Centos7可用的repo文件下载yum源文件

# 删除原yum源
rm -rf /etc/yum.repos.d/*

# wget命令下载: wget [options] 

wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
# curl命令下载: curl [options] 

curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

# 清除yum缓存
yum clean all
# 缓存阿里云镜像
yum makecache

# 创建shell脚本文件
vi /opt/aliyun_yum.sh