Environment Variables — .env Secrets Management

Instead of accessing process.env everywhere in your code, create a centralized config file. This makes your code cleaner, gives you a single place to manage defaults and validation, and makes testing easier.

// config/index.js — Centralized Configuration
import 'dotenv/config';

const config = {
  // Server
  port: parseInt(process.env.PORT) || 3000,
  nodeEnv: process.env.NODE_ENV || 'development',
  isProduction: process.env.NODE_ENV === 'production',
  isDevelopment: process.env.NODE_ENV === 'development',

  // MongoDB
  mongo: {
    uri: process.env.MONGO_URI || 'mongodb://localhost:27017/dev-in-hyderabad',
    options: {
      maxPoolSize: 10,
      serverSelectionTimeoutMS: 5000
    }
  },

  // JWT
  jwt: {
    secret: process.env.JWT_SECRET,
    expiresIn: process.env.JWT_EXPIRES_IN || '7d',
    get secretWarning() {
      if (!this.secret || this.secret === 'your-secret-here') {
        console.warn('⚠️  WARNING: JWT_SECRET is not set! Using INSECURE default!');
        console.warn('   Set JWT_SECRET in your .env file!');
      }
      return this.secret;
    }
  },

  // Email
  email: {
    user: process.env.EMAIL_USER,
    password: process.env.EMAIL_PASSWORD,
    host: process.env.EMAIL_HOST || 'smtp.gmail.com',
    port: parseInt(process.env.EMAIL_PORT) || 587,
    from: process.env.EMAIL_FROM || 'noreply@devinhyderabad.com'
  },

  // File Upload
  upload: {
    dir: process.env.UPLOAD_DIR || 'uploads',
    maxFileSize: parseInt(process.env.MAX_FILE_SIZE) || 5 * 1024 * 1024,
    allowedTypes: ['image/jpeg', 'image/png', 'image/webp', 'image/gif']
  },

  // App
  app: {
    url: process.env.APP_URL || 'http://localhost:3000',
    name: 'DevInHyderabad Swiggy',
    version: '1.0.0'
  }
};

// Validate required config on startup
const validateConfig = () => {
  const required = [
    { key: 'MONGO_URI', value: config.mongo.uri, desc: 'Database URL' },
    { key: 'JWT_SECRET', value: config.jwt.secret, desc: 'JWT signing secret' },
  ];

  let missing = false;
  for (const { key, value, desc } of required) {
    if (!value || value === 'your-secret-here') {
      console.error('❌ MISSING REQUIRED ENV: ' + key + ' (' + desc + ')');
      console.error('   Add it to your .env file!');
      missing = true;
    }
  }

  if (missing) {
    console.error('\n⚠️  App may not work correctly without required env vars!');
  }
};

validateConfig();

export default config;

Using config in your code:

// Instead of: process.env.MONGO_URI everywhere
// Use config!

import config from './config/index.js';

// Connect to MongoDB
await mongoose.connect(config.mongo.uri, config.mongo.options);

// Start server
app.listen(config.port, () => {
  console.log('Server running in ' + config.nodeEnv + ' mode on port ' + config.port);
});

// Check environment
if (config.isProduction) {
  console.log('🔥 Production mode! Running at ' + config.app.url);
} else {
  console.log('🧪 Development mode at http://localhost:' + config.port);
}

Benefits of centralized config:

• Single source of truth — All config in one place
• Type conversion — parseInt(), JSON.parse() once, not everywhere
• Validation — Check required vars on startup, fail early
• Defaults — Sensible fallbacks for development
• Documentation — One file shows ALL available config