Running Docker Registry in HA Swarm?

I’m exploring the possibilities of Swarm for a HA solution. I have a configuration with three hosts where each is running as a master in the swarm. The swarm should be able to operate while offline and that means that the images cannot be pulled from an online repo so I’m guessing I would have to run a registry service in the swarm, otherwise if an image is not available in a host (in a case of a failover) it cannot be resolved.
Has anyone tried a similar configuration or know what the right solution is? I’m guessing some mirroring is required for all of the replicated registry services to act the same but I’m not familiar with the configuration options of the registry.


EDIT: I’m using Swarm mode but I’m not sure if this sub-forum is for standalone/legacy Swarm only.