// +optional
  optional bool optional = 2;
}

// Selects a key from a ConfigMap.
// +structType=atomic
message ConfigMapKeySelector {
  // The ConfigMap to select from.
  optional LocalObjectReference localObjectReference = 1;

  // The key to select.
  optional string key = 2;

  // Specify whether the ConfigMap or its key must be defined
  // +optional
  optional bool optional = 3;
}

- The PodDisruptionBudget API has been promoted to policy/v1 with no schema changes. The only functional change is that an empty selector (`{}`) written to a policy/v1 PodDisruptionBudget now selects all pods in the namespace. The behavior of the policy/v1beta1 API remains unchanged. The policy/v1beta1 PodDisruptionBudget API is deprecated and will no longer be served in 1.25+. ([#99290](https://github.com/kubernetes/kubernetes/pull/99290), [...

	    statement</a>.</li>
	</ul>
</li>

<li>
	A <a href="#Select_statements">"select" statement</a> in which:
	<ul>
	<li>there are no "break" statements referring to the "select" statement, and</li>
	<li>the statement lists in each case, including the default if present,
	    end in a terminating statement.</li>
	</ul>
</li>

<li>

* kubectl port-forward now allows using resource name (e.g., deployment/www) to select a matching pod, as well as the use of --pod-running-timeout to wait until at least one pod is running. ([#59705](https://github.com/kubernetes/kubernetes/pull/59705), [@phsiao](https://github.com/phsiao))

* rbd: default image format to v2 instead of deprecated v1 ([#51574](https://github.com/kubernetes/kubernetes/pull/51574), [@dillaman](https://github.com/dillaman))
* Surface reasonable error when client detects connection closed. ([#51381](https://github.com/kubernetes/kubernetes/pull/51381), [@mengqiy](https://github.com/mengqiy))

### API Change

- A fix in the `resource.k8s.io/v1alpha1/ResourceClaim` API avoids harmless (?) ".status.reservedFor: element 0: associative list without keys has an element that's a map type" errors in the apiserver. Validation now rejects the incorrect reuse of the same UID in different entries. ([#115354](https://github.com/kubernetes/kubernetes/pull/115354), [@pohly](https://github.com/pohly))

- Fix a bug that when PodTopologySpread rejects Pods, they may be stuck in Pending state for 5 min in a worst case scenario.
  The same problem could happen with custom plugins which have Pod/Add or Pod/Update in EventsToRegister,

- The RuntimeClass scheduler can now simplify steering Linux or Windows pods to appropriate nodes
- All Windows nodes now get the new label `node.kubernetes.io/windows-build` that reflects the Windows major, minor, and build number that are needed to match compatibility between Windows containers and Windows worker nodes.


## Deprecations and Removals

- The API server now detects and fails on startup if there are conflicting issuers between JWT authenticators and service account configurations. Previously, such configurations would run but could be inconsistently effective depending on the credential. ([#123561](https://g...

### Bug or Regression