Docker unable to built - no URLs in mirrorlist

[jackty9]

Hi all,
I am following this tutorial here to configure a transparent gateway. I have a VM setup via Azure and tried to build a docker image but it failed with the following message. I tried to Google and Stackoverflow but couldn't find any concrete solution. Did anyone follow this tutorial and face the same problem?

[ericwol-msft]

CentOS Linux 8 had reached the End Of Life (EOL) on December 31st, 2021. It means that 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.

https://techglimpse.com/failed-metadata-repo-appstream-centos-8/