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Before you install Docker Engine for the first time on a new host machine, you need to set up the Docker apt repository. Afterward, you can install and update Docker from the repository.

To setup official's Docker repository, run (as root):

# Add Docker's official GPG key:
apt update
apt install ca-certificates curl
install -m 0755 -d /etc/apt/keyrings
curl -fsSL https://download.docker.com/linux/debian/gpg -o /etc/apt/keyrings/docker.asc
chmod a+r /etc/apt/keyrings/docker.asc

# Add the repository to Apt sources:
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/debian \
  $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | \
  tee /etc/apt/sources.list.d/docker.list > /dev/null
apt update

To install the latest version, run (as root):

apt install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

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.

Run the following command to create a new swarm:

docker swarm init --advertise-addr <MANAGER-IP>

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

root@docker01:~# 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-1-2[snip]wlr 192.168.99.100:2377

To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.

take note of the token provided

To add a worker to this swarm, run the following command:

root@docker01:~# docker swarm join \
    --token SWMTKN-1-2[snip]wlr \
    192.168.99.100:2377

To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.

The –advertise-addr flag 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 –token flag.

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

root@docker01:~# docker info

Containers: 2
Running: 0
Paused: 0
Stopped: 2
  ...snip...
Swarm: active
  NodeID: dxn1zf6l61qsb1josjja83ngz
  Is Manager: true
  Managers: 1
  Nodes: 1
  ...snip...

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

root@docker01:~# docker node ls

ID                           HOSTNAME  STATUS  AVAILABILITY  MANAGER STATUS
dxn1zf6l61qsb1josjja83ngz *  manager1  Ready   Active        Leader

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

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