Cybrove
Hosting/Cloud Security

Is Fly.io Secure? Security Features, Risks, and Hardening

Yes, Fly.io is generally secure when configured correctly. Here is what you need to know about its built-in protections, common vulnerabilities, and how to harden it for production.

Built-in Security Features

Firecracker microVM isolation for each application
Automatic TLS termination at edge locations
Private IPv6 networking between apps in the same organization
Encrypted volumes for persistent storage
WireGuard VPN for secure access to internal services

Common Vulnerabilities

Exposed internal services through misconfigured fly.toml services
Secrets management missteps with fly secrets
Unencrypted inter-region traffic without WireGuard
Missing health check authentication on management endpoints

Hardening Checklist

1Use fly secrets for all sensitive configuration values
2Configure internal_port and restrict services to private networking
3Use WireGuard VPN for all administrative access
4Implement fly.toml [[services]] with strict port and protocol settings
5Enable connection encryption for Fly Postgres instances
6Configure auto-scaling limits to prevent resource exhaustion
7Use Fly organizations for team access control
8Set up metrics and monitoring for anomaly detection

Read the complete Fly.io security guide

In-depth blog post with code examples and best practices

Official Fly.io security documentation

Frequently Asked Questions

Is Fly.io secure?

Yes, Fly.io is generally secure when configured correctly. It includes built-in protections like firecracker microvm isolation for each application. However, common misconfigurations and development patterns can introduce vulnerabilities.

What are the main security risks with Fly.io?

The most common Fly.io security risks include exposed internal services through misconfigured fly.toml services, secrets management missteps with fly secrets, unencrypted inter-region traffic without wireguard.

How do I harden Fly.io for production?

Key hardening steps: Use fly secrets for all sensitive configuration values. Configure internal_port and restrict services to private networking. Use WireGuard VPN for all administrative access. Run a security check on your domain to identify specific issues.

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