Change:
<ins> --- title: Gateway API content_type: concept description: >- Gateway API is a family of API kinds that provide dynamic infrastructure provisioning and advanced traffic routing. weight: 55 --- <!-- overview --> Make network services available by using an extensible, role-oriented, protocol-aware configuration mechanism. [Gateway API](https://gateway-api.sigs.k8s.io/) is an {{<glossary_tooltip text="add-on" term_id="addons">}} containing API [kinds](https://gateway-api.sigs.k8s.io/references/spec/) that provide dynamic infrastructure provisioning and advanced traffic routing. <!-- body --> ## Design principles The following principles shaped the design and architecture of Gateway API: * __Role-oriented:__ Gateway API kinds are modeled after organizational roles that are responsible for managing Kubernetes service networking: * __Infrastructure Provider:__ Manages infrastructure that allows multiple isolated clusters to serve multiple tenants, e.g. a cloud provider. * __Cluster Operator:__ Manages clusters and is typically concerned with policies, network access, application permissions, etc. * __Application Developer:__ Manages an application running in a cluster and is typically concerned with application-level configuration and [Service](/docs/concepts/services-networking/service/) composition. * __Portable:__ Gateway API specifications are defined as [custom resources](docs/concepts/extend-kubernetes/api-extension/custom-resources) and are supported by many [implementations](https://gateway-api.sigs.k8s.io/implementations/). * __Expressive:__ Gateway API kinds support functionality for common traffic routing use cases such as header-based matching, traffic weighting, and others that were only possible in [Ingress](/docs/concepts/services-networking/ingress/) by using custom annotations. * __Extensible:__ Gateway allows for custom resources to be linked at various layers of the API. This makes granular customization possible at the appropriate places within the API structure. ## Resource model Gateway API has three stable API kinds: * __GatewayClass:__ Defines a set of gateways with common configuration and managed by a controller that implements the class. * __Gateway:__ Defines an instance of traffic handling infrastructure, such as cloud load balancer. * __HTTPRoute:__ Defines HTTP-specific rules for mapping traffic from a Gateway listener to a representation of backend network endpoints. These endpoints are often represented as a {{<glossary_tooltip text="Service" term_id="service">}}. Gateway API is organized into different API kinds that have interdependent relationships to support the role-oriented nature of organizations. A Gateway object is associated with exactly one GatewayClass; the GatewayClass describes the gateway controller responsible for managing Gateways of this class. One or more route kinds such as HTTPRoute, are then associated to Gateways. A Gateway can filter the routes that may be attached to its `listeners`, forming a bidirectional trust model with routes. The following figure illustrates the relationships of the three stable Gateway API kinds: {{< figure src="/docs/images/gateway-kind-relationships.svg" alt="A figure illustrating the relationships of the three stable Gateway API kinds" class="diagram-medium" >}} ### GatewayClass {#api-kind-gateway-class} Gateways can be implemented by different controllers, often with different configurations. A Gateway must reference a GatewayClass that contains the name of the controller that implements the class. A minimal GatewayClass example: ```yaml apiVersion: gateway.networking.k8s.io/v1 kind: GatewayClass metadata: name: example-class spec: controllerName: example.com/gateway-controller ``` In this example, a controller that has implemented Gateway API is configured to manage GatewayClasses with the controller name `example.com/gateway-controller`. Gateways of this class will be managed by the implementation's controller. See the [GatewayClass](https://gateway-api.sigs.k8s.io/references/spec/#gateway.networking.k8s.io/v1.GatewayClass) reference for a full definition of this API kind. ### Gateway {#api-kind-gateway} A Gateway describes an instance of traffic handling infrastructure. It defines a network endpoint that can be used for processing traffic, i.e. filtering, balancing, splitting, etc. for backends such as a Service. For example, a Gateway may represent a cloud load balancer or an in-cluster proxy server that is configured to accept HTTP traffic. A minimal Gateway resource example: ```yaml apiVersion: gateway.networking.k8s.io/v1 kind: Gateway metadata: name: example-gateway spec: gatewayClassName: example-class listeners: - name: http protocol: HTTP port: 80 ``` In this example, an instance of traffic handling infrastructure is programmed to listen for HTTP traffic on port 80. Since the `addresses` field is unspecified, an address or hostname is assigned to the Gateway by the implementation's controller. This address is used as a network endpoint for processing traffic of backend network endpoints defined in routes. See the [Gateway](https://gateway-api.sigs.k8s.io/references/spec/#gateway.networking.k8s.io/v1.Gateway) reference for a full definition of this API kind. ### HTTPRoute {#api-kind-httproute} The HTTPRoute kind specifies routing behavior of HTTP requests from a Gateway listener to backend network endpoints. For