Environment Variables

Environment variables let you configure your services without hardcoding values into your code. They're essential for managing API keys, database URLs, feature flags, and any configuration that changes between environments.

Accessing Environment Variables

Variable Scopes

The Variables tab organizes environment variables into three scopes, shown as tabs with count badges:

Service Variables

Variables specific to this instance only. The badge shows the count (e.g., "4" in the screenshot). Use these for:

• Instance-specific credentials
• Configuration unique to this service
• Overrides for shared variables

Shared Variables

Variables available to all services in the project. Use these for:

• Common API keys used across services
• Environment identifiers (ENVIRONMENT=production)
• Feature flags that apply globally
• Service discovery URLs

Connection Variables

Variables that link this instance to other services in your project. The badge shows active connections (e.g., "2"). CloudStation automatically manages these when you connect services.

Managing Variables

Action Buttons

At the top of the variables list, you'll find three action buttons:

• Copy .env - Download all variables in .env format for local development
• Import - Import variables from a file
• + Add Variable - Add a new key-value pair

Variables Table

The table displays your variables with three columns:

Adding Variables

Common Use Cases

Database Connections

DATABASE_URL=postgresql://username:password@hostname:5432/database
DB_HOST=postgres.internal
DB_PORT=5432
DB_NAME=myapp

API Keys and Secrets

STRIPE_API_KEY=sk_live_abc123xyz
SENDGRID_API_KEY=SG.abc123xyz
JWT_SECRET=your-256-bit-secret

Application Configuration

NODE_ENV=production
LOG_LEVEL=info
ENABLE_ANALYTICS=true

Reading Variables in Code

const apiKey = process.env.API_KEY;
const port = process.env.PORT || 3000;

import os

api_key = os.environ.get('API_KEY')
port = int(os.environ.get('PORT', 3000))

$apiKey = getenv('API_KEY');
$port = getenv('PORT') ?: 3000;

import "os"

apiKey := os.Getenv("API_KEY")
port := os.Getenv("PORT")

Best Practices

Naming Conventions

• UPPERCASE_WITH_UNDERSCORES: Standard convention
• Descriptive: DATABASE_URL not DB
• Prefixed: Group related vars (STRIPE_API_KEY, STRIPE_WEBHOOK_SECRET)

Security

• Mark all sensitive values as secrets
• Use different credentials per environment
• Never commit secrets to Git
• Use the Copy .env feature for local development instead of copying values manually

Troubleshooting

Variable Not Working

1. Service not restarted: Changes require restart
2. Typo in variable name: Check exact spelling and case
3. Wrong scope: Ensure the variable is in the correct scope tab (Service vs Shared)
4. Accessing incorrectly: Verify how your framework reads env vars

Next Steps

• Add persistent storage - Configure volumes for data persistence
• Monitor your services - Set up logging and alerts
• Deploy services - Launch new instances with your configuration