centos8更换过期阿里源

mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo
yum clean all && yum makecache
先执行，执行之后yum更新或者安装可能报错，继续执行下面的

minorver=8.5.2111
sudo sed -e "s|^mirrorlist=|#mirrorlist=|g" \
         -e "s|^#baseurl=http://mirror.centos.org/\$contentdir/\$releasever|baseurl=https://mirrors.aliyun.com/centos-vault/$minorver|g" \
         -i.bak \
         /etc/yum.repos.d/CentOS-*.repo
最后，更新软件包缓存
sudo yum makecache    

更换清华源可以将域名替换掉试试看

mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.tuna.tsinghua.edu.cn/repo/Centos-vault-8.5.2111.repo
yum clean all && yum makecache
先执行，执行之后yum更新或者安装可能报错，继续执行下面的

minorver=8.5.2111
sudo sed -e "s|^mirrorlist=|#mirrorlist=|g" \
         -e "s|^#baseurl=http://mirror.centos.org/\$contentdir/\$releasever|baseurl=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/$minorver|g" \
         -i.bak \
         /etc/yum.repos.d/CentOS-*.repo
最后，更新软件包缓存
sudo yum makecache    

或使用清华源的文档说明
sed -e "s|^mirrorlist=|#mirrorlist=|g" \
    -e "s|^#baseurl=http://mirror.centos.org/centos/\$releasever|baseurl=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/8.5|g" \
    -e "s|^#baseurl=http://mirror.centos.org/\$contentdir/\$releasever|baseurl=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/8.5|g" \
    -i.bak \
    /etc/yum.repos.d/CentOS-*.repo
最后，更新软件包缓存
sudo yum makecache