Kubernetes Load Balancer with multiple ports

November 22, 2018 4.3k views
Kubernetes Load Balancing

What is needed to create a kubernetes load balancer that supports multiple inbound ports? Is there an example of this anywhere?

EG

listening on port 9999 for silly-domain.com

listening on port 443 for standard-domain.com

3 Answers
vga99 December 1, 2018
Accepted Answer

I got the former one to work on my beta k8s cluster on DO.

Official link: https://github.com/kubernetes/ingress-nginx
And here is the configuration I used on my cluster: https://github.com/haugom/do-ingress-nginx/

mandatory.xml installs it while the loadbalancer sets up a DO loadbalancer which sends traffic to ingress-nginx.

The custom default backend and external dns are something I added later for fun.

/G.

Load balancers can listen to multiple ports, but they can only point at one backend service. You’ll need to put something like ingress-nginx behind the load balancer to route traffic for different domains to different services.

kind: Service
apiVersion: v1
metadata:
  name: ingress-nginx
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
spec:
  externalTrafficPolicy: Local
  type: LoadBalancer
  selector:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
  ports:
    - name: http
      port: 80
      targetPort: http
    - name: https
      port: 443
      targetPort: https

Just to add to the above answer, there are currently two implementations for an nginx ingress available, one from the Kubernetes community and one from NGINX, Inc. I couldn’t get the former to work, but the latter did work for me, as long as all the resources are within the same namespace.

I’ve contacted the DO support team and they confirmed this is indeed a requirement that will be documented at a later point.

You can deploy the ingress using the helm chart or through manual deployments: https://github.com/nginxinc/kubernetes-ingress

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