How to Secure Your Fly.io App
Last updated: January 12, 2026
Fly.io enables global edge deployment. This guide covers securing applications deployed across Fly.io's global network.
Step-by-Step Security Guide
1. Manage Secrets Properly
Use 'fly secrets set' to store secrets. They're encrypted and synced across regions automatically.
fly secrets set DATABASE_URL=postgres://...2. Configure Private Networking
Use Fly's private network for service-to-service communication. Don't expose internal services publicly.
3. Secure Volume Data
Data on Fly volumes persists. Encrypt sensitive data at the application level if needed.
4. Set Up Health Checks
Configure health checks to detect compromised instances. Unhealthy instances are replaced automatically.
5. Use Fly Proxy for TLS
Fly's proxy handles TLS termination. Ensure your app properly reads X-Forwarded-* headers.
6. Monitor with Fly Metrics
Use Fly's built-in metrics to detect unusual traffic patterns that might indicate attacks.
Common Security Mistakes
Avoid these common Fly.io security pitfalls:
Recommended Security Tools
Use these tools to maintain security throughout development:
Ready to Secure Your App?
Security is an ongoing process, not a one-time checklist. After implementing these steps, use VAS to verify your Fly.io app is secure before launch, and consider regular scans as you add new features.
Frequently Asked Questions
Are Fly secrets secure across regions?
Yes, Fly encrypts secrets and syncs them to all regions running your app. They're decrypted only when your app starts.
How do I secure internal services on Fly?
Use Fly's private networking with .internal domains. Internal services communicate over encrypted WireGuard tunnels without public exposure.