⚡ GitHub Actions CI/CD

Automate your build, test, and deployment pipelines using GitHub Actions.

What is GitHub Actions?

GitHub Actions is a CI/CD platform that allows you to automate your build, test, and deployment pipeline directly from your GitHub repository.

Workflow Basics

Workflows are defined in .github/workflows/ directory using YAML files.

Basic Workflow Structure

name: CI Pipeline
 
on:
  push:
    branches: [main, develop]
  pull_request:
    branches: [main]
 
jobs:
  build:
    runs-on: ubuntu-latest
 
    steps:
      - uses: actions/checkout@v4
 
      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: "20"
          cache: "npm"
 
      - name: Install dependencies
        run: npm ci
 
      - name: Run tests
        run: npm test
 
      - name: Build
        run: npm run build

Complete CI/CD Example

Here’s a comprehensive workflow for a Next.js application:

name: CI/CD Pipeline
 
on:
  push:
    branches: [main]
  pull_request:
    branches: [main]
 
env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}
 
jobs:
  # Job 1: Lint and Test
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
 
      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: "20"
          cache: "npm"
 
      - name: Install dependencies
        run: npm ci
 
      - name: Run linter
        run: npm run lint
 
      - name: Run tests
        run: npm run test:ci
        env:
          CI: true
 
  # Job 2: Build Docker Image
  build:
    needs: test
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
 
    steps:
      - uses: actions/checkout@v4
 
      - name: Log in to Container Registry
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}
 
      - name: Extract metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            type=sha
            type=ref,event=branch
 
      - name: Build and push
        uses: docker/build-push-action@v5
        with:
          context: .
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
 
  # Job 3: Deploy
  deploy:
    needs: build
    runs-on: ubuntu-latest
    if: github.ref == 'refs/heads/main'
 
    steps:
      - name: Deploy to production
        run: |
          echo "Deploying to production..."
          # Add your deployment commands here

Useful Actions

Action	Purpose
`actions/checkout@v4`	Checkout repository
`actions/setup-node@v4`	Setup Node.js
`actions/cache@v4`	Cache dependencies
`docker/build-push-action@v5`	Build & push Docker images
`vercel/actions@v1`	Deploy to Vercel

Secrets Management

steps:
  - name: Deploy
    env:
      API_KEY: ${{ secrets.API_KEY }}
      DATABASE_URL: ${{ secrets.DATABASE_URL }}
    run: |
      npm run deploy

Matrix Builds

Test across multiple versions:

jobs:
  test:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        node-version: [18, 20, 22]
 
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: ${{ matrix.node-version }}
      - run: npm ci
      - run: npm test

💡 Tip: Use reusable workflows to share common logic across repositories.

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