Glob for Repository Rules

[cpsauer]

Hi wonderful Bazelers,

Description of the feature request:

It'd be handy if there were a glob function on repository_ctx and/or path--similar semantically to the glob functions otherwise, but runnable in repository rules and returning paths.

What underlying problem are you trying to solve with this feature?

As in BUILD files, glob is often ergonomically nice and encourages simple code, especially because of the prohibition on recursion. The path API does exist, as does the ability to exec arbitrary programs, but I'm filing this because I'd seen a couple places in a row where more complex code was written (in the recently released Blaze ndk rules, for example) because this didn't exist.

Thanks!
Chris
(ex-Googler)

[comius]

cc @meteorcloudy @Wyverald

glob is a rather complex function, and I don't see it immediately how it would work with repository rules. Also wouldn't like to make repository rules over complex.

I think that repository rules should be whenever possible avoided in favour of producing "pure" bzlmod modules.

Extending repository rules with a function that does dir listing might be a better option if the uses are really that complex.
@cpsauer would you mind providing some links to the complex code you're referring to?

P4 for now, possibly P3 if we come up with a viable design.

[mvgijssel]

I’m also interested in this to be able to do Bazel integration testing, globing all files inside a directory using a repository rule and using that workspace to run tests in using Bazel itself.

[mvgijssel]

And now a second use case came up for building a docker image using a Docker file and wanting to glob all the files necessary for the context.