#下载CentOS-Base.repo文件
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

vi /etc/yum.repos.d/CentOS-Base.repo 

#在最后增加:
[centos-sclo-rh]
name=CentOS-7 - SCLo rh
baseurl=http://vault.centos.org/centos/7/sclo/$basearch/rh/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-SIG-SCLo
 
[centos-sclo-sclo]
name=CentOS-7 - SCLo sclo
baseurl=http://vault.centos.org/centos/7/sclo/$basearch/sclo/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-SIG-SCLo


#保存退出后，清除缓存，生成新缓存
yum clean all
yum makecache

#更新yum源
yum update

#检查源是否可用
yum -y install bc

#设置源仓库
yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

参考链接：

https://blog.csdn.net/qq_38768446/article/details/143577521

https://www.cnblogs.com/lxzcloud/p/18349036