* Increase timeout for federated ingress test. ([#33610](https://github.com/kubernetes/kubernetes/pull/33610), [@quinton-hoole](https://github.com/quinton-hoole))
* Remove headers that are unnecessary for proxy target ([#34076](https://github.com/kubernetes/kubernetes/pull/34076), [@mbohlool](https://github.com/mbohlool))

- Fixed an issue where kubelet does not set case-insensitive headers for http probes. (#117182, @dddddai) ([#117333](https://github.com/kubernetes/kubernetes/pull/117333), [@dddddai](https://github.com/dddddai)) [SIG API Machinery, Apps and Node]

### Feature

- 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 ([#120359](https://github.com/kubernetes/kubernetes/pull/120359), [@Jefftree](https://github.com/Jefftree)) [SIG API Machinery]

- 'Container `preStop` and `postStart` lifecycle handlers using `httpGet` now
  honor the specified `scheme` and `headers` fields. This enables setting custom
  headers and changing the scheme to `HTTPS`, consistent with container
  startup/readiness/liveness probe capabilities. Lifecycle handlers configured

- 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]

- The `NodeConfiguration` kind in the kubeadm v1alpha2 API has been renamed `JoinConfiguration` in v1alpha3...

- Fixed an issue where kubelet does not set case-insensitive headers for http probes. (#117182, @dddddai) ([#117331](https://github.com/kubernetes/kubernetes/pull/117331), [@dddddai](https://github.com/dddddai)) [SIG API Machinery, Apps and Node]

"statusCode","requestHeaders","requestHeadersNames","strAbort","getResponseHeader","getAllResponseHeaders","setRequestHeader","overrideMimeType","mimeType","status","abort","statusText","finalText","crossDomain","host","hasContent","ifModified","headers","beforeSend","success","send","nativeStatusText","responses","isSuccess","response","modified","ct","finalDataType","firstDataType","ajaxHandleResponses","conv2","current","conv","dataFilter","throws","ajaxConvert","getJSON","getScript","text sc...

* Scheduler metrics are now marked as with the ALPHA stability level. ([#81576](https://github.com/kubernetes/kubernetes/pull/81576), [@logicalhan](https://github.com/logicalhan))
* cache-control headers are now set appropriately.  Only openapi is cacheable if etags match. ([#81946](https://github.com/kubernetes/kubernetes/pull/81946), [@deads2k](https://github.com/deads2k))

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