[tingzhuxuan@localhost ~]$ docker run hello-world
docker: Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Post "http://%2Fvar%2Frun%2Fdocker.sock/v1.24/containers/create": dial unix /var/run/docker.sock: connect: permission denied.
解决方案：
[tingzhuxuan@localhost ~]$ sudo groupadd docker ##添加docker用户组
[sudo] tingzhuxuan 的密码：
groupadd：“docker”组已存在
[tingzhuxuan@localhost ~]$ sudo gpasswd -a $USER docker ##在docker用户组中添加当前登陆用户
正在将用户“tingzhuxuan”加入到“docker”组中
[tingzhuxuan@localhost ~]$ newgrp docker ##更新用户组
[tingzhuxuan@localhost ~]$ docker ps ##测试docker命令是否可以使用
