How to Fix CentOS 8 Error: ‘appstream’: Cannot prepare internal mirrorlist

If you got the error message is: Failed to download metadata for repo:

[root@autocontroller ~]# yum update
CentOS-8 - AppStream 70 B/s | 38 B 00:00
Error: Failed to download metadata for repo 'AppStream': Cannot prepare internal mirrorlist: No URLs in mirrorlist

CentOS Linux 8 had reached the End Of Life (EOL) on December 31st, 2021. that’s means CentOS 8 will no longer receive development resources from the official CentOS project. After Dec 31st, 2021, if you need to update your CentOS, you need to change the mirrors to vault.centos.org where they will be archived permanently.

So just follow the steps below to do that: Go to the /etc/yum.repos.d/ directory.

cd /etc/yum.repos.d/

Run the below commands to hash the mirror-list in all yum.repos.d files then replace the existed Baseurl with the vault.centos.org

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

Then run yum update or install any package you want

yum update -y

Thank you...