Use the controller to send Varnish bans
Since the controller is based on using CLI connections to manage Varnish instances, it could also be used to issue bans.
Bans are not similar to static configs in k8s, which represent a desired state of the cluster. They resemble Jobs more than anything else in k8s, since they are one-time commands, except Jobs specify executable commands within the container.
Concept: the controller listens at an HTTP endpoint for ban commands; we specify a REST API for that.