[ATLURI0001]

Overview

Hardens proxy snippet invariants with upstream failover policies, uniform read/send timeouts, runtime header stripping (X-Powered-By), and end-to-end request trace ID (X-Request-ID) propagation through demo backend services.

Technical Highlights

• Upstream Failover & Retries: Added proxy_next_upstream error timeout http_502 http_503 http_504; with proxy_next_upstream_tries 2; in nginx/snippets/proxy.conf to enable transparent fallback across pool members (e.g. api-a to api-b).
• Read Timeout Alignment: Explicitly declared proxy_read_timeout 30s; alongside proxy_send_timeout 30s; and proxy_connect_timeout 3s;.
• Runtime Fingerprint Mitigation: Added proxy_hide_header X-Powered-By; to prevent leaking backend framework versions to clients.
• Trace ID Propagation: In apps/demo/app.py, extracted incoming X-Request-ID and forwarded it in both response headers and JSON/HTML payloads across /health and wildcard index routes.

Quality Assurance

• Executed unit test suite via python -m unittest discover tests:
  • Verified proxy forwarding invariants including failover, timeout alignment, and header stripping.
  • Added test_trace_id_propagation_in_demo_app asserting header extraction and response payload inclusion.
  • Ran 17 tests with 0 failures in 0.002s.