- X.509 client certificate authentication to the kube-apiserver now produces credential IDs (derived from the certificate's signature) , for use in audit logging. ([#125634](https://github.com/kubernetes/kubernetes/pull/125634), [@ahmedtd](https://github.com/ahmedtd)) [SIG API Machinery, Auth and Testing]

* Add /bin/tee symlink to bazel build for busybox, so that CI builds have /bin/tee ([#55417](https://github.com/kubernetes/kubernetes/pull/55417), [@justinsb](https://github.com/justinsb))
* Reduce log noise produced by prometheus-to-sd, by bumping it to version 0.2.2. ([#54635](https://github.com/kubernetes/kubernetes/pull/54635), [@loburm](https://github.com/loburm))

- The `gcp` and `azure` auth plugins have been removed from client-go and kubectl. See https://github.com/Azure/kubelogin and https://cloud.google.com/blog/products/containers-kubernetes/kubectl-auth-changes-in-gke ([#110013](https://github.com/kubernetes/kubernetes/pull/110013), [@enj](https://github.com/enj))

- The `gcp` and `azure` auth plugins have been removed from `client-go` and `kubectl`. See [kubelogin](https://github.com/Azure/kubelogin) and [Kubectl Auth Changes in GKE](https://cloud.google.com/blog/products/containers-kubernetes/kubectl-auth-changes-in-gke) for details about the cloud-specific replacements. ([#112341](https://github.com/kubernetes/kubernetes/pull/112341), [@enj](https://github.com/enj))

### API Change

* Transition service account controller clients to TokenRequest API ([#72179](https://github.com/kubernetes/kubernetes/pull/72179), [@WanLinghao](https://github.com/WanLinghao))
* kubeadm: reimplemented IPVS Proxy check that produced confusing warning message. ([#75036](https://github.com/kubernetes/kubernetes/pull/75036), [@bart0sh](https://github.com/bart0sh))

## Changelog since v1.19.0

## What's New (Major Themes)

### Dockershim deprecation

Docker as an underlying runtime is being deprecated. Docker-produced images will continue to work in your cluster with all runtimes, as they always have.