After much work, I've finally managed to automate the process of setting up new servers to run Minecraft Dota. To create your own, spin up a new server running Debian 7 or CentOS 6 and run the following as the root user:
wget -qO- http://barron.nu/install | sh
For more information, check out the Barroncraft Puppet Scripts page. It's rather sparse on documentation at the moment, but more will be added soon. If you run into issues, please report them on the Github issues page or send an email to email@example.com.