* Fix issue where on re-registration...

- kubeadm: removed the deprecated sub-phase of 'init kubelet-finilize' called `experimental-cert-rotation`, and use 'enable-client-cert-rotation' instead. ([#126913](https://github.com/kubernetes/kubernetes/pull/126913), [@pacoxu](https://github.com/pacoxu)) [SIG Cluster Lifecycle]

`system:masters` Group, which was undesired. Executing `kubeadm init phase kubeconfig all` or just `kubeadm init` will now generate the new `super-admin.conf` file. The cluster admin can then decide to keep the file present on a node host or move it to a safe location. `kubadm certs renew` will renew the certificate in `super-admin.conf` to one year if the file exists; if it does not exist a "MISSING" note will be printed. `kubeadm upgrade apply` for this release will migrate this particular node to the two file...

- Structured Authentication Configuration now supports `DiscoveryURL`. If specified, `discoveryURL` overrides the URL used to fetch discovery information. This is for scenarios where the well-known and jwks endpoints are hosted at a different location than the issuer (such as locally in the cluster).
   ([#123527](https://github.com/kubernetes/kubernetes/pull/123527), [@aramase](https://github.com/aramase))

### GCP

- Fixed liveness probe in fluentd-gcp cluster addon ([#74522](https://github.com/kubernetes/kubernetes/pull/74522), [@Pluies](https://github.com/Pluies))
- Reduced GCE log rotation check from 1 hour to every 5 minutes.  Rotation policy is unchanged (new day starts, log file size > 100MB). ([#72062](https://github.com/kubernetes/kubernetes/pull/72062), [@jpbetz](https://github.com/jpbetz))

### Network

- Kubectl cluster-info dump changed to only display a message telling you the location where the output was written when the output is not standard output. ([#88765](https://github.com/kubernetes/kubernetes/pull/88765), [@brianpursley](https://github.com/brianpursley)) [SIG CLI]

- kube-controller-manager and cloud-controller-manager now hold generated serving certificates in-memory unless a writeable location is specified with --cert-dir ([#69884](https://github.com/kubernetes/kubernetes/pull/69884), [@liggitt](https://github.com/liggitt))

* Kubelets using TLS bootstrapping (`--bootstrap-kubeconfig`) or certificate rotation (`--rotate-certificates`) store certificates in the directory specified by `--cert-dir`. The default location (`/var/run/kubernetes`) is automatically erased on reboot on some platforms, which can prevent the kubelet from authenticating to the API server after a reboot. Specifying a non-transient location, such as `--cert-dir=/var/lib/kubelet/pki`, is recommended.

* When using client or server certificate rotation, the Kubelet will no longer wait until the initial rotation succeeds or fails before starting static pods.  This makes running self-hosted masters with rotation more predictable. ([#58930](https://github.com/kubernetes/kubernetes/pull/58930), [@smarterclayton](https://github.com/smarterclayton))

- Kubeadm: Removed support for mounting /etc/pki as an additional Linux system CA location
  in kube-apisever and kube-controller-manager pods. Instead, it shifted to supporting the
  mounting of /etc/pki/ca-trust and /etc/pki/tls/certs. The locations /etc/ca-certificate,
  /usr/share/ca-certificates, /usr/local/share/ca-certificates, and /etc/ssl/certs continued