2.1.14 Ensure that the RotateKubeletClientCertificate argument is not set to false

Information

Enable kubelet client certificate rotation.

Rationale:

'RotateKubeletClientCertificate' causes the kubelet to rotate its client certificates by creating new CSRs 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 kubelet service file '/etc/systemd/system/kubelet.service.d/10-kubeadm.conf' on each worker node and remove the '--feature-gates=RotateKubeletClientCertificate=false' argument from the 'KUBELET_CERTIFICATE_ARGS' variable.

Based on your system, restart the 'kubelet' service. For example:

systemctl daemon-reload
systemctl restart kubelet.service

Impact:

None

See Also

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

Item Details

Category: IDENTIFICATION AND AUTHENTICATION

References: 800-53|IA-5(1), CSCv6|14.2

Plugin: Unix

Control ID: a58f47e8f5d483de559d8cf6ceff7c9158b8c811eab6f6875f5d3ddda0eee6b5