Enable the NodeRestriction Admission Control Plugin
An XCCDF Rule
Description
To limit the Node and Pod objects that a kubelet could modify,
ensure that the NodeRestriction plugin on kubelets is enabled in
the api-server configuration by running the following command:
$ oc -n openshift-kube-apiserver get configmap config -o json | jq -r '.data."config.yaml"' | jq '.apiServerArguments."enable-admission-plugins"'
warning alert: Warning
This rule's check operates on the cluster configuration dump.
Therefore, you need to use a tool that can query the OCP API, retrieve the following:
-
{{if ne .hypershift_cluster "None"}}/api/v1/namespaces/{{.hypershift_namespace_prefix}}-{{.hypershift_cluster}}/configmaps/kas-config{{else}}/api/v1/namespaces/openshift-kube-apiserver/configmaps/config{{end}}API endpoint, filter with with thejqutility using the following filter{{if ne .hypershift_cluster "None"}}.data."config.json" | fromjson{{else}}.data."config.yaml" | fromjson{{end}}and persist it to the local
Rationale
Using the NodeRestriction plugin 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.
- ID
- xccdf_org.ssgproject.content_rule_api_server_admission_control_plugin_noderestriction
- Severity
- Medium
- References
- Updated