配置好后 重新加载一下 daemon
[root@centos-linux jimmy]# systemctl daemon-reload [root@centos-linux jimmy]# systemcel restart docker
重启后，docker pull 就会有飞一般的感觉
如果报错下面的错，可以将 json 改成 .conf
Job for docker.service failed because the control process exited with error code. See "systemctl status docker.service" and "journalctl -xe" for details.
解决办法：将 /etc/docker/daemon.json 修改为 /etc/docker/daemon.conf
mv /etc/docker/daemon.json /etc/docker/daemon.conf
