Create a swarm
Estimated reading time: 2 minutes
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.
Open a terminal and ssh into the machine where you want to run your manager node. This tutorial uses a machine named
manager1. If you use Docker Machine, you can connect to it via SSH using the following command:
$ docker-machine ssh manager1
Run the following command to create a new swarm:
$ docker swarm init --advertise-addr <MANAGER-IP>
Note: If you are using Docker Desktop for Mac or Docker Desktop for Windows to test single-node swarm, simply run
docker swarm initwith no arguments. There is no need to specify
--advertise-addrin this case. To learn more, see the topic on how to Use Docker Desktop for Mac or Docker Desktop for Windows with Swarm.
In the tutorial, the following command creates a swarm on the
$ docker swarm init --advertise-addr 192.168.99.100 Swarm initialized: current node (dxn1zf6l61qsb1josjja83ngz) is now a manager. To add a worker to this swarm, run the following command: docker swarm join \ --token SWMTKN-1-49nj1cmql0jkz5s954yi3oex3nedyz0fb0xx14ie39trti4wxv-8vxv8rssmk743ojnwacrr2e7c \ 192.168.99.100:2377 To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.
--advertise-addrflag configures the manager node to publish its address as
192.168.99.100. The other nodes in the swarm must be able to access the manager at the IP address.
The output includes the commands to join new nodes to the swarm. Nodes will join as managers or workers depending on the value for the
docker infoto 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 ...snip...
docker node lscommand to view information about nodes:
$ docker node ls ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS dxn1zf6l61qsb1josjja83ngz * manager1 Ready Active Leader
*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.
In the next section of the tutorial, we add two more nodes to the cluster.tutorial, cluster management, swarm mode