Using Custom Classes to split Internal/External traffic

Kong Ingress Controller automatically creates a kong IngressClass when installed. All of the example ingress definitions in the documentation set spec.ingressClassName: kong, which allows things to work by default.

Advanced users of Kong Ingress Controller may wish to split traffic in to internal and external ingress definitions. This requires multiple Kong Ingress Controller instances, each pointing to a different IngressClass

Understanding IngressClass

The IngressClass resource binds an Ingress definition to an ingress controller. The value in the spec.controller field defines which ingress controller will process those ingress definitions. Kong Ingress Controller processes any IngressClass where spec.controller is set to ingress-controllers.konghq.com/kong.

Installing Kong

Kong Ingress Controller processes one IngressClass per installation. Kong Ingress Controller requires two deployments to split internal and external traffic.

Each deployment lives in its namespace, and the controller.ingressController.ingressClass value is set depending on whether that deployment should handle internal or external traffic.

helm upgrade --install kong-internal kong/ingress -n internal --create-namespace --set controller.ingressController.ingressClass=internal
helm upgrade --install kong-external kong/ingress -n external --create-namespace --set controller.ingressController.ingressClass=external

Creating Routes

Rather than setting spec.ingressClassName: kong in your Ingress definitions, you should now use either internal or external. Ingress definitions that target internal will only be available via Kong Gateway running in the internal namespace. Definitions that target external will only be available via the external gateway.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: echo-internal
  annotations:
    konghq.com/strip-path: "true"
spec:
  # This line controls if it's available internally or externally
  ingressClassName: internal 
  rules:
    - http:
        paths:
          - path: /echo
            pathType: ImplementationSpecific
            backend:
              service:
                name: echo
                port:
                  number: 1027