DockerCLI/docs/reference/commandline/swarm_join_token.md

swarm join-token

Usage:	docker swarm join-token [--rotate] (worker|manager)

Manage join tokens

Options:
      --help     Print usage
  -q, --quiet    Only display token
      --rotate   Rotate join token

Join tokens are secrets that allow a node to join the swarm. There are two different join tokens available, one for the worker role and one for the manager role. You pass the token using the --token flag when you run swarm join. Nodes use the join token only when they join the swarm.

You can view or rotate the join tokens using swarm join-token.

As a convenience, you can pass worker or manager as an argument to join-token to print the full docker swarm join command to join a new node to the swarm:

$ docker swarm join-token worker
To add a worker to this swarm, run the following command:

    docker swarm join \
    --token SWMTKN-1-3pu6hszjas19xyp7ghgosyx9k8atbfcr8p2is99znpy26u2lkl-1awxwuwd3z9j1z3puu7rcgdbx \
    172.17.0.2:2377

$ docker swarm join-token manager
To add a manager to this swarm, run the following command:

    docker swarm join \
    --token SWMTKN-1-3pu6hszjas19xyp7ghgosyx9k8atbfcr8p2is99znpy26u2lkl-7p73s1dx5in4tatdymyhg9hu2 \
    172.17.0.2:2377

Use the --rotate flag to generate a new join token for the specified role:

$ docker swarm join-token --rotate worker
Succesfully rotated worker join token.

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

    docker swarm join \
    --token SWMTKN-1-3pu6hszjas19xyp7ghgosyx9k8atbfcr8p2is99znpy26u2lkl-b30ljddcqhef9b9v4rs7mel7t \
    172.17.0.2:2377

After using --rotate, only the new token will be valid for joining with the specified role.

The -q (or --quiet) flag only prints the token:

$ docker swarm join-token -q worker

SWMTKN-1-3pu6hszjas19xyp7ghgosyx9k8atbfcr8p2is99znpy26u2lkl-b30ljddcqhef9b9v4rs7mel7t

--rotate

Because tokens allow new nodes to join the swarm, you should keep them secret. Be particularly careful with manager tokens since they allow new manager nodes to join the swarm. A rogue manager has the potential to disrupt the operation of your swarm.

Rotate your swarm's join token if a token gets checked-in to version control, stolen, or a node is compromised. You may also want to periodically rotate the token to ensure any unknown token leaks do not allow a rogue node to join the swarm.

To rotate the join token and print the newly generated token, run docker swarm join-token --rotate and pass the role: manager or worker.

Rotating a join-token means that no new nodes will be able to join the swarm using the old token. Rotation does not affect existing nodes in the swarm because the join token is only used for authorizing new nodes joining the swarm.

--quiet

Only print the token. Do not print a complete command for joining.

Related information

• swarm join