How to implement CI/CD pipeline on Vercel?

How to implement CI/CD pipeline on Vercel?

Vercel provides powerful CI/CD (Continuous Integration/Continuous Deployment) functionality, enabling developers to automate build, test, and deployment processes. Here's a detailed guide to implementing CI/CD pipelines on Vercel.

Vercel CI/CD Basics

1. Automated Deployment

Vercel implements automated deployment through Git integration:

Supported Git Providers:

• GitHub
• GitLab
• Bitbucket

Deployment Trigger Conditions:

• Pushing code to repository
• Creating Pull Request
• Merging Pull Request to main branch
• Pushing tags

2. Deployment Environments

Vercel supports three deployment environments:

Production:

• Deployed to main domain
• Uses production environment variables
• URL: https://your-project.vercel.app

Preview:

• Generates unique URL for each branch or PR
• Uses preview environment variables
• URL: https://your-project-branch.vercel.app

Development:

• Used for local development
• Uses development environment variables
• Accessed via Vercel CLI

Configuring CI/CD Pipeline

1. Git Integration Setup

Connect Git Repository:

1. Create new project in Vercel Dashboard
2. Select "Import Git Repository"
3. Authorize Vercel to access your Git account
4. Select repository to deploy
5. Configure build settings

Configure Build Settings:

javascript
// vercel.json
{
  "version": 2,
  "buildCommand": "npm run build",
  "outputDirectory": "dist",
  "devCommand": "npm run dev",
  "installCommand": "npm install",
  "framework": null
}

2. Environment Variable Configuration

Configure in Dashboard:

1. Go to project settings
2. Select "Environment Variables"
3. Add environment variables
4. Select applicable environment (Production, Preview, Development)

Configure via CLI:

bash
# Add production environment variable
vercel env add API_KEY production

# Add preview environment variable
vercel env add API_KEY preview

# Add development environment variable
vercel env add API_KEY development

Use in Code:

javascript
const apiKey = process.env.API_KEY;

Test Integration

1. Unit Testing

Configure Test Scripts:

json
// package.json
{
  "scripts": {
    "test": "jest",
    "test:watch": "jest --watch",
    "test:coverage": "jest --coverage"
  }
}

Run Tests in CI:

javascript
// vercel.json
{
  "buildCommand": "npm run build",
  "installCommand": "npm install",
  "scripts": {
    "postinstall": "npm run test"
  }
}

2. Integration Testing

Use Playwright:

bash
npm install -D @playwright/test

javascript
// tests/example.spec.js
import { test, expect } from '@playwright/test';

test('homepage has title', async ({ page }) => {
  await page.goto('https://your-project.vercel.app');
  await expect(page).toHaveTitle(/Your Project/);
});

Configure Test Commands:

json
{
  "scripts": {
    "test:e2e": "playwright test"
  }
}

3. Linting and Code Quality Checks

Configure ESLint:

bash
npm install -D eslint

javascript
// .eslintrc.js
module.exports = {
  extends: ['next/core-web-vitals', 'prettier'],
  rules: {
    'no-console': 'warn',
  },
};

Configure Prettier:

bash
npm install -D prettier

json
// .prettierrc
{
  "semi": true,
  "singleQuote": true,
  "tabWidth": 2
}

Run in CI:

json
{
  "scripts": {
    "lint": "eslint .",
    "format": "prettier --write .",
    "format:check": "prettier --check ."
  }
}

Advanced CI/CD Configuration

1. Custom Build Hooks

Use GitHub Actions:

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

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

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - uses: actions/setup-node@v3
        with:
          node-version: '18'
      - run: npm ci
      - run: npm test
      - run: npm run lint

2. Pre-Deployment Checks

Use Vercel CLI:

bash
# Build check
vercel build --yes

# Deploy to preview environment
vercel --yes

# Deploy to production environment
vercel --prod --yes

3. Conditional Deployment

Branch-Based Deployment:

javascript
// vercel.json
{
  "git": {
    "deploymentEnabled": {
      "main": true,
      "develop": true,
      "feature/*": false
    }
  }
}

Deployment Strategies

1. Blue-Green Deployment

Vercel supports blue-green deployment strategy:

Configure Blue-Green Deployment:

javascript
// vercel.json
{
  "alias": ["your-project.vercel.app"],
  "domains": ["your-project.com"]
}

Workflow:

1. Deploy new version to preview environment
2. Test new version
3. Switch traffic to new version
4. If issues, quick rollback

