- 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](...

- Added new k8s.io/component-helpers repository providing shared helper code for (core) components. ([#92507](https://github.com/kubernetes/kubernetes/pull/92507), [@ingvagabund](https://github.com/ingvagabund)) [SIG Apps, Node, Release and Scheduling]

- Added e2e tests for volume group snapshots. ([#128972](https://github.com/kubernetes/kubernetes/pull/128972), [@manishym](https://github.com/manishym)) [SIG Cloud Provider, Storage and Testing]
- Added unit test helpers to validate CEL and patterns in CustomResourceDefinitions. ([#129028](https://github.com/kubernetes/kubernetes/pull/129028), [@sttts](https://github.com/sttts))

* Fix init container status reporting when active deadline is exceeded. ([#46305](https://github.com/kubernetes/kubernetes/pull/46305), [@sjenning](https://github.com/sjenning))

* Moved qos to api.helpers. ([#44906](https://github.com/kubernetes/kubernetes/pull/44906), [@k82cn](https://github.com/k82cn))

* `kubectl auth reconcile` only works with rbac.v1; all the core helpers have been switched over to use the external types. ([#63967](https://github.com/kubernetes/kubernetes/pull/63967), [@deads2k](https://github.com/deads2k))

* fix kubelet event recording for selected events. ([#46246](https://github.com/kubernetes/kubernetes/pull/46246), [@derekwaynecarr](https://github.com/derekwaynecarr))
* Moved qos to api.helpers. ([#44906](https://github.com/kubernetes/kubernetes/pull/44906), [@k82cn](https://github.com/k82cn))

- Replaced Boolean-pointer-helper functions with the `k8s.io/utils/ptr` implementations. ([#132794](https://github.com/kubernetes/kubernetes/pull/132794), [@PatrickLaabs](https://github.com/PatrickLaabs)) [SIG API Machinery, Auth, CLI, Node and Testing]

- Made `kubectl-convert` binary linking static (also affects the deb and rpm packages). ([#114228](https://github.com/kubernetes/kubernetes/pull/114228), [@saschagrunert](https://github.com/saschagrunert))
- Migrated controller helper functions to use contextual logging. ([#115049](https://github.com/kubernetes/kubernetes/pull/115049), [@fatsheep9146](https://github.com/fatsheep9146))

- Added `kubectl node drain` helper callbacks `OnPodDeletionOrEvictionStarted`
  and `OnPodDeletionOrEvictionFailed`; people extending `kubectl` can use these
  new callbacks for more granularity. Deprecated the `OnPodDeletedOrEvicted`

*   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....