In this guide I use my previous Ceph cluster that is already installed with Docker to show how to enable Docker Swarm mode.

Let’s begin.
The following guide is applied only to cephcluster1 node.
1. Initiate Docker Swarm mode
docker swarm init –advertise-addr 172.20.20.101
and copy the instructed command.

The following guide is applied to other nodes (cephcluster2 and cephcluster3).
2. Paste and run the copied command.

The following guide is applied only to cephcluster1 node.
3. Verify joined nodes.
docker node ls

4. Docker is now running on Swarm mode.