Envoy

Prerequisite: Read Part 3 — Composable E-Commerce Migration to understand domain bounded context mapping. Zero-Downtime Blueprint: Moving from Magento to Microservices via Strangler Fig Answer-first: Zero-downtime migration from a Magento monolith to Go microservices is executed via a 3-phase Strangler Fig pattern: Phase 1 (Interception) deploys Envoy Gateway 1.30+ to route live traffic and inject W3C traceparent headers; Phase 2 (Dual-Run & Shadowing) mirrors 100% of production traffic to newly extracted Go services while synchronizing state bidirectionally via Debezium 3.0+ CDC; and Phase 3 (Canary Cutover & Decommission) shifts traffic incrementally (1% -> 10% -> 100%) before retiring the PHP monolith after a 30-day hot-standby period. ...

Answer-first: API Gateways govern north-south ingress traffic crossing untrusted perimeter boundaries, executing edge authentication, rate limiting, and protocol translation. Conversely, Service Meshes manage east-west internal pod-to-pod communication, enforcing mutual TLS zero-trust identity, distributed telemetry, and traffic shifting. Rather than competing alternatives, modern architectures deploy both symbiotically, with eBPF sockops bypassing kernel TCP stacks to eliminate sidecar proxy latency. Prerequisite: In-depth knowledge of OSI Layer 4/Layer 7 networking, Kubernetes Ingress and Gateway API specifications, Envoy proxy architecture, and mutual TLS fundamentals is required for this chapter. ...