Docker 安装后 报 Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running? 解决办法

1.看 /etc/docker/daemon.json 的配置

{
  "registry-mirrors":["https://---.mirror.ali---yuncs.com"]
}

解决办法
$ systemctl daemon-reload
$ sudo service docker restart
$ sudo service docker status (should see active (running))
$ sudo docker run hello-world