Gamma, by Teleport

Github Actions Monorepo Magic Automation

Gamma is a tool that sets out to solve a few shortcomings when it comes to managing and maintaining multiple GitHub actions.

What does it do?

• 🚀 No more including the compiled source code in your commits
• 🚀 Automatically build all your actions into individual, publishable repos
• 🚀 Share schema definitions between actions
• 🚀 Version all actions separately

Gamma allows you to have a monorepo of actions that are then built and deployed into individual repos. Having each action in its own repo allows for the action to be published on the Github Marketplace.

Gamma also goes further when it comes to sharing common action.yml attributes between actions. Actions in your monorepo can extend upon other YAML files and bring in their inputs, branding, etc - reducing code duplication and making things easier to maintain.

How to use

This assumes you're using yarn with workspaces. Each workspace is an action.

Your root package.json should look like:

{
  "name": "actions-monorepo",
  "private": true,
  "workspaces": [
    "actions/*"
  ]
}

Each action then lives under the actions/ directory.

Each action should be able to be built via yarn build. We recommend ncc for building your actions. The compiled source code should end up in a dist folder, relative to the action. You should add dist/ to your .gitignore.

actions/example/package.json

{
  "name": "example",
  "version": "1.0.0",
  "repository": "https://github.com/mono-actions/example.git",
  "scripts": {
    "build": "ncc build ./src/index.ts -o dist"
  },
  "dependencies": {
    "@actions/core": "^1.10.0"
  },
  "devDependencies": {
    "@types/node": "^18.8.2",
    "@vercel/ncc": "^0.34.0",
    "typescript": "^4.8.4"
  }
}

The repository field is where the compiled action will deployed to.

actions/example/action.yml

This is where Gamma can really shine. You can define your action.yml as normal, whilst also extending on other YAML files for common attributes.

name: Example Action
description: This is an example action
extend:
  - from: '@/shared/common.yml'
    include:
      - field: inputs
        include:
          - version
      - field: runs
      - field: author
      - field: branding

@/ refers to the root of the directory. @/shared/common.yml would resolve to shared/common.yml, which can look like this:

shared/common.yml

author: Gravitational, Inc.
inputs:
  version:
    required: true
    description: 'Specify the version without the preceding "v"'
branding:
  icon: terminal
  color: purple
runs:
  using: node16
  main: dist/index.js

Gamma will compile this and publish the final action.yml to the correct repository.

github.com/mono-actions/example/action.yml

name: Example Action
description: This is an example action
author: Gravitational Inc.
inputs:
    version:
        description: Specify the version without the preceding "v"
        required: true
runs:
    using: node16
    main: dist/index.js
branding:
    icon: terminal
    color: purple

The built source code will also be committed, so you end up with a publishable Github Action.

Use in GitHub actions

You can use this in your GitHub action workflows via setup-gamma.