Environment Variables

Environment variables keep sensitive data (database passwords, API keys, secrets) out of your source code. The panel automatically passes PORT to your app — everything else you configure yourself.

The PORT Variable#

When you deploy an app, the panel passes PORT as an environment variable matching the port you specified. Your app should always use it:

const PORT = process.env.PORT || 3000;
app.listen(PORT);

Using a .env File#

The simplest approach for Node.js apps is a .env file in your project directory, loaded with the dotenv package:

Install dotenv:

npm install dotenv

Create .env in your project root (via File Manager or SSH):

DATABASE_URL=postgresql://myuser_mydb_u:password@127.0.0.1:5432/myuser_mydb
API_SECRET=your-secret-key
NODE_ENV=production

Load it at the top of your entry file:

require('dotenv').config();

// Now use process.env.DATABASE_URL etc.
const dbUrl = process.env.DATABASE_URL;

[!WARNING] Never commit .env files to version control. Add .env to your .gitignore.

PM2 Ecosystem File#

For more control, use a pm2.config.js (ecosystem file) in your project root. This lets you set environment variables that PM2 injects directly, without relying on a .env file:

// pm2.config.js
module.exports = {
  apps: [{
    name: 'myapp',
    script: 'server.js',
    env_production: {
      NODE_ENV: 'production',
      PORT: 3000,
      DATABASE_URL: 'postgresql://...',
    }
  }]
};

Start with the ecosystem file via SSH:

pm2 start pm2.config.js --env production
pm2 save

[!NOTE] When using an ecosystem file, start the app manually via SSH. The panel's Deploy App form uses a simpler pm2 start command that doesn't read ecosystem files.

Checking Current Environment#

Via SSH:

pm2 show myuser_myapp
# Look for the "Exec mode" and "Env" sections

Or in your app:

console.log(process.env); // logs all environment variables

Common Variables#

Updating Variables#

After changing your .env file, restart the app:

1. Go to Node.js → your app → Restart
2. Or via SSH: pm2 restart myuser_myapp

Next Steps#

• Deploying a Node.js App
• Connecting to PostgreSQL