source

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 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 example we uses a machine named docker00.

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 192.168.80.10
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 192.168.80.10:2377

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

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

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

root@docker01:~# docker swarm join \
    --token SWMTKN-1-2[snip]wlr \
    192.168.80.10:2377

The –advertise-addr flag configures the manager node to publish its address as 192.168.80.10. 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@docker00:~# docker info
Client: Docker Engine - Community                                                                                                                                                             
 Version:    28.0.1                                                                                                                                                                           
 Context:    default                                                                                                                                                                          
 Debug Mode: false                                                                                                                                                                            
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.21.1
    Path:     /usr/libexec/docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v2.33.1
    Path:     /usr/libexec/docker/cli-plugins/docker-compose

Server:
 Containers: 6
  Running: 3
  Paused: 0
  Stopped: 3
 Images: 6
 Server Version: 28.0.1
 Storage Driver: overlay2
  Backing Filesystem: extfs
  ...snip...
Swarm: active
  NodeID: nh0izhq4pa2plmjdvy00f8um7
  Is Manager: true
  ClusterID: mbwi9gcqsueen8mcanvme3zc8
  Managers: 1
  Nodes: 3
  ...snip...

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

root@docker00:~# docker node ls
ID                            HOSTNAME       STATUS    AVAILABILITY   MANAGER STATUS   ENGINE VERSION
nh0izhq4pa2plmjdvy00f8um7 *   deb-docker00   Ready     Active         Leader           28.0.1
7m0t8hrymi0jlmy1jpf85tknt     deb-docker01   Ready     Active                          28.0.1
tebmpkb8og8ko2jfa2zq0z5oc     deb-docker02   Ready     Active                          28.0.1

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.