Templating dockerfiles

[diegoferigo]

After the last master merge, the Dockerfiles for master and devel are even more similar. For maintainability it might be worth considering the switch to templates in order to reduce code duplication.

I see different choices here:

• Plain CMake exploiting file and configure_file (Example)
• mustache, liquid, EmPy
• A mix of the previous ones

CMake is very powerful for moving and creating files, we have big experience with it, but it might be cumbersome having a decent configuration file (and I'm thinking a yaml file).

Logic-less engines like mustache might do the work, and most of these kind of engines support out-of-the-box readable configuration files.

For what concerns multiplatform support, if we go towards non-CMake solutions, exploiting python or a meta-solution like a slim docker image to generate docker images would work.