Cannot connect websocket server in Kubernetes

Hello,

I’m trying to connect to my websocket server deployed in Kubernetes but I cannot do it. This is my configuration and what I tried so far.

Option 1: nodejs websocket server without ingress and nginx reverse proxy

ws server config

apiVersion: v1
kind: Service
metadata:
  name: ws-server
spec:
  ports:
  - port: 91
    targetPort: 80
    protocol: TCP
  selector:
    app: ws-server
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ws-server
  labels:
    app: ws-server
spec:
  replicas: 2 
  selector:
    matchLabels:
      app: ws-server
  template:
    metadata:
      labels:
        app: ws-server
    spec:
      containers:
      - name: ws-server
        image: MY_IMAGE
        ports:
        - containerPort: 91

ingress config

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: chameleon-ingress
spec:
  rules:
  - host: MY_HOST
    http:
      paths:
      - backend:
          serviceName: ws-server
          servicePort: 91

Docker file

FROM node:14.5.0-alpine3.10

WORKDIR /app

COPY . .

CMD ["node", "/app/src/index.js"]

Option 2: nodejs websocket server with ingress configuration

Same “ws server config” and Dockerfile

New ingress config

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: nginx

    nginx.org/websocket-services: ws-server
    nginx.ingress.kubernetes.io/websocket-services: ws-server
  name: chameleon-ingress
spec:
  rules:
  - host: MY_HOST
    http:
      paths:
      - backend:
          serviceName: ws-server
          servicePort: 91

Option 3: nginx as reverse proxy

Same ws server config and ingress config as option 1

Dockerfile

FROM nginx:1.19.0-alpine

WORKDIR /app

COPY . .
COPY nginx/MY_CONF.conf /etc/nginx/conf.d/default.conf
RUN apk add --update nodejs
CMD ["sh", "-c", "tail -f /dev/null"]

Note: I do the last command on purpose because I want to run the node src/index.js by myself to see the logs.

MY_CONF.conf

server {
  listen        80;
  server_name   localhost;

  location /ws {
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
   proxy_pass "http://localhost:3000";
  }

  error_page  404  /404.html;
   location = /40x.html{
   }
  error_page  500 502 503 504 /50x.html;
   location = /50x.html{
  } 
}

Note: I changed the ws server to listen in port 3000

The problem is that I can connect to option 1 and 3 on my local machine but when I deploy it connection cannot be established and nothing is shown in the logs. I haven’t set up a firewall yet, it’s the default config (all open) and other backend services with nginx or API REST are working but not the websockets.

Do you know what this could be?