rules_apt

rules_apt

Pitch

A Bazel module extension for downloading a graph of Debian packages

API

module(name = "example")

apt = use_extension("@rules_apt//apt:defs.bzl", "apt")

# Overrides the source to use for this module
# By default, we will use a recent snapshot and the latest distribution
# Non-reproducible remotes can be used but a warning will be printed
apt.sources(
    name = "snapshot-20241101T025324Z",
    urls = ["https://snapshot.debian.org/archive/debian/20241101T025324Z"],
    distribution = "bookworm",
    reproducible = True,
    default = True,
)

# Adds a package to download
# Later, we may allow version requirements, etc
# Downloads are de-duped across sources by using the SHA256 of the package
apt.package(name = "qemu-system-arm")#sources = "snapshot-20241101T025324Z") implicit default
apt.package(name = "qemu-system-x86", sources = "snapshot-20241101T025324Z")

# Use the downloaded packages
# Note: `buildozer` can generate this automatically
# These are convenience symlink repositories to underlying SHA256 repositories
use_repo(apt, "example-qemu-system-arm", "example-qemu-system-arm")

Each package repository would provide:

• @<pkg>//pkg: The original package .deb package
• @<pkg>//pkg:unpacked: The unpacked package (a tar_unpack target on the .deb)
• @<pkg>//data: The data archive from inside the archive (a tar_extract target on the .deb)
• @<pkg>//control: The data from inside the archive (a tar_extract target on the .deb)
• @<pkg>//data:unpacked: The unpacked data (a tar_unpack target on the data.tar.xz)
• @<pkg>//control:unpacked: The unpacked control (a tar_unpack target on the control.tar.xz)
• @<pkg>//data:archives: The recursive data archives using the dependent package labels
• @<pkg>: alias to @<pkg>//data:archives

Implementation

The extension would download the distribution lists from <remote>/dists/<distribution>/<section>/binary-<arch>/Packages.xz. It would parse the downloaded package data, resolve the package dependencies and output a stream of data that can be passed to the attributes of apt_download:

apt_download(
    name = "<sha256-of-pkg>",  # allows de-duping identical package repositories
    urls = ["..."],
    integrity = "...",
    deps = ["@<sha256-of-dependency>"],
)

Usage

The downloaded packages could be used with rules_patchelf.

patchelf_interpreter_unpack(
    name = "patched",
    srcs = ["@example-qemu-system-arm"],
    interpreter = "@rules_patchelf//patchelf/interpreter:debian",
)

However, it would be a generically useful, standalone, ruleset.