Multiple Docker Machines

There are special cases in which you may want to have multiple Docker Hosts running, or use a Docker Machine from another client/project. One example of this might be to test the performance differences between VirtualBox and xhyve.

For these cases, all devtools commands that interact with a Docker Host take a --name flag that will allow you to specify name of the Docker Host. For all commands this name defaults to dev but you can configure this name if needed.
Also, if you don't want to specify the Docker Host name on every command you can specify the DEVTOOLS_ACTIVE_MACHINE environment variable to be Docker Machine name of the VM you care to interact with. This way you can set it once and forget about it. Unless otherwise specified, the name defaults to dev for all commands.