Linux cenots 修改yum为国内源

cd /etc/yum.repos.d/
rm -f CentOS-Base.repo CentOS-AppStream.repo CentOS-PowerTools.repo CentOS-centosplus.repo CentOS-Extras.repo
curl -o CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-8.repo
yum makecache