1. 10.51上执行 docker swarm init
```
[root@ZD-CRM1 ~]# docker swarm init
Swarm initialized: current node (pbbaiutisn0vsvwt8tfxwusev) is now a manager.

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

    docker swarm join --token SWMTKN-1-2jliqh8rns5afbnzrrwr036p7c0kkj38188290at4xb35zgctg-ek7ku7qskkfiu2pl0dmu8q5v6 192.168.10.51:2377

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

2. 其他机器执行上面的 docker swarm join 

```
  docker swarm join --token SWMTKN-1-2jliqh8rns5afbnzrrwr036p7c0kkj38188290at4xb35zgctg-ek7ku7qskkfiu2pl0dmu8q5v6 192.168.10.51:2377

```

3. 10.51上查看集群情况

```
[root@ZD-CRM1 ~]# docker node ls
ID                            HOSTNAME   STATUS    AVAILABILITY   MANAGER STATUS   ENGINE VERSION
pbbaiutisn0vsvwt8tfxwusev *   ZD-CRM1    Ready     Active         Leader           25.0.1
je9g46e68diiryiz1cddd7765     ZD-CRM2    Ready     Active                          25.0.1
fqim3l4inkscd4px8jzi9j7nc     ZD-CRM3    Ready     Active                          25.0.1
```