Compute & Database

# Make it usable (run in your terminal)
chmod 400 ~/Downloads/sandbox-key.pem

#!/bin/bash
set -e

# Install Node.js 18
curl -fsSL https://rpm.nodesource.com/setup_18.x | bash -
yum install -y nodejs git

# Install CodeDeploy agent (for later CI/CD module)
yum install -y ruby wget
cd /home/ec2-user
wget https://aws-codedeploy-us-east-1.s3.amazonaws.com/latest/install
chmod +x ./install
./install auto

# Create the application directory
mkdir -p /home/ec2-user/sandbox-app/app
cd /home/ec2-user/sandbox-app/app

# Initialize app and install dependencies
npm init -y
npm install express pg dotenv

# Create the Express server inline
cat > server.js << 'EOF'
const express = require('express');
const { Pool } = require('pg');
const os = require('os');
require('dotenv').config();

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

// Set up Postgres connection pool
const pool = new Pool({
  host: process.env.DB_HOST,
  port: process.env.DB_PORT,
  database: process.env.DB_NAME,
  user: process.env.DB_USER,
  password: process.env.DB_PASSWORD,
});

// The crucial /health endpoint for the ALB
app.get('/health', (req, res) => {
  res.status(200).send('OK');
});

// Provide instance hostname to prove ALB routing
app.get('/api/info', (req, res) => {
  res.json({ hostname: os.hostname(), message: 'Hello from EC2 Auto Scaling!' });
});

// Dummy task API
app.get('/api/tasks', (req, res) => {
  res.json([{ id: 1, title: 'Sample task', description: 'DB not connected in demo' }]);
});

app.post('/api/tasks', (req, res) => {
  res.status(201).json({ status: 'created' });
});

const PORT = process.env.PORT || 3000;
app.listen(PORT, () => console.log(`Server running on port ${PORT}`));
EOF

# Create environment file
cat > .env << 'ENVEOF'
PORT=3000
NODE_ENV=production
DB_HOST=REPLACE_WITH_YOUR_RDS_ENDPOINT
DB_PORT=5432
DB_NAME=sandbox
DB_USER=dbadmin
DB_PASSWORD=REPLACE_WITH_YOUR_RDS_PASSWORD
ENVEOF

# Start the app with PM2
npm install -g pm2
pm2 start server.js --name sandbox
pm2 startup
pm2 save