Creating a swarm from various servers on the network


Wanted to figure out if I’m on the right track, since my current solution seems very convoluted.

I want to connect 3 servers, that we have on the local company network. I have free reign over what kind of OS I want to put on them so I first attempted to use Ubuntu Server 16.04. After installing the OS I added a passwordless sudo user, set up his ssh keys, copied the required private key to my personal machine and then tried to register this server to my locally installed docker-machine with the generic driver. After installing docker, the server couldn’t run the docker daemon.

So for my second attempt I tried the exact same process, only using Ubuntu server 14.04. Now the docker-machine properly registered, and I got it running with the generic driver.

I repeated the steps with the remaining 2 servers and now I had all 3 registered in my local docker-machine.

Afterward I created a working swarm and it seems to be working fine.

So my main question is, could I have done this easier somehow?
I tried running boot2docker on those 3 servers, but it always creates new ssh settings on boot, even after I dd the OS on to the hard drive.