解决非root用户使用docker的办法

docker命令默认只能root使用的，但我们可以赋权给其他用户。

关于此问题的官方说法如下：

The docker daemon binds to a Unix socket instead of a TCP port. By default that Unix socket is owned by the user root and other users can access it with sudo. For this reason, docker daemon always runs as the root user. 
To avoid having to use sudo when you use the docker command, create a Unix group called docker and add users to it. When the docker daemon starts, it makes the ownership of the Unix socket read/writable by the docker group.

下面是使用非root用户操作的步骤

创建docker组

groupadd docker

将当前用户加入docker组

usermod -G docker user

重新启动docker服务

service docker restart

然后该用户即可使用docker命令