docker node promote
Promote one or more nodes to manager in the swarm
Swarm This command works with the Swarm orchestrator.
docker node promote NODE [NODE...]
Promotes a node to manager. This command can only be executed on a manager node.
This is a cluster management command, and must be executed on a swarm manager node. To learn about managers and workers, refer to the Swarm mode section in the documentation.
$ docker node promote <node name>