The man page for _containers-certs.d(5)_ says that subdirectories of
`/etc/containers/certs.d` should be named `host:port`, however, this is
a bit misleading. It seems instead, the directory name must match the
name of the registry server as specified, so in the case of a server
that supports HTTPS on port 443, where the port would be omitted from
the image name, it must also be omitted from the `certs.d` subdirectory
name.
The _containers-image_ role configures _containers-registries.conf(5)_ and
_containers-cert.d(5)_, which are used by CRI-O (and `podman`).
Specifically, we'll use these to redirect requests for images on Docker
Hub (docker.io) to the internal caching proxy.
In addition to ignoring particular types of filesystems, e.g. OverlayFS,
we can also ignore filesystems by their mount point. This could be
useful, for example, for bind-mounted directories, such as those used on
Kubernetes nodes.
There is no specific playbook or role for Kubernetes. All OS
configuration is done at install time via kickstart scripts, and
deploying Kubernetes itself is done (manually) using `kubeadm init` and
`kubeadm join`.