Modern Traffic Management with Gateway API in Kubernetes

This talk introduces the Gateway API as a modern alternative to the traditional Kubernetes Ingress for managing traffic within clusters. The current Ingress model suffers from several limitations: it relies heavily on annotations for advanced features, behaves inconsistently across different controllers, supports only basic HTTP routing (host/path), and lacks key functionalities such as delegation, multi-port support, and proper diagnostics or status reporting.

The Gateway API, initiated at KubeCon 2019, addresses these issues with a more expressive, extensible, and role-oriented design. Its architecture introduces key components like GatewayClass, Gateway, and various types of Routes (e.g., HTTPRoute, GRPCRoute, TCPRoute), as well as ReferenceGrant for cross-namespace routing. It separates responsibilities clearly between platform providers, cluster administrators, and developers.

Version 1.2.1 of the Gateway API offers a wide range of features: advanced request matching (by path, header, method, query params), traffic splitting, retries, timeouts, WebSocket support, TLS passthrough, header manipulation, redirects, URL rewrites, and extension points for custom behavior. It also includes support for service mesh scenarios through GAMMA (Gateway API for Mesh Management and Administration).

The API is gaining strong adoption, with General Availability (GA) support from major platforms and vendors including AWS, Google Cloud, Azure, Kong, Istio, Traefik, and NGINX. Support is categorized into core (portable across all implementations), extended, and implementation-specific features.

In summary, the Gateway API offers a robust, flexible, and future-proof foundation for traffic management in Kubernetes, enabling better collaboration, more powerful routing logic, and improved observability compared to the legacy Ingress approach.

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