删除service

教程剩下的部分不需要helloworld这个service了，所以我们现在可以将它删除掉。

1. 通过ssh登录到manager节点。

2. 运行docker service rm helloworld来删除helloworld服务（service）：

    $ docker service rm helloworld
   
    helloworld
   

3. 运行docker service inspect <SERVICE-ID>来确认service是否被删除。CLI将会返回service无法找到信息。

    $ docker service inspect helloworld
    []
    Error: no such service: helloworld
   

4. 移除service后，task的container会在若干秒后被彻底清楚干净。可以登录到相应的节点上，运行docker ps命令来查看task是否被清理。

    $ docker ps
   
    CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS               NAMES
    db1651f50347        alpine:latest       "ping docker.com"        44 minutes ago      Up 46 seconds                           helloworld.5.9lkmos2beppihw95vdwxy1j3w
    43bf6e532a92        alpine:latest       "ping docker.com"        44 minutes ago      Up 46 seconds                           helloworld.3.a71i8rp6fua79ad43ycocl4t2
    5a0fb65d8fa7        alpine:latest       "ping docker.com"        44 minutes ago      Up 45 seconds                           helloworld.2.2jpgensh7d935qdc857pxulfr
    afb0ba67076f        alpine:latest       "ping docker.com"        44 minutes ago      Up 46 seconds                           helloworld.4.1c47o7tluz7drve4vkm2m5olx
    688172d3bfaa        alpine:latest       "ping docker.com"        45 minutes ago      Up About a minute                       helloworld.1.74nbhb3fhud8jfrhigd7s29we
   
    $ docker ps
       CONTAINER ID        IMAGE                   COMMAND             CREATED             STATUS              PORTS