@mveerdonk without knowing what steps you’ve taken in the guide to installing, I would ask that you confirm elasticsearch is installed and running on your CentOS system, also, do you have SE linux running? if so, have you taken the necessary steps with regards to SE linux? Have you opened the firewall? Also, is everything running on a single node?
@dickinsonzach CentOS is not sunset, it has been repositioned in the Red Hat hierarchy with the release of CentOS 8. CentOS 7 will see full support until sometime in 2024, so you still have life on that platform. Red Hat has also changed the lincensing for RHEL to allow for a certain number of free installs per account.