AKS pod websocket connection is breaking

Question

I am using AKS to run my pods and Azure Application Gateway as a web traffic load balancer. I have an issue with one of the pods using WebSocket, the WebSocket connection is breaking. The Application Gateway documentation states that Application Gateway provides native support for WebSocket, but the connection is not being maintained. I also tested this in App Service, where the connection does not break. What steps need to be implemented to maintain the connection in the AKS pod?

Answer 1

Hello Venkat Tharun D A,

Kubernetes deployment YAML shows the minimum configuration used to deploy a WebSocket server. After all the prerequisites are fulfilled, and you have an Application Gateway controlled by a Kubernetes Ingress in your AKS, the deployment shown would expose a WebSockets server on port 80 of your Application Gateway's public IP and the ws.contoso.com domain.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: websocket-server
spec:
  selector:
    matchLabels:
      app: ws-app
  replicas: 2
  template:
    metadata:
      labels:
        app: ws-app
    spec:
      containers:
        - name: websocket-app
          imagePullPolicy: Always
          image: your-container-repo.azurecr.io/websockets-app
          ports:
            - containerPort: 8888
      imagePullSecrets:
        - name: azure-container-registry-credentials
---
apiVersion: v1
kind: Service
metadata:
  name: websocket-app-service
spec:
  selector:
    app: ws-app
  ports:
  - protocol: TCP
    port: 80
    targetPort: 8888
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: websocket-repeater
  annotations:
    kubernetes.io/ingress.class: azure/application-gateway
spec:
  rules:
    - host: ws.contoso.com
      http:
        paths:
          - backend:
              serviceName: websocket-app-service
              servicePort: 80

please find the below documentation link for the same .

https://learn.microsoft.com/en-us/azure/application-gateway/ingress-controller-expose-websocket-server

Hope this helps you.