- Kubeadm: allow the "certs check-expiration" command to not require the existence of the cluster CA key (ca.key file) when checking the expiration of managed certificates in kubeconfig files. ([#106929](https://github.com/kubernetes/kubernetes/pull/106929), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

- Kubeadm: allow the `certs check-expiration` command to not require the existence of the cluster CA key (ca.key file) when checking the expiration of managed certificates in kubeconfig files. ([#106854](https://github.com/kubernetes/kubernetes/pull/106854), [@neolit123](https://github.com/neolit123))

### Bug or Regression

- Kubeadm: allow the "certs check-expiration" command to not require the existence of the cluster CA key (ca.key file) when checking the expiration of managed certificates in kubeconfig files. ([#106931](https://github.com/kubernetes/kubernetes/pull/106931), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

    * request a client certificate from the API server during the boot cycle and pause
    * waiting for the request to be satisfied. It will continually refresh the certificate
    * as the certificates expiration approaches.

- Kubeadm: allow the "certs check-expiration" command to not require the existence of the cluster CA key (ca.key file) when checking the expiration of managed certificates in kubeconfig files. ([#106930](https://github.com/kubernetes/kubernetes/pull/106930), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

- 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))

  // identifier of the apiserver.
  // +optional
  optional string audience = 1;

  // expirationSeconds is the requested duration of validity of the service
  // account token. As the token approaches expiration, the kubelet volume
  // plugin will proactively rotate the service account token. The kubelet will
  // start trying to rotate the token if the token is older than 80 percent of

- Kubeadm: fix panic in the command "kubeadm certs check-expiration" when "/etc/kubernetes/pki" exists but cannot be read. ([#124124](https://github.com/kubernetes/kubernetes/pull/124124), [@carlory](https://github.com/carlory)) [SIG Cluster Lifecycle]

- Kubeadm: fix panic in the command "kubeadm certs check-expiration" when "/etc/kubernetes/pki" exists but cannot be read. ([#124124](https://github.com/kubernetes/kubernetes/pull/124124), [@carlory](https://github.com/carlory)) [SIG Cluster Lifecycle]

- Kubeadm: fix panic in the command "kubeadm certs check-expiration" when "/etc/kubernetes/pki" exists but cannot be read. ([#124124](https://github.com/kubernetes/kubernetes/pull/124124), [@carlory](https://github.com/carlory)) [SIG Cluster Lifecycle]