centos7安装docker，更换阿里源

1）yum更换为阿里源

cd /etc/yum.repos.d

#备份原来的

mv CentOS-Base.repo CentOS-Base.repo.bak

#下载阿里的yum源配置文件

wget -O CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

#生成缓存

yum clean all

yum makecache

2）安装doctor

yum -y install docker

#启动docker

systemctl start docker

#查看

systemctl status docker

#开机自启

systemctl enable docker