I’ve added shell.nix and some support files to a few projects at work. It’s been very beneficial having these files under version control, and nice to see other team members getting use out of them.
I’d like centralize these files in a separate repository, so instead of keeping a project’s shell.nix version-controlled within the project itself, the project would have a small setup script that locates the appropriate shell.nix file and fetches it. Though shell.nix would be gitignored in the project that uses it, the central repo of shell.nix files would track the version of each shell using git tags.
To flesh the idea out a bit, I’m picturing a workflow like:
- foo 1.0.0 is released
- I write shells/foo/shell.nix and shells/foo/init
- I commit the above files to the central repo and tag the commit
- foo 1.0.1 is released
- a PR in the central repo is automatically created updating the version field in shells/foo/shell.nix
- CI tests/builds the shell
- When the PR is merged, the merge commit is tagged
As a developer with a fresh checkout of project foo, I run foo/bin/nix-init, which does the following:
- search the central repo’s tags for
x.y.zis the version of foo I’ve checked out
- clone central repo, at found tag, to a temporary location
- run something like
central-repo/init foo, which runs
central-repo/shells/foo/init, which in turn knows what kind of foo-specific setup steps are necessary
It would be nice if I could add some automated tests. I’m looking at bats at the moment. I actually like the idea of writing tests in the Nix expression language, but I don’t know if that’s feasible.
A fair amount of this in still only vaguely defined (e.g. what to do when no up-to-date tag is found), but I thought I’d put it out there. I know there’s been discussion of similar ideas here, though what I’m considering is more focused on sharing development environments within a small organization than building out a broader network.