moby--moby/docs/swarm/swarm-tutorial/create-swarm.md

Create a swarm

After you complete the tutorial setup steps, you're ready to create a swarm. Make sure the Docker Engine daemon is started on the host machines.

1. Open a terminal and ssh into the machine where you want to run your manager node. For example, the tutorial uses a machine named manager1.

2. Run the following command to create a new swarm:

   docker swarm init --listen-addr <MANAGER-IP>:<PORT>
   

   In the tutorial, the following command creates a swarm on the manager1 machine:

   $ docker swarm init --listen-addr 192.168.99.100:2377
   No --secret provided. Generated random secret:
     4ao565v9jsuogtq5t8s379ulb
   
   Swarm initialized: current node (dxn1zf6l61qsb1josjja83ngz) is now a
   manager.
   
   To add a worker to this swarm, run the following command:
     docker swarm join --secret 4ao565v9jsuogtq5t8s379ulb \
     --ca-hash sha256:07ce22bd1a7619f2adc0d63bd110479a170e7c4e69df05b67a1aa2705c88ef09 \
     192.168.99.100:2377
   

   The --listen-addr flag configures the manager node to listen on port 2377. The other nodes in the swarm must be able to access the manager at the IP address.

   The --ca-hash flag provides the identity of the root CA for the manager node.

3. Save the output of docker swarm init that includes the command to join worker nodes to the swarm.

4. Run docker info to view the current state of the swarm:

   $ docker info
   
   Containers: 2
   Running: 0
   Paused: 0
   Stopped: 2
     ...snip...
   Swarm: active
     NodeID: dxn1zf6l61qsb1josjja83ngz
     Is Manager: true
     Managers: 1
     Nodes: 1
     CA Certificate Hash: sha256:b7986d3baeff2f5664dfe350eec32e2383539ec1a802ba541c4eb829056b5f61
     ...snip...
   

5. Run the docker node ls command to view information about nodes:

   $ docker node ls
   
   ID                           HOSTNAME  MEMBERSHIP  STATUS  AVAILABILITY  MANAGER STATUS  LEADER
   dxn1zf6l61qsb1josjja83ngz *  manager1  Accepted    Ready   Active        Reachable       Yes
   
   

   The * next to the node id indicates that you're currently connected on this node.

   Docker Engine swarm mode automatically names the node for the machine host name. The tutorial covers other columns in later steps.

What's next?

In the next section of the tutorial, we'll add two more nodes to the cluster.