Install DataSet Agent on Centos 8

Centos 8 reached EOL at the end of 2021.

https://www.centos.org/centos-linux-eol/

As a result, you may run into agent installation issues on Centos 8 caused by the mirrorlist.

Error: Failed to download metadata for repo 'AppStream': Cannot prepare internal mirrorlist: No URLs in mirrorlist

The agent installer script installs the agent dependencies and that will fail in the case that the system YUM repository isn't working. This issue surfaces after CentOS 8 went EOL when CentOS 8 repos were disabled.

The workaround is to execute the following commands to use baseurl instead of mirrorlist.

sudo sed 's~mirror.centos.org~vault.centos.org~g' -i /etc/yum.repos.d/CentOS-Base.repo
sudo sed 's~mirror.centos.org~vault.centos.org~g' -i /etc/yum.repos.d/CentOS-AppStream.repo
sudo sed 's~#baseurl~baseurl~g' -i /etc/yum.repos.d/CentOS-Base.repo
sudo sed 's~#baseurl~baseurl~g' -i /etc/yum.repos.d/CentOS-AppStream.repo
sudo sed 's~mirrorlist=~#mirrorlist=~g' -i /etc/yum.repos.d/CentOS-Base.repo
sudo sed 's~mirrorlist=~#mirrorlist=~g' -i /etc/yum.repos.d/CentOS-AppStream.repo
sudo sed 's~http~https~g' -i /etc/yum.repos.d/CentOS-AppStream.repo
sudo sed 's~http~https~g' -i /etc/yum.repos.d/CentOS-Base.repo 

Please keep in mind that Centos 8 isn't officially supported by the Scalyr agent. The mirror workaround solution may work for the installer script, but in case it doesn't, users can still manually install the agent via the rpm package.