CI/CD Introduction - Automation with GitHub Actions

What You’ll Learn in This Tutorial

✓ GitHub Actions basics
✓ Workflow definition
✓ Test automation
✓ Deployment automation
✓ Secret management

Step 1: Basic Workflow

# .github/workflows/ci.yml
name: CI

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  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 tests
        run: npm test

      - name: Run build
        run: npm run build

Step 2: Matrix Build

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

Step 3: Deployment Workflow

# .github/workflows/deploy.yml
name: Deploy

on:
  push:
    branches: [main]

jobs:
  deploy:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '20'

      - run: npm ci
      - run: npm run build

      - name: Deploy to Vercel
        uses: amondnet/vercel-action@v25
        with:
          vercel-token: ${{ secrets.VERCEL_TOKEN }}
          vercel-org-id: ${{ secrets.VERCEL_ORG_ID }}
          vercel-project-id: ${{ secrets.VERCEL_PROJECT_ID }}
          vercel-args: '--prod'

Step 4: Conditional Execution

jobs:
  deploy:
    runs-on: ubuntu-latest
    if: github.ref == 'refs/heads/main'

    steps:
      - uses: actions/checkout@v4

      - name: Deploy
        run: ./deploy.sh
        env:
          API_KEY: ${{ secrets.API_KEY }}

Step 5: Using Cache

- name: Cache node modules
  uses: actions/cache@v4
  with:
    path: ~/.npm
    key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
    restore-keys: |
      ${{ runner.os }}-node-

Setting Up Secrets

1. Repository → Settings → Secrets and variables → Actions
2. New repository secret
3. Enter name and value
4. Reference in workflow with ${{ secrets.NAME }}

Summary

Automate testing, building, and deployment with GitHub Actions to improve development efficiency and quality.