API Gateway Patterns: Kong, Envoy, and Traefik

The article explains the role of an API gateway as a single entry point that centralises authentication, rate limiting, routing, load balancing, caching, and observability for backend services. It compares three popular gateways—Kong, Envoy, and Traefik—highlighting Kong’s evolution from an Nginx‑based gateway to a full‑featured API management platform. The author provides a Docker‑Compose example for Kong 3.8, showing how to spin up a Postgres database, configure environment variables, expose ports 8000/8001, and create services and routes via curl. It also demonstrates adding a rate‑limiting plugin and a JWT authentication plugin to Kong. For Envoy, the article supplies a YAML configuration that defines listeners, filter chains, HTTP connection managers, virtual hosts, routes, retry policies, and clusters pointing to user‑service and order‑service. The guide emphasises that using an API gateway eliminates duplicated auth and rate‑limiting logic in each microservice. It also notes that Envoy is the data plane for Istio and other service meshes, offering high performance and programmability. The article concludes by encouraging developers to set up either Kong or Envoy to centralise cross‑cutting concerns and improve observability.