centos7系统配置阿里yum源

#下载地址: https://mirrors.aliyun.com/centos/ 
#备份(官方源)
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
#清理缓存
yum clean all
#手动清理
rm -rf /var/cache/yum/*
#下载
wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
#或者
curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
#epel扩展源
#下载地址:https://mirrors.aliyun.com/epel/
wget -O /etc/yum.repos.d/epel.repo https://mirrors.aliyun.com/repo/epel-7.repo
#生成缓存
yum makecache