- Changed behavior of `kube-proxy` by allowing to set `sysctl` values lower than the existing one. ([#120448](https://github.com/kubernetes/kubernetes/pull/120448), [@aroradaman](https://github.com/aroradaman))
- Cleaned up `kube-apiserver` HTTP logs for impersonated requests. ([#119795](https://github.com/kubernetes/kubernetes/pull/119795), [@sttts](https://github.com/sttts))

* Move shell completion generation into 'kubectl completion' command ([#23801](https://github.com/kubernetes/kubernetes/pull/23801), [@sttts](https://github.com/sttts))
* Fix strategic merge diff list diff bug ([#26418](https://github.com/kubernetes/kubernetes/pull/26418), [@AdoHe](https://github.com/AdoHe))

* Fixed API server panic during concurrent GET or LIST requests with non-empty `resourceVersion`. ([#65092](https://github.com/kubernetes/kubernetes/pull/65092), [@sttts](https://github.com/sttts))
* Fix issue that vSphere cloud provider cannot delete volume which is provisioned in datastore specified in storageclass ([#65550](https://github.com/kubernetes/kubernetes/pull/65550), [@w-leads](https://github.com/w-leads))

* SELinux Overhaul ([#33663](https://github.com/kubernetes/kubernetes/pull/33663), [@pmorie](https://github.com/pmorie))
* Add SNI support to the apiserver ([#35109](https://github.com/kubernetes/kubernetes/pull/35109), [@sttts](https://github.com/sttts))

* Return apiserver panics as 500 errors instead terminating the apiserver process. ([#68001](https://github.com/kubernetes/kubernetes/pull/68001), [@sttts](https://github.com/sttts))

* Make clear that meta.KindToResource is only a guess ([#45272](https://github.com/kubernetes/kubernetes/pull/45272), [@sttts](https://github.com/sttts))

* Add APIService conditions ([#43301](https://github.com/kubernetes/kubernetes/pull/43301), [@deads2k](https://github.com/deads2k))

- Fixed code-generator client-gen to work with `api/v1`-like package structure. ([#125162](https://github.com/kubernetes/kubernetes/pull/125162), [@sttts](https://github.com/sttts)) [SIG API Machinery and Apps]

- Fix kube-apiserver startup to wait for APIServices to be installed into the HTTP handler before reporting readiness. ([#89147](https://github.com/kubernetes/kubernetes/pull/89147), [@sttts](https://github.com/sttts)) [SIG API Machinery]
- Fix kubectl create --dryrun client ignores namespace ([#90502](https://github.com/kubernetes/kubernetes/pull/90502), [@zhouya0](https://github.com/zhouya0))

## Release Notes From SIGs

### SIG API Machinery

- Added unit test helpers to validate CEL and patterns in CustomResourceDefinitions. ([#129028](https://github.com/kubernetes/kubernetes/pull/129028), [@sttts](https://github.com/sttts))
- Added validation of `containerLogMaxFiles` within kubelet configuration files. ([#129072](https://github.com/kubernetes/kubernetes/pull/129072), [@kannon92](https://github.com/kannon92))