Best practice - Git + Build automation - Keeping configs separate

Question

Searching for the best approach to keep my config files separate, yet not introduce extra steps for new developers setting up their environments.

I am guessing a submodule would suffice to do the job, but then how would I switch configs seamlessly depending on the task at hand, aka pull in DEV config regularly, pull PROD branch of config repo during build?

Needs to be:

• Easy and painless for new devs.
• PROD config files should only be accessible to select users + build user.

Thank you in advance.

Answer 1

That is called content filter driver, and it allows you to declare, in a .gitattributes file (and only for your config files type) a smudge script which will automatically on checkout:

• combine a config file template file (config.tpl)
• with the right config file value (config.dev, config.prod, ...)
• in order to produced a non-versioned config file (private file)

See "Customizing Git - Git Attributes":

echo '*.cfg.tpl filter=config' >> .gitattributes
git config --global filter.config.smudge yourScript

With that approach, you don't need submodules, but you can generate as many config file you need depending on your environment, like for instance your branch:
A bit like in "Find Git branch name in post-update hook", your smudge script can find out in which branch it is currently executing with:

#!/bin/sh
branch=$(git rev-parse --symbolic --abbrev-ref HEAD)