Introducing Github Actions

In this lesson, discover how GitHub Actions automates your development workflows—CI/CD, DevOps pipelines, and more—directly in your repository. If your team already relies on GitHub for version control, you can seamlessly integrate build, test, and deployment steps without external CI servers.

Built-In Runners: Ubuntu, Windows, and macOS

GitHub Actions provides hosted runners for all major platforms:

Defining Workflows with YAML

Workflows are defined in .github/workflows/*.yml files using simple YAML syntax. They run automatically on events like push, pull_request, or package publishing.

Common Trigger Events

• push
• pull_request
• issues
• release
• registry_package

Automate Pull Request Workflows

Use Actions to comment on PRs, assign reviewers, enforce labels, and ensure policy compliance:

Workflows, Jobs, and Steps

A workflow runs in response to specified events. It consists of one or more jobs, each containing ordered steps that execute on a runner.

name: CI Pipeline
on:
  push:
    branches: [ main ]

jobs:
  test:
    name: Run Tests on ${{ matrix.os }}
    strategy:
      matrix:
        os: [ubuntu-latest, macos-latest, windows-latest]
    runs-on: ${{ matrix.os }}

    steps:
      - name: Checkout code
        uses: actions/checkout@v3

      - name: Setup Node.js
        uses: actions/setup-node@v3
        with:
          node-version: '16'

      - name: Install dependencies
        run: npm ci

      - name: Run unit tests
        run: npm test

• runs-on: Specifies the runner OS.
• strategy.matrix: Launches multiple jobs in parallel.
• Steps execute sequentially: checkout → setup → install → test.

Inspecting Logs and Artifacts

View real-time logs, download test reports, or debug failures in the Actions tab:

Click any job to expand step-by-step logs and access artifacts.

Comparing Runner Types

Choose between GitHub-hosted and self-hosted runners based on your requirements:

Next Steps

You now understand the core concepts: workflows, jobs, steps, triggers, and runner options. Stay tuned for deep dives into:

• Secrets management & environment variables
• Reusable workflows & composite actions
• Custom actions with Docker and JavaScript

Happy automating!

Links and References

• GitHub Actions Documentation
• GitHub Workflow Syntax
• Official GitHub Actions Toolkit