Details
Enable kubelet server certificate rotation on controller-manager.
Rationale:
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. In case your kubelet certificates come from an outside authority/tool (e.g. Vault) then you need to take care of rotation yourself.
Impact:
None
Solution
Edit the Controller Manager pod specification file /etc/kubernetes/manifests/kube-controller-manager.yaml on the master node and set the –feature-gates parameter to include RotateKubeletServerCertificate=true.
–feature-gates=RotateKubeletServerCertificate=true
Default Value:
By default, RotateKubeletServerCertificate is set to ‘true’ this recommendation verifies that it has not been disabled.
Supportive Information
The following resource is also helpful.
This security hardening control applies to the following category of controls within NIST 800-53: System and Communications Protection.This control applies to the following type of system Unix.