推广或降级 Swarm 节点

要提升节点或节点集，请从管理器节点运行 docker node promote：

docker node promote node-3 node-2

Node node-3 promoted to a manager in the swarm.
Node node-2 promoted to a manager in the swarm.

要降级节点或节点集，请从管理器节点运行 docker node demote：

docker node demote node-3 node-2

Manager node-3 demoted in the swarm.
Manager node-2 demoted in the swarm.