Engineering Log: Hardening ImgDuck — From Port Shielding to Fail-Closed AI Moderation and SaaS Architecture
A follow-up to our architectural notes on Zero-Trust Reverse Proxying & Sensitive Port Shielding. 1. Architectural Recap: The Shielded Port Foundation In our initial hardening deployment, we established our core security boundary: Strict Loopback Isolation. Public clients are strictly forbidden from establishing direct handshakes with application daemon ports. All microservices—including the storage backend (127.0.0.1:3000), the