2. Canary Release

Use Vercel's Traffic Splitting:

javascript
// vercel.json
{
  "alias": ["your-project.vercel.app"],
  "domains": ["your-project.com"],
  "routes": [
    {
      "src": "/(.*)",
      "dest": "/$1"
    }
  ]
}

Implement Canary Release:

1. Deploy new version
2. Gradually increase traffic to new version
3. Monitor metrics
4. Full switch or rollback

3. Rolling Update

Vercel automatically handles rolling updates:

• Zero-downtime deployment
• Gradually replace old version
• Automatic health checks
• Automatic rollback on failure

Monitoring and Notifications

1. Deployment Status Monitoring

View Deployment Status:

bash
# View latest deployments
vercel ls

# View deployment details
vercel inspect <deployment-url>

# View deployment logs
vercel logs <deployment-url>

2. Notification Configuration

Slack Notifications:

1. Configure Slack integration in Vercel Dashboard
2. Select events to notify (deployment success, failure, etc.)
3. Configure notification channel

Email Notifications:

1. Configure email notifications in project settings
2. Select events to notify
3. Add recipient email addresses

Webhook Notifications:

javascript
// vercel.json
{
  "webhooks": [
    {
      "url": "https://your-webhook-endpoint.com/deploy",
      "events": ["deployment.success", "deployment.error"]
    }
  ]
}

Performance Optimization

1. Build Caching

Vercel automatically caches:

• node_modules
• Build artifacts
• Dependency downloads

Optimize Caching:

javascript
// vercel.json
{
  "build": {
    "env": {
      "CACHE_KEY": "custom-cache-key"
    }
  }
}

2. Incremental Builds

Configure Incremental Builds:

javascript
// next.config.js
module.exports = {
  experimental: {
    incrementalCacheHandlerPath: './cache-handler.js',
  },
};

3. Parallel Builds

Vercel supports parallel builds:

• Build multiple projects simultaneously
• Execute build steps in parallel
• Improve build speed

Security Best Practices

1. Environment Variable Security

Don't Hardcode Secrets in Code:

javascript
// ❌ Bad
const apiKey = 'your-api-key-here';

// ✅ Good
const apiKey = process.env.API_KEY;

Use Environment Variables:

• Configure in Dashboard
• Add via CLI
• Regularly rotate secrets

2. Access Control

Configure Team Permissions:

• Set team member roles
• Limit deployment permissions
• Audit deployment history

Use SSO:

• Enable single sign-on
• Centralized access management
• Improve security

3. Dependency Security

Use Dependabot:

yaml
# .github/dependabot.yml
version: 2
updates:
  - package-ecosystem: "npm"
    directory: "/"
    schedule:
      interval: "weekly"

Regularly Update Dependencies:

• Use npm audit to check for vulnerabilities
• Update dependencies promptly
• Use npm ci to install dependencies

Troubleshooting

1. Build Failures

Common Causes:

• Dependency version conflicts
• Missing environment variables
• Test failures
• Insufficient memory

Solutions:

• Check build logs
• Verify dependency versions
• Validate environment variables
• Increase memory limits

2. Deployment Timeouts

Causes:

• Long build times
• Network issues
• Resource limitations

Solutions:

• Optimize build process
• Use incremental builds
• Check network connection
• Upgrade to paid plan

3. Environment Variable Issues

Causes:

• Variables not set
• Incorrect variable names
• Environment mismatch

Solutions:

• Check environment variable configuration
• Verify variable names
• Confirm environment settings
• Redeploy project

Best Practices Summary

1. Branch Strategy

Git Flow:

• main: Production environment
• develop: Development environment
• feature/*: Feature branches
• hotfix/*: Emergency fixes

Trunk-Based Development:

• All development on main branch
• Use feature flags
• Frequent deployments

2. Testing Strategy

Testing Pyramid:

• Unit tests: Fast, many
• Integration tests: Medium number
• E2E tests: Few, critical paths

Test Coverage:

• Set coverage goals
• Monitor coverage changes
• Regularly review test quality

3. Deployment Frequency

Continuous Deployment:

• Automatically deploy tested code
• Fast feedback
• Small, frequent changes

Continuous Delivery:

• Automatically build and test
• Manually trigger deployment
• Better control

4. Monitoring and Alerts

Key Metrics:

• Deployment success rate
• Build time
• Test pass rate
• Error rate

Alert Configuration:

• Deployment failure alerts
• Error rate alerts
• Performance degradation alerts

Through the above configuration and best practices, you can establish an efficient, reliable CI/CD pipeline on Vercel, improving development efficiency and code quality.