r2r-dev / rules_tar_sample

rules_tar example repository

This project serves as an example of how to build a Golang project using Bazel, Gazelle and optionally Nix.

Project consists of two main parts. First a cli tool for creating a tar file from a list of inputs, and printing out file sizes. Secondly two Bazel rules utilizing said cli tool.

Prerequisites:

This project requires UNIX-based environment and Bazel v4.2.1. Depending on your host OS setup, you can fetch all of necessary dependencies using one of the following methods

Nix/NixOS:

nix-shell

Docker/Bazelisk:

docker run -v $(pwd):$(pwd) -w $(pwd) -it nickdecooman/debian-bazelisk:62443c9 bash

cli tool

You can build and run a standalone version of cli tool using:

bazel run //cmd:tarchiver --         --help
bazel run //cmd:tarchiver -- archive --help
bazel run //cmd:tarchiver -- size    --help

Bazel rules

Additionally, this project implements two simple rules utilizing the above cli tool.

pkg_tar

a build rule accepting source files as input and producing a tar archive as an output, with optional prefixed directory structure. This rule is based on archive subcommand of tararchiver utility.

Example:

bazel build //examples:archive
tar tvf bazel-bin/examples/archive.tar

file_size

an executable rule, accepting a single source file and printing out its size in bytes. This rule is based on size subcommand of tararchiver utility.

Example:

bazel run //examples:size