Yes, I'd consider separating template logic as helpful. One could think about docker app for managing the configuration.
I'm not a huge fan of custom setups that work differently from 'normal docker' (Looking at you discourse). Besides separating the template, I propose using a scriptable interface between the templates and the configuration e.g. for assembling common strings or checking the (semantic) validity of the config file. Using the python-like language starlark could be an idea.

Yes, I'd consider separating template logic as helpful. One could think about [docker app](https://github.com/docker/app) for managing the configuration. I'm not a huge fan of custom setups that work differently from 'normal docker' (Looking at you discourse). Besides separating the template, I propose using a scriptable interface between the templates and the configuration e.g. for assembling common strings or checking the (semantic) validity of the config file. Using the python-like language [starlark](https://github.com/google/starlark-go/) could be an idea.