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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):

<cli bash> # 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 </cli>

To install the latest version, run (as root): <cli> apt install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin </cli>

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:

<cli> 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. </cli>

take note of the token provided

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

<cli> root@docker01:~# docker swarm join \

1. -token SWMTKN-1-2[snip]wlr \

192.168.99.100:2377 </cli>

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:

<cli> 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...

</cli>

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

<cli> root@docker01:~# docker node ls

ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS dxn1zf6l61qsb1josjja83ngz * manager1 Ready Active Leader </cli>

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.