centos7 docker启动异常

[root@master ~]# systemctl status docker.service
● docker.service - Docker Application Container Engine
   Loaded: loaded (/usr/lib/systemd/system/docker.service; enabled; vendor preset: disabled)
  Drop-In: /usr/lib/systemd/system/docker.service.d
           └─flannel.conf
        /etc/systemd/system/docker.service.d
           └─http-proxy.conf
   Active: inactive (dead) since Fri 2016-08-12 13:29:48 CST; 8min ago
     Docs: http://docs.docker.com
 Main PID: 3018 (code=exited, status=0/SUCCESS)


Aug 12 13:29:48 master systemd[1]: Stopping Docker Application Container Engine...
Aug 12 13:29:48 master docker[3018]: time="2016-08-12T13:29:48.902541894+08:00" level=info msg="Processing signal 'terminated'"
Aug 12 13:31:19 master systemd[1]: Dependency failed for Docker Application Container Engine.
Aug 12 13:31:19 master systemd[1]: Job docker.service/start failed with result 'dependency'.
Aug 12 13:32:49 master systemd[1]: Dependency failed for Docker Application Container Engine.
Aug 12 13:32:49 master systemd[1]: Job docker.service/start failed with result 'dependency'.
Aug 12 13:34:20 master systemd[1]: Dependency failed for Docker Application Container Engine.
Aug 12 13:34:20 master systemd[1]: Job docker.service/start failed with result 'dependency'.
Aug 12 13:36:32 master systemd[1]: Dependency failed for Docker Application Container Engine.
Aug 12 13:36:32 master systemd[1]: Job docker.service/start failed with result 'dependency'.