centos8 Failed to download metadata for repo ‘base‘: Cannot download repomd.xml

# 查看系统信息
cat /etc/redhat-release

# centos8更换国内源(阿里源)
# 1. 备份配置文件
sudo mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
# 2.下载新的CentOS-Base.repo到 /etc/yum.repos.d/
sudo wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-8.repo
# 3.替换部分字段(阿里云不需要)
sudo sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo
# 生成缓存
yum makecache