As far as I can tell, this actually does work, but only in Docker for Mac. I’d been trying to run it in a (Vagrant) Ubuntu 14.04 VM, but it’s not working there.
Any idea what I’d need to tweak to run it in Vagrant? The only difference I know between the two is that in Docker for Mac, I don’t need to use an explicit --advertise-addr for docker swarm init, but in the Ubuntu VM, it complains if I don’t use something. It’s possible that I’m not doing that part right, but I don’t know how to figure that out.