GitHub Actions Cheat Sheet

GitHub Actions is a continuous integration and continuous delivery (CI/CD) platform that allows you to automate your build, test, and deployment pipeline. You can create workflows that build and test every pull request to your repository, or deploy merged pull requests to production.

Key Components

• Workflow: An automated procedure that you add to your repository. Defined by a YAML file in .github/workflows/.

• Event: A specific activity that triggers a workflow run (e.g., push, pull_request, release).

• Job: A set of steps that execute on the same runner. Jobs run in parallel by default.

• Step: An individual task that can run commands or actions. Steps are executed in order.

• Action: A custom application that performs a complex task. Can be written in JavaScript or as a Docker container.

• Runner: A server with the GitHub Actions runner application installed. Can be GitHub-hosted or self-hosted.

• Artifact: Files created during a workflow that can be shared between jobs or downloaded.

• Secret: An encrypted variable stored in your repository, organization, or environment.

Workflow File Structure

yaml
name: Workflow Name # Name of the workflow
on: [push, pull_request]               # Events that trigger the workflow
env:                                   # Environment variables for all jobs
  NODE_VERSION: '20'
jobs:                                  # Jobs that make up the workflow
  build-job:                           # Unique job identifier
    runs-on: ubuntu-latest             # Runner environment
    steps:                             # Steps that define the job
      - name: Checkout code            # Step name
        uses: actions/checkout@v4      # Action to use
      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:                          # Input parameters for the action
          node-version: ${{ env.NODE_VERSION }}
      - name: Run tests
        run: npm test                  # Command to execute