Is Fly.io Safe?
Fly.io is safe with strong VM isolation using Firecracker technology. Global edge deployment and private networking provide excellent security. Application security remains your responsibility.
Firecracker Isolation
Fly.io uses Firecracker microVMs (developed by AWS) for hardware-level isolation. Each application runs in its own VM, providing stronger security boundaries than container-based platforms.
Security Considerations
Private Networking
Use Fly's private network for internal communication. Don't expose internal services publicly.
Volume Encryption
Enable volume encryption for persistent storage containing sensitive data. This is not enabled by default.
Secrets Management
Use Fly secrets for sensitive configuration. Secrets are encrypted and injected as environment variables.
Application Security
Fly secures infrastructure. Authentication, authorization, and input validation are your responsibility.
Security Assessment
Strengths
- + Hardware-level VM isolation (Firecracker)
- + Automatic HTTPS with managed certificates
- + Private networking between apps
- + Encrypted secrets management
- + Global anycast for DDoS resilience
- + SOC 2 Type II compliance
Concerns
- - Application security is developer responsibility
- - Database access needs proper configuration
- - Volume encryption is opt-in
- - Complex networking requires careful setup
The Verdict
Fly.io is a safe deployment platform with excellent infrastructure security. Firecracker VM isolation provides stronger boundaries than containers. Enable volume encryption for sensitive data and use private networking for internal services. Application-level security is your responsibility.
Related Resources
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