Hi, OP author here: I have actually set up a VRRP (well, UCARP) on Docker, so it's possible even to containerize this facet of running a HA ops stack with Docker as the infrastructure. It is however, as you say, it is only used for one active node + a number of fail-overs in case that one goes down. In terms of maintenance (hosts do go down, scheduled downtime is common), it's priceless to have this part of the puzzle portable as well. If you want to check it out, there's a github available here: https://github.com/titpetric/ucarp-ha - and a future article with it is planned as well. It will also become a part of the E-book which I'm currently working on and publishing on leanpub: https://leanpub.com/12fa-docker-golang :)

OK so that runs on the host to the Docker instances. Pretty cool!