1.3.7 Ensure that the RotateKubeletServerCertificate argument is set to true

Information

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.

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

Impact:

None

See Also

https://workbench.cisecurity.org/files/1788

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-3(6), CSCv6|14.2

Plugin: Unix

Control ID: 30a6f36b10f0e305939f13aadf8031580e3a3fc348e86cc4b949f8271b2b0c16