Docker 软件包已经包括在默认的 CentOS-Extras 软件源里。因此想要安装 docker，只需要运行下面的 yum 命令：
[root@localhost ~]# yum install docker
查看docker版本
[root@localhost ~]# docker version
Client:
Version: 1.8.3
API version: 1.20
Go version: go1.4.2
Git commit: cedd534-dirty
Built: Fri Jan 22 06:07:01 UTC 2016
OS/Arch: linux/amd64
Server:
Version: 1.8.3
API version: 1.20
Go version: go1.4.2
Git commit: cedd534-dirty
Built: Fri Jan 22 06:07:01 UTC 2016
OS/Arch: linux/amd64
