Information
Limit the Node and Pod objects that a kubelet could modify.
Rationale:
Using the NodeRestriction plug-in ensures that the kubelet is restricted to the Node and Pod objects that it could modify as defined. Such kubelets will only be allowed to modify their own Node API object, and only modify Pod API objects that are bound to their node.
Solution
Follow the Kubernetes documentation and configure NodeRestriction plug-in on kubelets. Then, edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml on the master node and set the --enable-admission-plugins parameter to a value that includes NodeRestriction.
--enable-admission-plugins=...,NodeRestriction,...
Impact:
None
Default Value:
By default, NodeRestriction is not set.
References:
https://kubernetes.io/docs/admin/kube-apiserver/
https://kubernetes.io/docs/admin/admission-controllers/#noderestriction
https://kubernetes.io/docs/admin/authorization/node/
https://acotten.com/post/kube17-security