- Migrated validation in `resource.k8s.io` to declarative validation.
  When the `DeclarativeValidation` feature gate is enabled, mismatches with existing validation are reported via metrics.

Kubelet to establish connections to Pods, retrieve container logs, and more. While Kubernetes already validates the proxying address for Nodes, a bug in kube-apiserver made it possible to bypass this validation. Bypassing this validation could allow authenticated requests destined for Nodes to be redirected to the API Server through its private network.

The merged fix enforces validation against the proxying address for a Node. In some cases, the fix can break clients that depend on the...

  - warn - perform server-side validation and warn on any invalid fields (but ultimately let the request succeed by dropping any invalid fields from the object). If validation is not available on the server, perform no validation.

- Vendor: updated system-validators to v1.9.0. ([#128149](https://github.com/kubernetes/kubernetes/pull/128149), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle and Node]
- Vendor: updated system-validators to v1.9.1. ([#128533](https://github.com/kubernetes/kubernetes/pull/128533), [@neolit123](https://github.com/neolit123))

- The validation of `replicas` field in the ReplicationController `/scale` subresource has been migrated to declarative validation.
  If the `DeclarativeValidation` feature gate is enabled, mismatches with existing validation are reported via metrics.

- The minimum value validation of ReplicationController's `replicas` and `minReadySeconds` fields have been migrated to declarative validation. The requiredness of both fields is also declaratively validated.
  If the `DeclarativeValidation` feature gate is enabled, mismatches with existing validation are reported via metrics.

- Fixed EndpointSlice port name validation to match Endpoint port name validation (allowing port names longer than 15 characters) ([#84481](https://github.com/kubernetes/kubernetes/pull/84481), [@robscott](https://github.com/robscott))

- `StatefulSet` names must be DNS labels, rather than subdomains. Any `StatefulSet`
  which took advantage of subdomain validation (by having dots in the name) can't
  possibly have worked, because we eventually set `pod.spec.hostname` from the `StatefulSetName`,
  and that is validated as a DNS label. ([#114172](https://github.com/kubernetes/kubernetes/pull/114172), [@thockin](https://github.com/thockin))

that workloads (e.g. Deployments, DaemonSets, etc.) which used `PersistentDisk` volumes were using them in read-only mode.  This validation provided very little value at relatively host implementation cost, and will no longer be validated.  If this is a problem for a specific use-case, please set the `SkipReadOnlyValidationGCE` gate to false to re-enable the validation, and file a Kubernetes bug with details. ([#121083](https://github.com/kubernetes/kubernetes/pull/121083), [@thockin](https://github.com/thockin))...

Service Level Indicators (SLIs) and Service Level Objectives (SLOs) for the system.
Here's the release [scalability validation report].

[SIG Scalability]: https://github.com/kubernetes/community/tree/master/sig-scalability
[scalability validation report]: https://github.com/kubernetes/sig-release/blob/master/releases/release-1.8/scalability_validation_report.md

### SIG Scheduling