centos7自建yum源更新服务器

mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
curl -o /etc/yum.repos.d/CentOS-Base.repo https://down.sstp.top/yum/centos7_base.repo
yum clean all
yum makecache