Information
Disable the read-only port.
Rationale:
The Kubelet process provides a read-only API in addition to the main Kubelet API. Unauthenticated access is provided to this read-only API which could possibly retrieve potentially sensitive information about the cluster.
Impact:
Removal of the read-only port will require that any service which made use of it will need to be re-configured to use the main Kubelet API.
Solution
If using a Kubelet config file, edit the file to set readOnlyPort to 0.
If using command line arguments, edit the kubelet service file /etc/kubernetes/kubelet.conf on each worker node and set the below parameter in KUBELET_SYSTEM_PODS_ARGS variable.
--read-only-port=0
Based on your system, restart the kubelet service. For example:
systemctl daemon-reload
systemctl restart kubelet.service
Default Value:
By default, --read-only-port is set to 10255/TCP. However, if a config file is specified by --config the default value for readOnlyPort is 0.