Azure Kubernetes loadbalancer with Ingress and path based routing

Question

I am trying to create a basic path based routing ingress controller with an AKS managed Load Balancer. Trouble is figuring out how to route from the Load Balancer to the Ingress controller.

Here is my ingress controller yml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-cpr
  annotations:
    kubernetes.io/ingress.class: nginx  
spec:  
  rules:
  - http:
      paths:
      - path: /green/
        pathType: Prefix
        backend:
          service: 
            name: nginx-green-clusterip-service
            port: 
              number: 80
      - path: /red/
        pathType: Prefix
        backend:
          service: 
            name: nginx-red-clusterip-service
            port: 
              number: 80

As you can see, the ingress controller is responsible to send to the appropriate app based on the incoming path.

But how do I get this connected to a managed Load Balancer?

apiVersion: v1
kind: Service
metadata:
  name: loadbal-service
spec:
  type: LoadBalancer
  ports:
  - port: 80
  selector:
    app: ingress-cpr

I know this line isnt correct "-app: ingress-cpr". But what do I have to do so that the LoadBalancer forwards to the ingress controller?

Thanks in advance, Jake.

Answer 1

In the service manifest the app's selector should be pointing to the backend service name of the ingress. In this particular case instead of ingress-cpr in the service manifest should be either of the two backends (nginx-green-clusterip-service or nginx-red-clusterip-service). Any traffic via external IP of the managed LB on port 80 should be routed to one of the backend defined in the ingress then.

There is also Microsoft example about creation of basic ingress controller in AKS.