bazel_download_archives

v0.1.0

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jjmaestro/bazel_download_archives

BSD 3-Clause "New" or "Revised" License

public

4 assets

32 downloads

38 KB

Bazel central registry

Compatibility level 0

GF6eMoulnM3G+XlosrvjHX0vZFkKoyHffKdUz1d3+eQ=

Maintained byJavier Maestro

Bazel module to help create and maintain Bazel external repos

v0.1.0

September 23, 2025

[expand for release notes]

`download_archives`

Bazel module to help create and maintain Bazel external repos.

📦 Install

First, make sure you are running Bazel with Bzlmod. Then, add the module as a dependency in your MODULE.bazel:

bazel_dep(name = "download_archives", version = "<VERSION>")

Non-registry overrides

If you need to use a specific commit or version tag from the repo instead of a version from the registry, add a non-registry override in your MODULE.bazel file, e.g. archive_override:

REF = "v<VERSION>"  # NOTE: can be a repo tag or a commit hash

archive_override(
    module_name = "download_archives",
    integrity = "",  # TODO: copy the SRI hash that Bazel prints when fetching
    strip_prefix = "bazel_download_archives-%s" % REF.strip("v"),
    urls = ["https://github.com/jjmaestro/bazel_download_archives/archive/%s.tar.gz" % REF],
)

NOTE: integrity is intentionally empty so Bazel will warn and print the SRI hash of the downloaded artifact. Leaving it empty is a security risk. Always verify the contents of the downloaded artifact, copy the printed hash and update MODULE.bazel accordingly.

🚀 Getting Started

download_archives is a repository rule to create and maintain Bazel external repos. It helps reduce boilerplate code by keeping a JSON index file with all of the metadata required to download and extract an archive: the archive's version(s) and the source(s) from which to try to download the archive.

This repository rule wraps rctx.download_and_extract and creates a Bazel repo under @<REPO_NAME>, downloading and extracting one archive from one of the sources for each of the archive versions in the [repo JSON index].

When downloading the archive, if a source fails it will try the next one, and only fail if all sources are exhausted.

On top of just reducing boilerplate code, the download_archives repository rule also adds helper constants and aliases to the Bazel repo. Please read the docs for more information about all of their additional functionality.

Here's an example that shows how to create a @wget_src repo for GNU wget:

1. Create the repo index

First, define a repo.json JSON index file in a package. Don't forget to add a BUILD.bazel file in it if one doesn't already exists).

E.g. for a //third-party/wget package:

mkdir -p third-party/wget
touch third-party/wget/BUILD.bazel

Then add the following to the repo.json file:

{
  "version": 1,
  "sources": {
    "github.com": {
      "owner": "mirror",
      "repo": "wget",
      "tag": "v{version}",
      "url": "https://{source}/{owner}/{repo}/archive/refs/tags/{tag}.tar.gz",
      "strip_prefix": "{repo}-{version}"
    },
    "gitlab.com": {
      "owner": "gnuwget",
      "repo": "wget",
      "tag": "v{version}",
      "filename": "{repo}-{tag}",
      "url": "https://{source}/{owner}/{repo}/-/archive/{tag}/{filename}.tar.gz",
      "strip_prefix": "{filename}"
    }
  },
  "versions": {
    "1.24.5": {
      "integrity": {
        "gitlab.com": "sha256-1Yw1cok0niLv563o07/BrjbCQIflWxK8UFlav9srtcw="
      }
    },
    "1.21.3": {
        "github.com": "sha256-VbH6fHnent2TtbYxbNoatK4RNkY3MVPXokJhRzPZBg8=",
        "gitlab.com": "sha256-3w3ImvW4t/H2eMkZbUH+F1zkARSI3cIJSgJFg4ULPU4="
    }
  }
}

2. Add the `download_archives` repo to `MODULE.bazel`

Then, add the following to MODULE.bazel:

download_archives = use_repo_rule("@download_archives//download/archives:defs.bzl", "download_archives")

download_archives(
    name = "wget_src",
    index = "//third-party/wget:repo.json",
    # NOTE:
    # This is how you would add a custom patch for one of the versions. See
    # "Patching" docs for more information about patches.
    # patches = {
    #    "//third-party/wget/patches:0001-1.24.5-test-patch.patch": ">=1.24.5/*",
    # },
)

3. Test it

To test the Bazel repo, run bazel fetch @wget_src. This will attempt to download and extract all the versions defined in the repo index from the available sources.

And, to list all the targets in the repo, run bazel query @wget_src//....

📄 Docs

💡 Contributing

Please feel free to open issues and PRs, contributions are always welcome! See CONTRIBUTING.md for more info on how to work with this repo.

download_archives