Automatically update Homebrew taps when you publish new releases to GitHub. Built with Probot.

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Usage

Firstly, you’ll need to install the Tap Release GitHub App. This listens out for any releases, or any changes to the configuration.

Then, add a .github/tap-release.yml configuration file to the GitHub repository where you publish new releases to.

For example, given the following .github/tap-release.yml file in a my-org/app/app.rb repository:

asset: app.zip
tap: my-org/homebrew-app/app.rb
template: |
  class App < Formula
    desc     "$REPO_DESCRIPTION"
    homepage "$REPO_WEBSITE"
    version  "$STABLE_VERSION"
    url      "$STABLE_ASSET_URL"
    sha256   "$STABLE_ASSET_SHA256"

    def install
      prefix.install "app"
    end
  end

When a new release is published to my-org/app (e.g. v4.2.0), containing a app.zip asset, Tap Release would push a commit to the tap formula in the my-org/homebrew-app repository updating it to:

class App < Formula
  desc     "The best app ever"
  homepage "https://github.com/my-org/app"
  version  "v2.4.0"
  url      "https://github.com/my-org/app/releases/download/v4.2.0/app.zip"
  sha256   "f3832d8966dd39f7ae1316195ebb379cf18aece281bc2f7c43dd799130ebf460"

  def install
    prefix.install "app"
  end
end

If you don't use release assets, you can also just use a URL pattern. For example, given the following template for a Node style tap:

url: "https://registry.npmjs.org/app/-/app-$VERSION_NUMBER.tgz"
tap: my-org/homebrew-app/app.rb
template: |
  class App < Formula
    desc     "$REPO_DESCRIPTION"
    homepage "$REPO_WEBSITE"
    version  "$STABLE_VERSION"
    url      "$STABLE_ASSET_URL"
    sha256   "$STABLE_ASSET_SHA256"

    # ...
  end

When a new release is published (e.g. v4.2.0), Tap Release would push a commit to the tap formula in the my-org/homebrew-app repository updating it to:

class App < Formula
  desc     "The best app ever"
  homepage "https://github.com/my-org/app"
  version  "v4.2.0"
  url      "https://registry.npmjs.org/app/-/app-4.2.0.tgz"
  sha256   "f3832d8966dd39f7ae1316195ebb379cf18aece281bc2f7c43dd799130ebf460"

  # ...
end

Template variables

You can use any of the following variables in your formula template, and they'll be substituted when the tap is regenerated:

Variable	Description
$REPO_DESCRIPTION	GitHub repository description.
$REPO_WEBSITE	GitHub repository website, or URL if there isn't one.
$STABLE_VERSION	Tag name of the latest stable release (e.g. v1.0.2).
$STABLE_VERSION_NUMBER	Tag name of the latest stable release, without any preceding v (e.g. 1.0.2).
$STABLE_ASSET_URL	Download URL of the asset from the latest stable release.
$STABLE_ASSET_SHA256	SHA256 of the asset from the latest stable release.
$DEVEL_VERSION	Tag name of the latest pre-release (e.g. v2.0.0-beta.1).
$DEVEL_VERSION_NUMBER	Tag name of the latest pre-release, without any preceding v (e.g. 2.0.0-beta.1).
$DEVEL_ASSET_URL	Download URL of the asset from the latest pre-release.
$DEVEL_ASSET_SHA256	SHA256 of the asset from the latest pre-release.

Asset & URL variables

You can use any of the following variables in the asset and url options, and they'll be substituted for each stable and development release when searching for assets or generating URLs:

Variable	Description
$VERSION	The version (e.g. v1.0.2).
$VERSION_NUMBER	The version without the preceding v (e.g. 1.0.2).

Configuration options

You can configure Tap Release using the following key in your .github/tap-release.yml file:

Key	Required	Description
tap	Required	The path to the Homebrew tap repository that should be updated.
template	Required	The template string to use to generate the tap. Use variables to insert the values from the releases.
asset	Optional	Filename of the asset to use from the release.
url	Optional	URL pattern to generate the download URLs. Use URL variables to insert the values from the release.
branches	Optional	A list of branches that trigger the tap to be updated when the .github/tap-release.yml file is modified. Useful if you want to test the app on a pull request branch. Default is "master".

Tap Release also supports Probot Config, if you want to store your configuration files in a central repository.

Developing

If you have Node v8+ installed locally, you can run the tests, and a local app, using the following commands:

# Install dependencies
yarn

# Run the tests
npm test

# Run the app locally
npm start

If you don't have Node installed, you can use Docker Compose:

# Run the tests
docker-compose run --rm app npm test

Contributing

Third-pary contributions are welcome! 🙏🏼 See CONTRIBUTING.md for step-by-step instructions.

If you need help or have a question, let me know via a GitHub issue.

Deployment

If you want to deploy your own copy of Tap Release, follow the Probot Deployment Guide.

Releasing

Run the following command:

git checkout master && git pull && npm version [major | minor | patch]

The command does the following:

• Ensures you’re on master and don't have local, un-commited changes
• Bumps the version number in package.json based on major, minor or patch
• Runs the postversion npm script in package.json, which:
  • Pushes the tag to GitHub
  • Publishes the npm release
  • Opens the GitHub releases page so you can publish the release notes