Multiple Codeowners Action

Combines multiple CODEOWNERS files into a single one at a specified location

About

This action automatically combines multiple CODEOWNERS files from different parts of your repository into a single, consolidated CODEOWNERS file. It's particularly useful in large projects where code ownership is spread across many teams and directories, helping to reduce clutter and improve maintainability of ownership definitions.

Suppose your repository has the following structure with multiple CODEOWNERS files:

/repository-root
│
├── CODEOWNERS
├── docs/
│   └── CODEOWNERS
├── src/
│   ├── api/
│   │   └── CODEOWNERS
│   └── utils/
│       └── CODEOWNERS
└── tests/
    └── CODEOWNERS

file: CODEOWNERS

# Global fallback
* @global-owner

file: docs/CODEOWNERS

# Documentation
* @docs-team

file: src/api/CODEOWNERS

# API specific files
* @api-team
subfolder @some-dev @some-other-dev

file: src/utils/CODEOWNERS

# Utils folder
* @utils-team

file: tests/CODEOWNERS

# Test files
* @test-team

When you run cbrgm/multiple-codeowners-action on this repository (assuming the default output path .github/CODEOWNERS), it will combine these individual CODEOWNERS files into one.

# THIS FILE IS GENERATED, DO NOT EDIT MANUALLY!
# File generated by https://github.com/cbrgm/multiple-codeowners-action
#
# GitHub Codeowners File
#
# https://help.github.com/articles/about-codeowners/
#
# These owners will be the default owners for everything in
# the repo. Unless a later match takes precedence,
# mentioned account names will be requested for
# review when someone opens a pull request.

* @global-owner
/docs/* @docs-team
/src/api/* @api-team
/src/api/subfolder @some-dev @some-other-dev
/src/utils/* @utils-team
/tests/* @test-team

Inputs

output: Optional - Path where the combined CODEOWNERS file will be written, relative to the repository root. Defaults to .github/CODEOWNERS.
path: Optional - Path to the repository root, if different from the default GitHub Actions workspace. Defaults to . (the root of the repository).
dry-run: Optional - Perform a dry run without actually writing the combined CODEOWNERS file. Defaults to false, meaning the combined CODEOWNERS file will be written by default.

Example Workflow

name: Update Combined CODEOWNERS

on:
  push:
    branches:
      - main
    paths:
      - '**/CODEOWNERS'

jobs:
  update-codeowners:
    runs-on: ubuntu-latest
    steps:
    - name: Check out repository
      uses: actions/checkout@v4
      with:
        fetch-depth: 0 # Necessary for the create-pull-request action

    - name: Combine CODEOWNERS Files
      uses: cbrgm/multiple-codeowners-action@v1
      with:
        output: '.github/CODEOWNERS'

    - name: Create Pull Request
      uses: peter-evans/create-pull-request@v5
      with:
        token: ${{ secrets.GITHUB_TOKEN }}
        branch: update-codeowners-${{ github.run_number }}
        commit-message: Update combined CODEOWNERS file
        title: "Update Combined CODEOWNERS"
        body: "This PR updates the combined CODEOWNERS file."
        draft: false

Local Development

You can build this action from source using Go:

make build

Container Usage

This action can be executed independently from workflows within a container. To do so, use the following command:

podman run --rm -it ghcr.io/cbrgm/multiple-codeowners-action:v1 --help

High-Level Functionality

The action uses a BFS approach to traverse the repository's directory structure, starting from the root. It uses a queue to manage directories that need to be visited. As each directory is visited, the action checks for the presence of a CODEOWNERS file. If found, it processes the file by rewriting the ownership rules relative to the repository root. The rewritten rules from all CODEOWNERS files are combined into a single set of rules.

graph TD
    A[Start Action] --> B[Parse Arguments]
    B --> C[Initialize BFS Queue]
    C --> D{Is Queue Empty?}
    D -- Yes --> E[Generate Combined CODEOWNERS]
    D -- No --> F[Dequeue Directory]
    F --> G[Check for CODEOWNERS File]
    G -- Found --> H[Process CODEOWNERS File]
    H --> I[Add Rules to Consolidated Set]
    G -- Not Found --> J[Enqueue Subdirectories]
    J --> D
    I --> D
    E --> K[Output or Dry Run]
    K --> L[End Action]

Contributing & License

We welcome and value your contributions to this project! 👍 If you're interested in making improvements or adding features, please refer to our Contributing Guide. This guide provides comprehensive instructions on how to submit changes, set up your development environment, and more.

Please note that this project is developed in my spare time and is available for free 🕒💻. As an open-source initiative, it is governed by the Apache 2.0 License. This license outlines your rights and obligations when using, modifying, and distributing this software.

Your involvement, whether it's through code contributions, suggestions, or feedback, is crucial for the ongoing improvement and success of this project. Together, we can ensure it remains a useful and well-maintained resource for everyone 🌍.