Relationship Between a Deis Cluster and Scale command?
So, I think I can answer my own question now, having successfully gotten a DEIS cluster running on EC2.
To see what is running, where, run (from your Deis directory):
make statusWhich is actually running fleetctl list-units.
That shows the running services in their containers, spread across your cluster. In my instance, I have 3 hosts in my cluster.
If I deploy an app/site, using deis create, then it will deploy 1 instance of that app, on one of my three hosts, inside a Docker container.
If I scale the app, using deis scale, then I will have multiple containers, each running of any of the 3 hosts. They could all be on one of those hosts, or any combination.
So, if you run deis scale web=4 across a 3 host cluster, there will be 4 running instances of the app, not 12.