1、查看/usr/lib/systemd/system/docker.service配置

cat /usr/lib/systemd/system/docker.service

 2、将/usr/lib/systemd/system/docker.service配置中[Service]下ExecStart修改成

[Service]
ExecStart=/usr/bin/dockerd -H tcp://0.0.0.0:2375 -H unix://var/run/docker.sock

3、重新加载&重启 

systemctl daemon-reload && systemctl restart docker

遇到问题：如果启动时有如下错误

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： 

# 进入docker目录
cd /etc/docker/
# 修改daemon的类型
mv daemon.json daemon.conf
# 重启docker
systemctl restart docker