Error: Failed to download metadata for repo ‘AppStream‘: Cannot download repomd.xml解决方法

最近在使用阿里云ESC服务器去下载软件时出现了这个错误，最后在官方上找到了答案
Error: Failed to download metadata for repo ‘AppStream’: Cannot download repomd.xml: Cannot download repodata/repomd.xml: All mirrors were tried
解决方法
‘https://help.aliyun.com/document_detail/405635.html?spm=5176.smartservice_service_chat.0.0.712c3f1bBoZ19I
按照步骤做即可解决 其实是第三方的镜像站中均已移除CentOS 8的源