remove enum markers on types without validation

[jiahuif]

What type of PR is this?

/kind bug
/kind feature

What this PR does / why we need it:

This PR unmarks a few types that are not validated to be in a set of defined values as enum type. In production, we see applications and/or cloud providers setting these fields to be a value that is not built in.

Which issue(s) this PR fixes:

xref: kubernetes-client/python#1733
xref: kubernetes-client/python#1735
xref: kubernetes-client/python#1739

Special notes for your reviewer:

Release note: this affects only generated clients but not directly the end users.

Does this PR introduce a user-facing change?

Fixes a 1.23 regression in published openAPI that incorrectly identified some fields as enum values

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

[k8s-triage-robot]

This PR may require API review.

If so, when the changes are ready, complete the pre-review checklist and request an API review.

Status of requested reviews is tracked in the API Review project.

[apelisse]

Looks good, but can we clarify the doc on these fields so that we have a better understanding why/how that happened?
Their docs don't read like other values should be accepted. @thockin

[jiahuif]

NodeConditionType is left as a TODO as in the comment. We observed cloud providers filling status of load balancers, node agents to this field.

// These are valid conditions of node. Currently, we don't have enough information to decide
// node condition. In the future, we will add more. The proposed set of conditions are:
// NodeReachable, NodeLive, NodeReady, NodeSchedulable, NodeRunnable.

https://github.com/kubernetes/kubernetes/blob/v1.24.0-alpha.3/staging/src/k8s.io/api/core/v1/types.go#L5053-L5069

PodConditionType is defined to be unbounded, ref: https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle/#pod-readiness-gate

[apelisse]

// These are valid conditions of node. Currently, we don't have enough information to decide
// node condition. In the future, we will add more. The proposed set of conditions are:
// NodeReachable, NodeLive, NodeReady, NodeSchedulable, NodeRunnable.

That first comment is hand-wavy, but not as in "we can have other values", but rather as "This was written when Kubernetes started and we didn't really know where we're going". I'm sure we can improve this.

PodConditionType is defined to be unbounded, ref: https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle/#pod-readiness-gate

I'm sure we can improve this field comment.

[apelisse]

Thanks,
/lgtm
/approve

[jiahuif]

I've manually checked the validation of every type listed above and updated as needed.

[jiahuif]

/retest

[liggitt]

/hold cancel
/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: apelisse, jiahuif, liggitt

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Needs approval from an approver in each of these files:

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• pkg/generated/openapi/OWNERS [liggitt]
• staging/src/k8s.io/api/OWNERS [liggitt]

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[apelisse]

Awesome, let's cherry-pick this in the the latest release!

[leilajal]

/triage accepted

[sftim]

We now have a gap where these non-exhaustive, enum-like field values are not documented. Folks will previously have found those explanations useful.

See kubernetes/website#32833 (review) for an example where the v1.23 docs enumerate taints and list meanings (NoExecute, NoSchedule and PreferNoSchedule) but the v1.24 docs won't.

I'll file a feature request about this.

[liggitt]

The enums were removed from the 1.23 static file as well in #109179

[sftim]

That's OK by accident because SIG Docs makes an assumption that once we've made a minor release the [Open]API for that release doesn't change.