CoreOS

We only use Ansible for some limited cluster-management, irregular maintenance tasks and low-level docker debugging and re-configuration on the individual servers, as we chose CoreOS (Fedora CoreOS) as our operating system and setup is done with an ignition-configuration. That is why we don't need to have a playbook for setting up servers or individual services. The servers boot up, completely initialized and ready to use.

As the basis of our new infrastructure, we formerly used CoreOS (and transitioned towards Fedora CoreOS as CoreOS was reaching its EOL) as a reliable solution for our docker-server-instances. We plan to deploy all our servers as individual docker containers to make use of the extensive possibilties offered in terms of isolation, resource-managemant (cgroups) and scalability.

The additional abstraction through containers allows us to adhere very closely to the "Cattle not Pets" best practice. Serverless was also an option that we considered, but as running Minecraft-Server requires quite unique resource profiles, that are usually not covered at most cloud providers, we settled with CoreOS for the time being and will reevaluate our options in the years to come.