- When registering with a 1.17+ API server, a CustomResourceDefinition conversion webhook can now request that only `v1` ConversionReview requests be sent to them. Previously, conversion webhooks were required to support...

### Feature

  // DefaultRequest is the default resource requirement request value by resource name if resource request is omitted.
  // +optional
  map<string, k8s.io.apimachinery.pkg.api.resource.Quantity> defaultRequest = 5;

* Improve handling of custom classes for `Request`s and `APIRoute`s.
    * This helps to more easily solve use cases like:
        * Reading a body before and/or after a request (equivalent to a middleware).
        * Run middleware-like code only for a subset of *path operations*.
        * Process a request before passing it to a *path operation function*. E.g. decompressing, deserializing, etc.

- CRI now supports a "runtime_handler" field for RunPodSandboxRequest, used for selecting the runtime configuration to run the sandbox...

  - *apiserver_storage_list_evaluated_objects_total*: Counter of objects tested in the course of serving a LIST request from etcd, broken down by resource
  - *apiserver_storage_list_returned_objects_total*: Counter of objects returned for a LIST request from etcd, broken down by resource ([#104983](https://github.com/kubernetes/kubernetes/pull/104983), [@MikeSpreitzer](https://github.com/MikeSpreitzer))

- When the kubelet fails to assign CPUs to a Pod because there less available CPUs than the Pod requests, the error message changed from
  `not enough cpus available to satisfy request` to `not enough cpus available to satisfy request: <num_requested> requested, only <num_available> available`. ([#121059](https://github.com/kubernetes/kubernetes/pull/121059), [@matte21](https://github.com/matte21))

    String INDEXER_WEBFS_MAX_DOCUMENT_REQUEST_SIZE = "indexer.webfs.max.document.request.size";

    /** The key of the configuration. e.g. 10000 */
    String INDEXER_DATA_MAX_DOCUMENT_CACHE_SIZE = "indexer.data.max.document.cache.size";

    /** The key of the configuration. e.g. 1048576 */
    String INDEXER_DATA_MAX_DOCUMENT_REQUEST_SIZE = "indexer.data.max.document.request.size";

    /** The key of the configuration. e.g. 100 */

        * At Request audit level or higher, an annotation with key "patch.webhook.admission.k8s.io/round_{round idx}_index_{order idx}" get logged with the JSON payload logging the patch sent by a webhook for given request.

- Kube-apiserver: ensures the namespace of objects sent to admission webhooks matches the request namespace. Previously, objects without a namespace set would have the request namespace populated after mutating admission, and objects with a namespace that did not match the request namespace would be rejected after admission. ([#94637](https://github.com/kubernetes/kubernetes/pull/94637), [@liggitt](https://github.com/liggitt))