Using the hosted discovery service
# create a cluster
$ swarm create
6856663cdefdec325839a4b7e1de38e8 # <- this is your unique <cluster_id>
# on each of your nodes, start the swarm agent
# <node_ip> doesn't have to be public (eg. 192.168.0.X),
# as long as the swarm manager can access it.
$ swarm join --addr=<node_ip:2375> token://<cluster_id>
# start the manager on any machine or your laptop
$ swarm manage -H tcp://<swarm_ip:swarm_port> token://<cluster_id>