Bazel helpers library

Base Starlark libraries and basic Bazel rules which are useful for constructing rulesets and BUILD files.

📚 API documentation: https://registry.bazel.build/modules/bazel_lib

This branch has code for the 3.0 release of bazel_lib, to https://registry.bazel.build/modules/bazel_lib

The module has been renamed from the 2.x releases which used the name "aspect_bazel_lib". Following Aspect's donation to the Linux Foundation, the new name allows more of the community to participate without supporting one vendor. This code is still in the 2.x branch.

These two modules can be used in parallel during a transition. Note that tar, jq and yq have moved to their own modules as part of the 3.0 release.

This module depends on bazel-skylib. In theory all these utilities could be upstreamed to bazel-skylib, but the declared scope of that project is narrow and it no longer accepts feature requests, see https://github.com/orgs/bazelbuild/discussions/3. It's possible that we may instead remove the dependency on bazel-skylib and entirely replace it, in an ABI-compatible sense. See #927.

Installation instructions are included on each release: https://github.com/bazel-contrib/bazel-lib/releases

To use a commit rather than a release, you can point at any SHA of the repo. However, this adds more "dev dependencies", as you'll have to build our helper programs (such as copy_to_directory, expand_template) from their Go sources rather than download pre-built binaries.

For example to use commit abc123 in MODULE.bazel:

# Automatically picks up new Go dev dependencies
git_override(
    module_name = "bazel_lib",
    commit = "abc123",
    remote = "git@github.com:bazel-contrib/bazel-lib.git",
)

Or in WORKSPACE:

1. Replace url = "https://github.com/bazel-contrib/bazel-lib/releases/download/v0.1.0/bazel-lib-v0.1.0.tar.gz" with a GitHub-provided source archive like url = "https://github.com/bazel-contrib/bazel-lib/archive/abc123.tar.gz"
2. Replace strip_prefix = "bazel-lib-0.1.0" with strip_prefix = "bazel-lib-abc123"
3. Update the sha256. The easiest way to do this is to comment out the line, then Bazel will print a message with the correct value.
4. load("@bazel_lib//:deps.bzl", "go_dependencies") and then call go_dependencies()

Note that GitHub source archives don't have a strong guarantee on the sha256 stability, see https://github.blog/2023-02-21-update-on-the-future-stability-of-source-code-archives-and-hashes