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 setup. Subsequent kubeadm releases will continue to optionally renew the certificate in `super-admin.conf` if the file exists on disk and if renew on upgrade is not disabled. `kubeadm join --control-plane` will...

- `kubeadm alpha certs renew --csr-only` now reads the current certificates as the authoritative source for certificates attributes (same as kubeadm alpha certs renew). ([#77780](https://github.com/kubernetes/kubernetes/pull/77780), [@fabriziopandini](https://github.com/fabriziopandini))

- Added option to create CSRs instead of certificates for kubeadm init phase certs and kubeadm alpha certs renew ([#70809](https://github.com/kubernetes/kubernetes/pull/70809), [@liztio](https://github.com/liztio))

- Remove the deprecated flags `--csr-only` and `--csr-dir` from `kubeadm certs renew`. Please use `kubeadm certs generate-csr` instead. ([#104796](https://github.com/kubernetes/kubernetes/pull/104796), [@RA489](https://github.com/RA489))

- The commands `kubeadm certs renew` and `kubeadm certs check-expiration` now honor the `cert-dir` flag on a running Kubernetes cluster. ([#110709](https://github.com/kubernetes/kubernetes/pull/110709), [@chendave](https://github.com/chendave))

- Kubeadm: remove the deprecated `--csr-only` and `--csr-dir` flags from `kubeadm init phase certs`. Deprecate the same flags under `kubeadm certs renew`. In both the cases the command `kubeadm certs generate-csr` should be used instead. ([#102108](https://github.com/kubernetes/kubernetes/pull/102108), [@neolit123](https://github.com/neolit123))

* kubeadm allows the kubelets in the cluster to automatically renew their client certificates ([#53252](https://github.com/kubernetes/kubernetes/pull/53252), [@kad](https://github.com/kad))