[FIXED] How can I proxy requests to an External Port in Kubernetes?

Issue

I have a web service running on a port on my local network exposed at port 6003. I also have a Kubernetes Cluster running on a different machine on the same network that uses and Nginx Ingress to proxy to all the services in the cluster. How can I set up an ingress to proxy to the machine? I had a set up that worked. But now, I am either getting DNS errors on the nginx pod or the response times out in the browser and nothing happens.

Here is the manifest I have been using.

apiVersion: v1
kind: Service
metadata:
  name: myservice-service
spec:
  type: ExternalName
  externalName: 192.xxx.xx.x
ports:
  - name: myservice
    port: 80
    protocol: TCP
    targetPort: 6003
---
apiVersion: v1
kind: Endpoints
metadata:
  name: myservice-ip
subsets:
  - addresses:
      # list all external ips for this service
      - ip: 192.xxx.xx.x
    ports:
      - name: myservice
        port: 6003
        protocol: TCP
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: service.example.com
  annotations:
    nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
spec:
  rules:
    - host: service.example.com
      http:
        paths:
          - backend:
              serviceName: myservice-service
              servicePort: 80
            path: /
  tls:
    - secretName: secret-prod-tls
      hosts:
        - service.example.com

Edit for more information: This manifest does work. What I realized is that you must specify https even though the ingress has a tls block. This still is showing Lua DNS errors in the Nginx-ingress pod though.

Solution

You MUST specify nginx.ingress.kubernetes.io/backend-protocol: "HTTPS" in your ingress resource if upstream listening for HTTPS requests. So, this is related to backend, not ingress itself. TLS configuration is for Ingress (frontend), and not for backend application.

Answered By - clxoid

Answer Checked By - Willingham (PHPFixing Volunteer)