Code review comment for lp:~ack/charms/trusty/keystone/pause-and-resume

Thanks for the submission! I think this generally looks good and would be quite pleased to approve it for a single unit operation. However, in the case where keystone is scaled out and paired with the hacluster charm I think we want to do some cluster appropriate operations first (e.g. move resources off-node pre-emptively).

That's probably common code to be shared amongst other charms, but I think we definitely need to consider the scenario in which a service is paused/resumed in a cluster. If its paused and resources are moved away, does it need to be able to ensure that resources cannot be moved back to the node which may cause confusion.

Will mark the review as Needs Information for now while this is sorted.