with v1alpha1 as version. It contains
four new types: resource.ResourceClaim, resource.ResourceClass, resource.ResourceClaimTemplate, and
resource.PodScheduling.
