Uninstall UCP

Estimated reading time: 2 minutes

Docker UCP is designed to scale as your applications grow in size and usage. You can add and remove nodes from the cluster to make it scale to your needs.

You can also uninstall Docker Universal Control Plane from your cluster. In this case the UCP services are stopped and removed, but your Docker Engines will continue running in swarm mode. You applications will continue running normally.

If you wish to remove a single node from the UCP cluster, you should instead Remove that node from the cluster.

After you uninstall UCP from the cluster, you’ll no longer be able to enforce role-based access control to the cluster, or have a centralized way to monitor and manage the cluster.

After uninstalling UCP from the cluster, you will no longer be able to join new nodes using docker swarm join, unless you reinstall UCP.

To uninstall UCP, log in to a manager node using ssh, and run the following command:

docker container run --rm -it \
  -v /var/run/docker.sock:/var/run/docker.sock \
  --name ucp \
  docker/ucp:3.1.6 uninstall-ucp --interactive

This runs the uninstall command in interactive mode, so that you are prompted for any necessary configuration values.

The UCP configuration is kept in case you want to reinstall UCP with the same configuration. If you want to also delete the configuration, run the uninstall command with the --purge-config option.

Check the reference documentation to learn the options available.

Once the uninstall command finishes, UCP is completely removed from all the nodes in the cluster. You don’t need to run the command again from other nodes.

Swarm mode CA

After uninstalling UCP, the nodes in your cluster will still be in swarm mode, but you can’t join new nodes until you reinstall UCP, because swarm mode relies on UCP to provide the CA certificates that allow nodes in the cluster to identify one another. Also, since swarm mode is no longer controlling its own certificates, if the certificates expire after you uninstall UCP, the nodes in the swarm won’t be able to communicate at all. To fix this, either reinstall UCP before the certificates expire or disable swarm mode by running docker swarm leave --force on every node.

Restore IP tables

When you install UCP, the Calico network plugin changes the host’s IP tables. When you uninstall UCP, the IP tables aren’t reverted to their previous state. After you uninstall UCP, restart the node to restore its IP tables.

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