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Kubernetes Ingress Controller
2.2.x
You are browsing documentation for an outdated version. See the latest documentation here.

Using Gateway API

This feature is released as a tech preview (alpha-quality) and should not be deployed in a production environment.

Gateway API is a set of resources for configuring networking in Kubernetes. It expands on Ingress to configure additional types of routes (TCP, UDP, and TLS in addition to HTTP/HTTPS), support backends other than Service, and manage the proxies that implement routes.

Gateway API and Kong’s implementation of Gateway API are both in alpha stage and under active development. Features and implementation specifics will change before their initial general availability release.

Enable the feature

The Gateway API CRDs are not yet available by default in Kubernetes. You must first install them.

The default controller configuration disables Gateway API handling. To enable it, set ingressController.env.feature_gates: Gateway=true in your Helm values.yaml, or set CONTROLLER_FEATURE_GATES=Gateway=true if not using Helm. Note that you must restart Pods with this flag set after installing the Gateway API CRDs.

If using Helm, you must use chart version 2.7 or higher. Older versions do not include the ServiceAccount permissions necessary for KIC to read Gateway API resources.

Testing connectivity to Kong

This guide assumes that the PROXY_IP environment variable is set to contain the IP address or URL pointing to Kong. Follow one of the deployment guides to configure this environment variable.

If everything is set up correctly, making a request to Kong should return HTTP 404 Not Found.

Note: If you are running the example using Minikube on MacOS, you may need to run minikube tunnel in a separate terminal window. This exposes LoadBalancer services externally, which is not enabled by default.

$ curl -i $PROXY_IP
HTTP/1.1 404 Not Found
Content-Type: application/json; charset=utf-8
Connection: keep-alive
Content-Length: 48
Server: kong/1.2.1

{"message":"no Route matched with those values"}

This is expected, as Kong does not yet know how to proxy the request.

Set up an echo-server

Set up an echo-server application to demonstrate how to use the Kubernetes Ingress Controller:

$ kubectl apply -f https://bit.ly/echo-service

Add a GatewayClass and Gateway

The Gateway resource represents the proxy instance that handles traffic for a set of Gateway API routes, and a GatewayClass describes characteristics shared by all Gateways of a given type.

Add a GatewayClass:

$ echo "apiVersion: gateway.networking.k8s.io/v1alpha2
apiVersion: gateway.networking.k8s.io/v1alpha2
kind: GatewayClass
metadata:
  name: kong
spec:
  controllerName: konghq.com/kic-gateway-controller
" | kubectl apply -f -

gatewayclass.gateway.networking.k8s.io/kong created

Add a Gateway:

$ echo "apiVersion: gateway.networking.k8s.io/v1alpha2
kind: Gateway
metadata:
  annotations:
    konghq.com/gateway-unmanaged: kong/kong-proxy
  name: kong
spec:
  gatewayClassName: kong
  listeners:
  - name: proxy
    port: 80
    protocol: HTTP
  - name: proxy-ssl
    port: 443
    protocol: HTTPS
" | kubectl apply -f -

gateway.gateway.networking.k8s.io/kong created

Because KIC and Kong instances are installed independent of their Gateway resource, we set the konghq.com/gateway-unmanaged annotation to the <namespace>/<name> of the Kong proxy Service. This instructs KIC to populate that Gateway resource with listener and status information. You can check to confirm if KIC has updated the bound Gateway by inspecting the list of associated addresses:

$ kubectl get gateway kong -o=jsonpath='{.status.addresses}' | jq

[
  {
    "type": "IPAddress",
    "value": "10.96.179.122"
  },
  {
    "type": "IPAddress",
    "value": "10.96.179.122"
  },
  {
    "type": "IPAddress",
    "value": "172.18.0.240"
  }
]

Add an HTTPRoute

HTTPRoute resources are similar to Ingress resources: they contain a set of matching criteria for HTTP requests and upstream Services to route those requests to.

$ echo "apiVersion: gateway.networking.k8s.io/v1alpha2
kind: HTTPRoute
metadata:
  name: echo
spec:
  parentRefs:
  - group: gateway.networking.k8s.io
    kind: Gateway
    name: kong
  rules:
  - backendRefs:
    - group: ""
      kind: Service
      name: echo
      port: 80
      weight: 1
    matches:
    - path:
        type: PathPrefix
        value: /echo
" | kubectl apply -f -

After creating an HTTPRoute, accessing /echo forwards a request to the echo service:

$ curl -i $PROXY_IP/echo

HTTP/1.1 200 OK
Content-Type: text/plain; charset=UTF-8
Transfer-Encoding: chunked
Connection: keep-alive
Date: Fri, 21 Jun 2019 18:09:02 GMT
Server: echoserver
X-Kong-Upstream-Latency: 1
X-Kong-Proxy-Latency: 1
Via: kong/1.1.2



Hostname: echo-758859bbfb-cnfmx
...

Alpha limitations

The KIC Gateway API alpha is a work in progress, and not all features of Gateway APIs are supported. In particular:

  • HTTPRoute is the only supported route type. TCPRoute, UDPRoute, and TLSRoute are not yet implemented.
  • HTTPRoute does not yet support multiple backendRefs. You cannot distribute requests across multiple Services.
  • queryParam matches and RegularExpression path matches are not yet supported.