The final result
This video shows the experimental prototype with advanced features. The current "stable"/"public" version has no API for RGB-leds yet.
As other people have already figured out, the small development boards are perfectly suited to experiment with clustered hard- and software. The tagline "Yet another…" is a nod towards their inspiration.
This project does hardly cover new ground. Nevertheless in a methodological way answers to inevitable questions are given:
One button to shut them all down!
A major milestone was reached when the formerly hackish cluster setup was fully automated to bootstrap up to 9 Raspberry Pi 2 Model B or Raspberry Pi 3 Model B into a networked cluster. All in a way to define the infrastructure in code and make remote execution within the cluster possible.