Module shadow 

Traffic mirroring / shadowing for safe canary testing

This module implements fire-and-forget request duplication to shadow upstreams, enabling safe canary deployments and testing with production traffic.

Features

• Sampling-based mirroring (percentage control)
• Header-based sampling (selective mirroring)
• Optional request body buffering
• Fire-and-forget async execution (no blocking)
• Comprehensive metrics

Structs

ShadowManager

Manager for traffic shadowing/mirroring

Functions

buffer_request_body

Buffer request body from session with size limits

clone_body_for_shadow

Clone request body bytes for shadow traffic

should_buffer_method

Helper to determine if HTTP method should have body buffered