I have a simple Node.js chat example which uses socket.io. I have tested this deployment with a docker container locally, and a web client succesfully connects to the websocket (socket.io). The problem arise when I try to deploy this on a Kubernetes cluster with an ingress Controller.

My question is, is there anything special socket.io specifically needs when using an ingress controller?

The error message I get is <<browser name>> Can't estabilish a connection to the server at ws://<<address>>/socket.io/EIO=3&transport=websocket

Below is the simple implementation of the server side

var io = socket(server);
io.on('connection', (socket)=>{
    console.log('made socket connection')
    socket.on('chat', (message)=>{
        message:message.value
    })

Below is the client:

var socket = io.connect("http://localhost:3002", {
    upgrade: false,
    transports: ['websocket'],
    secure: True
});

My ingress yaml file looks like this

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ws-ingress
  namespace: websocket-ns
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/rewrite-target: /
    nginx.ingress.kubernetes.io/websocket-services: "ws-service"
    nginx.ingress.kubernetes.io/proxy-read-timeout: '3600'
    nginx.ingress.kubernetes.io/proxy-send-timeout: '3600'
    nginx.ingress.kubernetes.io/server-snippet: |
      http {
        server {
            listen 3002;
          location = / {
              proxy_set_header Upgrade "websocket";
              proxy_http_version 1.1;
              proxy_set_header X-Forwarded-Host $http_host;
              proxy_set_header X-Forwarded-Proto $scheme;
              proxy_set_header X-Forwarded-For $remote_addr;
              proxy_set_header Host $host;
              proxy_set_header Connection "upgrade";
              proxy_cache_bypass $http_upgrade;
            }
          upstream nodes {
              hash $remote_addr consistent;
              server app01:3002;
            }
      }
spec:
  rules:
    - host: "$host_address"
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: ws-service
                port:
                  number: 80

Service yaml:

apiVersion: v1
kind: Service
metadata:
  name: ws-service
  namespace: websocket-ns
  labels:
    app: ws-service
spec:
  type: LoadBalancer
  selector:
    app: ws-app
  ports:
    - port: 80
      protocol: TCP
      targetPort: 3002

Server deployment file:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: ws-app
  namespace: websocket-ns
  labels:
    app: ws-app
spec:
  replicas: 1
  selector:
    matchLabels:
      app: ws-app
  template:
    metadata:
      labels:
        app: ws-app
    spec:
      containers:
        - name: ws-app
          image: themuchy/socketexample
          ports:
            - containerPort: 3002
              name: ws-app