服务器上被新来的小伙伴不知道弄了啥，docker没法用了，具体报错如下：

docker ps -a 
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

找了找解决方法，其实就是关闭docker，再重新启动，具体如下：

service docker stop
systemctl stop docker
systemctl start docker
# 检查发现docker又可以使用了。。。。
docker ps -a 

一些常用的docker命令：

• Docker启动命令1: sudo systemctl start docker

• Docker启动命令2: sudo service docker start

• Docker重启命令1: sudo systemctl restart docker

• Docker重启命令2: sudo service docker restart

• docker关闭命令1: sudo systemctl stop docker

• docker关闭命令2: sudo service docker stop

• 守护进程重启: sudo systemctl daemon-reload

• 设置Docker开机自启动方式1: systemctl enable docker.service

• 设置Docker开机自启动方式2: chkconfig docker on

• 关闭Docker开机启动: systemctl disable docker.service

• 查看是否设置开机启动列表: systemctl list-unit-files | grep enable

参考链接：

1. https://blog.csdn.net/lihongdou/article/details/103307015?utm_medium=distribute.pc_relevant.none-task-blog-title-2&spm=1001.2101.3001.4242