Bridgefog headless-node CoreOS setup

1. Have this repo available locally.

2. Use OMC to launch an instance:

   omc launch ./omc/coreos-stack.digitalocean.scm

3. After this completes, use fleetctl to start the services.

   1. cd into the systemd-units directory.

   2. Also, make sure you have a recent-ish version of fleetctl installed locally.

   3. Set these variables set in your shell (they will be automatically set by direnv [see the .envrc file]):

      FLEETCTL_DRIVER=etcd
      FLEETCTL_ENDPOINT=http://localhost:2379

   4. Then ssh into the node while forwarding port 2379:

      ssh -L 2379:localhost:2379 -l core <IP>

   5. Now you can interact with the node (or more accurately, the whole cluster, via this node), using fleetctl:

      fleetctl list-machines

   6. To start the ipfs and fog-headless-node services, do this (this is where you must be in the systemd-units directory):

      fleetctl start ipfs fog-headless-node@1

      Note: the 1 here in fog-headless-node@1 is an arbitrary ID, not a count or other meaningful value. It can be anything you like.