- Fixed a regression in default 1.27 configurations in kube-apiserver: fixed the AggregatedDiscoveryEndpoint feature (beta in 1.27+) to successfully fetch discovery information from aggregated API servers that do not check `Accept` headers when serving the `/apis` endpoint ([#120360](https://github.com/kubernetes/kubernetes/pull/120360), [@Jefftree](https://github.com/Jefftree)) [SIG API Machinery]

</p>

<pre>
type T1[P T1[P]] …                    // illegal: T1 refers to itself
type T2[P interface{ T2[int] }] …     // illegal: T2 refers to itself
type T3[P interface{ m(T3[int])}] …   // illegal: T3 refers to itself
type T4[P T5[P]] …                    // illegal: T4 refers to T5 and
type T5[P T4[P]] …                    //          T5 refers to T4

- kube-apiserver: a new `--requestheader-uid-headers` flag allows configuring request header authentication to obtain the authenticating user's UID from the specified headers. The suggested value for the new option is `X-Remote-Uid`. When specified, the `kube-system/extension-apiserver-authentication` configmap will include the value in its `.data[requestheader-uid-headers]` field. ([#115834](https://github.com/kubernetes/kubernetes/pull/115834), [@stlaz](...

*   It is now possible to set multiple manifest URL headers with the kubelet's `--manifest-url-header` flag. Multiple headers for the same key will be added in the order provided. The ManifestURLHeader field in KubeletConfiguration object (kubeletconfig/v1alpha1) is now a map[string][]string, which facilitates writing JSON and YAML files....

    </magic>
  </mime-type>
  <mime-type type="application/x-axcrypt">
    <_comment>AxCrypt</_comment>
    <glob pattern="*.axx" />
    <magic priority="60">
      <!-- AxCrypt block header, skip length field, then Header of type Preamble -->
      <match value="0xc0b9072e4f93f146a015792ca1d9e821" type="string" offset="0">
         <match value="2" type="big32" offset="17" />
      </match>
    </magic>
  </mime-type>

### Other notable changes

pkg html/template, func ParseFS(fs.FS, ...string) (*Template, error)
pkg html/template, method (*Template) ParseFS(fs.FS, ...string) (*Template, error)
pkg io, func NopCloser(Reader) ReadCloser
pkg io, func ReadAll(Reader) ([]uint8, error)
pkg io, type ReadSeekCloser interface { Close, Read, Seek }
pkg io, type ReadSeekCloser interface, Close() error
pkg io, type ReadSeekCloser interface, Read([]uint8) (int, error)

### Other (Cleanup or Flake)

- Kube-apiserver: sets an upper-bound on the lifetime of idle keep-alive connections and time to read the headers of incoming requests ([#103958](https://github.com/kubernetes/kubernetes/pull/103958), [@liggitt](https://github.com/liggitt)) [SIG API Machinery and Node]

## Dependencies

### Added

- Leader Migration for controller managers graduated to beta. ([#103533](https://github.com/kubernetes/kubernetes/pull/103533), [@jiahuif](https://github.com/jiahuif)) [SIG API Machinery and Cloud Provider]

- Kube-apiserver: multiple comma-separated protocols in a single X-Stream-Protocol-Version header are now recognized, in addition to multiple headers, complying with RFC2616 ([#89857](https://github.com/kubernetes/kubernetes/pull/89857), [@tedyu](https://github.com/tedyu)) [SIG API Machinery]