1.1.11 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 images 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.


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'.


See Also