Composite artifacts

[chouseknecht]

This is the next evolution of the artifact build process. The current proposal and POC that we're working on for building artifacts tightly couples the artifact with a single GitHub repository.

The next logical step is to remove the one to one dependency, and make it possible to assemble an artifact from many repositories, or even from pieces of repositories.

To do this, we would extend the galaxy.yml meta data file described in #957 to include a repositories section. In this new section it would be possible to provide a list of git URLs pointing to external repositories to include in the archive. Maybe we could further break this down, and allow a sublist of directories or files to include or exclude from a given repository.

The Mazer build command would then be extended to process the new repositories section and assemble the archive.

[cutwater]

Isn't it something that can be achieved by using Git submodules?

[chouseknecht]

@cutwater

Probably, yes. But does anyone actually like git submodules?

[cutwater]

AFAIK it's a de facto standard when it comes to working with dependent repositories.
Why we are trying to reinvent the wheel and increase build complexity with feature that has been already implemented in git?