- Kubeadm: a new command `kubeadm alpha certs check-expiration` was created in order to help users in managing expiration for local PKI certificates ([#77863](https://github.com/kubernetes/kubernetes/pull/77863),...

* kubeadm: preflight checks on external etcd certificates are now skipped when joining a control-plane node with automatic copy of cluster certificates (--certificate-key) ([#75847](https://github.com/kubernetes/kubernetes/pull/75847), [@fabriziopandini](https://github.com/fabriziopandini))

* The `--bootstrap-kubeconfig` argument to Kubelet previously created the first bootstrap client credentials in the 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...

* [beta] Kubelet certificate rotation through the certificates API has been promoted from alpha to beta. RBAC cluster roles for the certificates controller have been added for common uses of the certificates API, such as the kubelet's.

  - [WARNING: etcd backup strongly recommended](#warning-etcd-backup-strongly-recommended)
  - [Major updates and release themes](#major-updates-and-release-themes)
  - [Action Required](#action-required-1)
    - [Certificates API](#certificates-api)
    - [Cluster Autoscaler](#cluster-autoscaler)
    - [Deployment](#deployment)
    - [Federation](#federation)
    - [Internal Storage Layer](#internal-storage-layer)

- Enforced kubelet to request serving certificates only once it has at least one IP address in the `.status.addresses` of its associated Node object. This avoids requesting DNS-only serving certificates before externally set addresses are in place. Until 1.33, the previous behavior can be opted back into by setting the deprecated `AllowDNSOnlyNodeCSR` feature gate to true...

- Kubeadm: during execution of the "check expiration" command, treat the etcd CA as external if there is a missing etcd CA key file (etcd/ca.key) and perform the proper validation on certificates signed by the etcd CA. Additionally, make sure that the CA for all...

* Fix a race condition in which kubeadm only waits for the kubelets kubeconfig file when it has performed the TLS bootstrap, but wasn't waiting for certificates to be present in the filesystem ([#72030](https://github.com/kubernetes/kubernetes/pull/72030), [@ereslibre](https://github.com/ereslibre))

- Kubeadm: during execution of the "check expiration" command, treat the etcd CA as external if there is a missing etcd CA key file (etcd/ca.key) and perform the proper validation on certificates signed by the etcd CA. Additionally, make sure that the CA for all...

- Kubeadm: during execution of the "check expiration" command, treat the etcd CA as external if there is a missing etcd CA key file (etcd/ca.key) and perform the proper validation on certificates signed by the etcd CA. Additionally, make sure that the CA for all...