- Kubeadm: the "kubeadm alpha certs" command is removed now, please use "kubeadm certs" instead. ([#97706](https://github.com/kubernetes/kubernetes/pull/97706), [@knight42](https://github.com/knight42)) [SIG Cluster Lifecycle]

  Also includes percentile groupings. The directory for the default 404 handler includes instructions on how to enable prometheus for monitoring and setting alerts.
  ([#79106](https://github.com/kubernetes/kubernetes/pull/79106), [@vbannai](https://github.com/vbannai))

### Instrumentation

  - The flag `--experimental-control-plane` is now deprecated in favor of  `--control-plane`. The flag `--experimental-upload-certs` is now deprecated in favor of `--upload-certs` ([#78452](https://github.com/kubernetes/kubernetes/pull/78452), [@fabriziopandini](https://github.com/fabriziopandini))

- It is now possible to upload certificates required to join a new control-plane to kubeadm-certs secret using the flag `--experimental-upload-certs` on `init` or upload-certs phase. ([#73907](https://github.com/kubernetes/kubernetes/pull/73907), [@yagonobre](https://github.com/yagonobre))

- Evictions due to pods breaching their ephemeral storage limits are now recorded by the `kubelet_evictions` metric and can be alerted on. ([#87906](https://github.com/kubernetes/kubernetes/pull/87906), [@smarterclayton](https://github.com/smarterclayton)) [SIG Node]

  certificate. ([#120521](https://github.com/kubernetes/kubernetes/pull/120521), [@SataQiu](https://github.com/SataQiu))
- `kubeadm`: removed leftover disclaimer that could be seen in the `kubeadm init phase certs` command help screen, since the "certs" phase of "init" is no longer alpha. ([#121172](https://github.com/kubernetes/kubernetes/pull/121172), [@SataQiu](https://github.com/SataQiu))

- Update Azure load balancer to prevent orphaned public IP addresses ([#82890](https://github.com/kubernetes/kubernetes/pull/82890), [@chewong](https://github.com/chewong))
### Cluster Lifecycle
- Kubeadm alpha certs command now skip missing files ([#85092](https://github.com/kubernetes/kubernetes/pull/85092), [@fabriziopandini](https://github.com/fabriziopandini))

- Kubeadm: graduate the "kubeadm alpha certs" command to a parent command "kubeadm certs". The command "kubeadm alpha certs" is deprecated and will be removed in a future release. Please migrate. ([#94938](https://github.com/kubernetes/kubernetes/pull/94938), [@yagonobre](https://github.com/yagonobre)) [SIG Cluster Lifecycle]

tes/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),...

  - Some kubeadm commands are now allowed to work in a completely offline mode.
- Certificate handling improvements:
  - Renew certs as part of upgrade.
  - New `kubeadm alpha phase certs renew` command for renewing certificates.
  - Certificates created with kubeadm now have improved uniqueness of Distinguished Name fields.
- HA improvements: