GitHub Webhooks for Auto Deploy

import express from 'express';
import crypto from 'crypto';
import { execSync } from 'child_process';

const app = express();
app.use(express.json());

const WEBHOOK_SECRET = process.env.GITHUB_WEBHOOK_SECRET;

app.post('/api/deploy', (req, res) => {
  // Verify webhook signature (see next section)
  const signature = req.headers['x-hub-signature-256'];
  const payload = JSON.stringify(req.body);

  const hash = 'sha256=' + crypto
    .createHmac('sha256', WEBHOOK_SECRET)
    .update(payload)
    .digest('hex');

  if (signature !== hash) {
    console.error('Webhook signature verification failed');
    return res.status(401).json({ error: 'Unauthorized' });
  }

  // Only deploy on push events
  if (req.headers['x-github-event'] !== 'push') {
    return res.status(200).json({ message: 'Ignoring non-push event' });
  }

  const branch = req.body.ref.split('/').pop();

  // Only deploy from main branch
  if (branch !== 'main') {
    return res.status(200).json({ message: 'Ignoring non-main branch' });
  }

  console.log('Deploying from branch:', branch);

  try {
    // Execute deployment script
    execSync('bash /home/user/deploy.sh', { stdio: 'inherit' });
    return res.status(200).json({ message: 'Deployment started' });
  } catch (error) {
    console.error('Deployment failed:', error);
    return res.status(500).json({ error: 'Deployment failed' });
  }
});

app.listen(3001, () => {
  console.log('Webhook receiver listening on port 3001');
});

# .env.production
GITHUB_WEBHOOK_SECRET=your_webhook_secret_here_min_32_chars
NODE_ENV=production

# Local testing with ngrok
npm install -g ngrok
ngrok http 3001

# You'll get a URL like: https://abc123.ngrok.io
# Webhook URL would be: https://abc123.ngrok.io/api/deploy

# Or use a reverse proxy on your server
# Configure Nginx to forward requests to your webhook endpoint
location /api/deploy {
  proxy_pass http://localhost:3001;
}

// Handle different GitHub events
app.post('/api/deploy', verifyWebhookSignature, (req, res) => {
  const eventType = req.headers['x-github-event'];
  const payload = req.body;

  console.log('Received GitHub event:', eventType);

  // Only handle push events
  if (eventType !== 'push') {
    console.log('Ignoring event type:', eventType);
    return res.status(200).json({ message: 'Event ignored' });
  }

  // Extract branch and commit info
  const ref = payload.ref; // e.g., "refs/heads/main"
  const branch = ref.split('/').pop(); // "main"
  const commits = payload.commits;
  const pushedBy = payload.pusher.name;

  console.log({
    branch,
    commitsCount: commits.length,
    pushedBy,
    latestCommit: commits[0]?.message
  });

  // Trigger deployment
  triggerDeployment(branch);

  res.status(200).json({ message: 'Deployment triggered' });
});

const triggerDeployment = async (branch) => {
  console.log('Starting deployment from branch:', branch);

  try {
    // Pull latest code
    console.log('Pulling code...');
    execSync('git pull origin ' + branch);

    // Install dependencies
    console.log('Installing dependencies...');
    execSync('npm ci --production');

    // Run tests
    console.log('Running tests...');
    execSync('npm test');

    // Reload with PM2
    console.log('Reloading application...');
    execSync('pm2 reload app.js');

    // Verify health
    await new Promise(resolve => setTimeout(resolve, 2000));
    const health = execSync('curl -f http://localhost:3000/health').toString();
    console.log('Health check passed:', health);

    console.log('Deployment completed successfully!');
  } catch (error) {
    console.error('Deployment failed:', error.message);

    // Rollback on failure
    console.log('Rolling back to previous version...');
    execSync('git reset --hard HEAD~1');
    execSync('npm ci --production');
    execSync('pm2 reload app.js');

    throw error;
  }
};

# In your GitHub repository:
1. Go to Settings → Webhooks
2. Find your webhook in the list
3. Click it to edit
4. Scroll down to "Recent Deliveries"
5. Click "Redeliver" to send a test webhook
6. Check the response and see request/response details

# Terminal 1: Start your Node.js app
npm start

# Terminal 2: Expose with ngrok
ngrok http 3000

# Terminal 3: Configure webhook in GitHub
# Settings → Webhooks → Add webhook
# Payload URL: https://your-ngrok-url.ngrok.io/api/deploy
# Content type: application/json
# Secret: your_webhook_secret
# Events: Push events

# Then test by pushing to your repo
git add .
git commit -m "Test webhook"
git push origin main

# Watch the deployment happen!

import crypto from 'crypto';

const payload = {
  ref: 'refs/heads/main',
  repository: { name: 'myapp' },
  pusher: { name: 'testuser' },
  commits: [{ message: 'Test commit' }]
};

const secret = 'your_webhook_secret';
const payloadString = JSON.stringify(payload);
const signature = 'sha256=' + crypto
  .createHmac('sha256', secret)
  .update(payloadString)
  .digest('hex');

fetch('https://your-domain.com/api/deploy', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'X-Hub-Signature-256': signature,
    'X-GitHub-Event': 'push'
  },
  body: payloadString
})
  .then(res => res.json())
  .then(data => console.log('Response:', data))
  .catch(err => console.error('Error:', err));