Error: Failed to download metadata for repo ‘AppStream’

CentOS-8 – AppStream 46 B/s | 38 B 00:00
Error: Failed to download metadata for repo AppStream : Cannot prepare internal mirrorlist: No URLs in mirrorlist

# cat /etc/redhat-release
CentOS Linux release 8.1.1911 (Core)
服务器是 CentOS

解决办法

自2022年1月31日起，CentOS团队从官方镜像中移除CentOS 8的所有包，但软件包仍在官方镜像上保留一段时间。目前被转移到https://vault.centos.org。如需继续运行旧CentOS 8，可以在/etc/yum.repos中更新repos.d，使用vault.centos.org取代mirror.centos.org

sudo sed -i  s/mirrorlist/#mirrorlist/g  /etc/yum.repos.d/CentOS-*
sudo sed -i  s|#baseurl=http://mirror.centos.org|baseurl=http://vault.centos.org|g  /etc/yum.repos.d/CentOS-*

成功

参考：
https://techglimpse.com/failed-metadata-repo-appstream-centos-8/
https://blog.csdn.net/watson2017/article/details/122887710