### Feature

- Parallelize calls to conversion webhooks when watching from etcd to prevent watchcache from lagging and helps clusters with slow conversion webhooks or transformers. 

  // +optional
  optional string targetContainerName = 2;
}

// EphemeralContainerCommon is a copy of all fields in Container to be inlined in
// EphemeralContainer. This separate type allows easy conversion from EphemeralContainer
// to Container and allows separate documentation for the fields of EphemeralContainer.
// When a new field is added to Container it must be added here as well.
message EphemeralContainerCommon {

- Fewer candidates are enumerated for preemption to improve performance in large clusters. ([#94814](https://github.com/kubernetes/kubernetes/pull/94814), [@adtac](https://github.com/adtac))
- Fix conversions for custom metrics. ([#94481](https://github.com/kubernetes/kubernetes/pull/94481), [@wojtek-t](https://github.com/wojtek-t)) [SIG API Machinery and Instrumentation]

* Add mechanism for Admission Webhooks to specify which version of AdmissionReview they support ([#74998](https://github.com/kubernetes/kubernetes/pull/74998), [@mbohlool](https://github.com/mbohlool))
    * Add mechanism for CRD Conversion Webhooks to specify which version of ConversionReview they support

## Changes by Kind

### Bug or Regression

- Fixes a regression in 1.27.0 that resulted in "missing metadata in converted object" errors when modifying objects for multi-version custom resource definitions with a conversion strategy of `None`. ([#117305](https://github.com/kubernetes/kubernetes/pull/117305), [@ncdc](https://github.com/ncdc)) [SIG API Machinery]

re-enable deprecated legacy behavior of treating the CommonName of X.509 serving certificates as a host name. This behavior has been disabled by default since Kubernetes 1.19 / go 1.15. Serving certificates used by admission webhooks, custom resource conversion webhooks, and aggregated API servers must now include valid Subject Alternative Names. If you are running Kubernetes 1.22 with `GODEBUG=x509ignoreCN=0` set, check the `apiserver_kube_aggregator_x509_missing_san_total` and `apiserver_webhooks_x5...

- Kubernetes 1.24 is built with go1.18, which will no longer validate certificates signed with a SHA-1 hash algorithm by default. See https://golang.org/doc/go1.18#sha1 for more details. If you are using certificates like this in admission or conversion ([#109024](https://github.com/kubernetes/kubernetes/pull/109024), [@stlaz](https://github.com/stlaz))

source code, documentation source, and configuration files. "Object" form shall mean any form resulting from mechanical transformation or translation of a Source form, including but not limited to compiled object code, generated documentation, and conversions to other media types. "Work" shall mean the work of authorship, whether in Source or Object form, made available under the License, as indicated by a copyright notice that is included in or attached to the work (an example is provided in the Appendix...