Ensure that the admission control plugin AlwaysPullImages is set




Always pull images.


Setting admission control policy to 'AlwaysPullImages' forces every new pod to pull the required images every time. In a multi-tenant cluster users can be assured that their private images can only be used by those who have the credentials to pull them. Without this admission control policy, once an image has been pulled to a node, any pod from any user can use it simply by knowing the image's name, without any authorization check against the image ownership. When this plug-in is enabled, images are always pulled prior to starting containers, which means valid credentials are required.

Credentials would be required to pull the private images every time. Also, in trusted environments, this might increases load on network, registry, and decreases speed.

This setting could impact offline or isolated clusters, which have images pre-loaded and do not have access to a registry to pull in-use images. This setting is not appropriate for clusters which use this configuration.


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 include 'AlwaysPullImages'.


Policy Details

Rule Reference ID: AC_K8S_0021
Remediation Available: No
Resource: kubernetes_pod
Resource Category: Compute
Resource Type: Pod