The kubelet server certificate rotation should be enabled

kubernetes

Set up the kubernetes integration.

Description

Kubelet server certificate rotation should be enabled. RotateKubeletServerCertificate causes the kubelet to both request a serving certificate after bootstrapping its client credentials and rotate the certificate as its existing credentials expire. This automated periodic rotation ensures that the there are no downtimes due to expired certificates and thus addressing availability in the CIA security triad.

Note: This recommendation only applies if you let kubelets get their certificates from the API server. If your kubelet certificates come from an outside authority/tool (e.g. Vault), you need to handle the rotation manually.

Remediation

  1. On the master node, edit /var/lib/kubelet/kubeadm-flags.env and set the parameter KUBELET_CERTIFICATE_ARGS to include --feature-gates=RotateKubeletServerCertificate=true or as an alternative, and suggested as a last resort, edit the kubelet service file /etc/systemd/system/kubelet.service.d/10-kubeadm.conf on each worker node and set the below parameter in KUBELET_CERTIFICATE_ARGS variable:
--feature-gates=RotateKubeletServerCertificate=true
  1. Restart the kubelet service.