pull/57902), [@kawych](https://github.com/kawych))

* On cluster provision or upgrade, kubeadm now generates certs and secures all connections to the etcd static-pod with mTLS. This includes the etcd serving cert, the etcd peer cert, and the apiserver etcd client cert. Flags and hostMounts are added to the etcd and apiserver static-pods to load these certs. For connections to etcd, https is now used in favor of http. ([#57415](https://github.com/kubernetes/kubernetes/pull/57415), [@s...

### Documentation

- `kubectl debug` will now print a warning message when using the `--target` option since many container runtimes do not support this yet. ([#101074](https://github.com/kubernetes/kubernetes/pull/101074), [@verb](https://github.com/verb)) [SIG CLI]

### Bug or Regression

    * Fixed the webhook admission plugin so that webhook author could use the DNS name of the service as the CommonName when generating the server cert for the webhook.
    * Action required:

- `kubectl debug` gains support for changing container images when copying a pod for debugging, similar to how `kubectl set image` works. See `kubectl help debug` for more information. ([#96058](https://github.com/kubernetes/kubernetes/pull/96058), [@verb](https://github.com/verb)) [SIG CLI]

### Documentation

- The underlying format of the `CPUManager` state file has changed. Upgrades should be seamless, but any third-party tools that rely on reading the previous format need to be updated. ([#84462](https://github.com/kub...

    - [SIG VMWare](#sig-vmware-1)
    - [SIG Windows](#sig-windows-1)
  - [Other Notable Changes](#other-notable-changes-11)
    - [Bug Fixes](#bug-fixes)
    - [Not Very Notable (that is, non-user-facing)](#not-very-notable-that-is-non-user-facing)
  - [External Dependencies](#external-dependencies)
- [v1.12.0-rc.2](#v1120-rc2)
  - [Downloads for v1.12.0-rc.2](#downloads-for-v1120-rc2)

* genericapiserver: cut off certificates api dependency ([#39947](https://github.com/kubernetes/kubernetes/pull/39947), [@sttts](https://github.com/sttts))
* genericapiserver: extract CA cert from server cert and SNI cert chains ([#39022](https://github.com/kubernetes/kubernetes/pull/39022), [@sttts](https://github.com/sttts))

    * Fixed the webhook admission plugin so that webhook author could use the DNS name of the service as the CommonName when generating the server cert for the webhook.
    * Action required:

certificates directory as `kubelet-client.key` and `kubelet-client.crt`.  Subsequent certificates created by cert rotation were created in a combined PEM file that was atomically rotated as `kubelet-client-DATE.pem` in that directory, which meant clients relying on the `node.kubeconfig` generated by bootstrapping would never use a rotated cert.  The initial bootstrap certificate is now generated into the cert directory as a PEM file and symlinked to `kubelet-client-current.pem` so that the generated kubeconfig...

  you want to set the equivalent of any of the `--iptables-xxx` options.)
  
  As this code is still very new, it has not been heavily optimized yet;
  while it is expected to _eventually_ have better performance than the
  iptables backend, very little performance testing has been done so far. ([#121046](https://github.com/kubernetes/kubernetes/pull/121046), [@danwinship](https://github.com/danwinship))