a Service backend, an implementation may represent the backend network endpoint as a Service IP or the backing Endpoints of the Service. An HTTPRoute represents configuration that is applied to the underlying Gateway implementation. For example, defining a new HTTPRoute may result in configuring additional traffic routes in a cloud load balancer or in-cluster proxy server. A minimal HTTPRoute example: ```yaml apiVersion: gateway.networking.k8s.io/v1 kind: HTTPRoute metadata: name: example-httproute spec: parentRefs: - name: example-gateway hostnames: - "www.example.com" rules: - matches: - path: type: PathPrefix value: /login backendRefs: - name: example-svc port: 8080 ``` In this example, HTTP traffic from Gateway `example-gateway` with the Host: header set to `www.example.com` and the request path specified as `/login` will be routed to Service `example-svc` on port `8080`. See the [HTTPRoute](https://gateway-api.sigs.k8s.io/references/spec/#gateway.networking.k8s.io/v1.HTTPRoute) reference for a full definition of this API kind. ## Request flow Here is a simple example of HTTP traffic being routed to a Service by using a Gateway and an HTTPRoute: {{< figure src="/docs/images/gateway-request-flow.svg" alt="A diagram that provides an example of HTTP traffic being routed to a Service by using a Gateway and an HTTPRoute" class="diagram-medium" >}} In this example, the request flow for a Gateway implemented as a reverse proxy is: 1. The client starts to prepare an HTTP request for the URL `http://www.example.com` 2. The client's DNS resolver queries for the destination name and learns a mapping to one or more IP addresses associated with the Gateway. 3. The client sends a request to the Gateway IP address; the reverse proxy receives the HTTP request and uses the Host: header to match a configuration that was derived from the Gateway and attached HTTPRoute. 4. Optionally, the reverse proxy can perform request header and/or path matching based on match rules of the HTTPRoute. 5. Optionally, the reverse proxy can modify the request; for example, to add or emove headers, based on filter rules of the HTTPRoute. 6. Lastly, the reverse proxy forwards the request to one or more backends. ## Conformance Gateway API covers a broad set of features and is widely implemented. This combination requires clear conformance definitions and tests to ensure that the API provides a consistent experience wherever it is used. See the [conformance](https://gateway-api.sigs.k8s.io/concepts/conformance/) documentation to understand details such as release channels, support levels, and running conformance tests. ## Migrating from Ingress Gateway API is the successor to the [Ingress](/docs/concepts/services-networking/ingress/) API. However, it does not include the Ingress kind. As a result, a one-time conversion from your existing Ingress resources to Gateway API resources is necessary. Refer to the [ingress migration](https://gateway-api.sigs.k8s.io/guides/migrating-from-ingress/#migrating-from-ingress) guide for details on migrating Ingress resources to Gateway API resources. ## {{% heading "whatsnext" %}} Instead of Gateway API resources being natively implemented by Kubernetes, the specifications are defined as [Custom Resources](docs/concepts/extend-kubernetes/api-extension/custom-resources) supported by a wide range of [implementations](https://gateway-api.sigs.k8s.io/implementations/). [Install](https://gateway-api.sigs.k8s.io/guides/#installing-gateway-api) the Gateway API CRDs or follow the installation instructions of your selected implementation. After installing an implementation, use the [Getting Started](https://gateway-api.sigs.k8s.io/guides/) guide to help you quickly start working with Gateway API. {{< note >}} Make sure to review the documentation of your selected implementation to understand any caveats. {{< /note >}} Refer to the [API specification](https://gateway-api.sigs.k8s.io/reference/spec/) for additional details of all Gateway API kinds. </ins>

Discussion:
This is a Feature Request What would you like to be High level documentation for Gateway API with links out to https://gateway- This should include the following: new "Gateway API" page between Service and Ingress in This should provide a high level overview of Gateway API, with a focus on content that is unlikely to become stale. This can likely take some content from both https://gateway- and https://gateway- and would help increase the discoverability of Gateway API. the "Ingress" page to note that the API is effectively frozen and all new features are being to Gateway API (with a corresponding link to the page by 1). the section on the "Service" page that references Ingress and Gateway API to give more prominence to Gateway API. Why is this needed With the upcoming graduation of Gateway API to GA (x-ref ), it's past time to cover it in Kubernetes docs. Comments I'd previously talked with about this at a high level, but definitely let me know if you've got any suggestions for how we can scope/adjust this differently. /sig network /assign
checkout the gateway API in the section and look out for the bugs
/triage accepted /priority important-longterm
How about adding a short link eg that redirects (302) to https://gateway- ?
I'd put Service, Ingress, then Gateway - and leave it in that order until most new clusters include Gateway as an add-on.
Also see