Swarm engine has been integrated in the new version of docker and does not need additional installation
docker swarm init --advertise-addr 192.168.194.137
Use the command prompted above to join to the cluster on node 2
docker swarm join --token SWMTKN-1-42oor9ruw9jv0bqw7vqmm6c29jwo5mnf34xvfn9iwojpor8c4q-bbxltikj5m5r1fnkhezlhjkts 192.168.194.137:2377
Now you can see that there are two nodes in the cluster
Create an overlay network
docker network create --driver overlay --opt encrypted --subnet 10.10.1.0/24 ol_net --attachable
Start nginx service
Finally, I start a Ubuntu container. You can see that this container on node 1 can ping nginx on node 1 and node 2 at the same time