This is one thing that mesos/aurora got right (the "turing-complete-by-design" config files, written in Python). Templating yaml is like templating html. It works but absolutely sucks at scale if your job is to maintain it.

It's good to know that such an interface could conceivably be built for Kubernetes, using the HTTP API. Even better that it supports any programming language (since it's a network interface); I'd see that as a step-up from aurora configs, in fact.

At some point, I imagine this will become the default way that Smart Organizations build around k8s, once k8s's core API is super-stable and people develop sound frameworks in $POPULAR_LANGUAGE for declaring your configuration.

Then, we can then banish yaml to the same fate as json and xml. One can dream, at least. :)