Deploying a Web Socket Application on Kubernetes

What is a WebSocket

WebSocket is a computer communications protocol, providing a simultaneous two-way communication channel over a single Transmission Control Protocol (TCP) connection. [Wikipedia]

Deploying a WebSocket application on Kubernetes can seem daunting, but this guide will simplify the process for you.

Prerequisites

1. A running kubernetes cluster.
2. A WebSocket app to be deployed.
3. Docker to containerize that application.

You can get a sample websocket app from this github repo adilansari488/websocket-sample-app.

Now let's create kubernetes manifest files.

Manifest files

Deployment.yaml

apiVersion: apps/v1 kind: Deployment metadata: name: ws-app-deployment namespace: default labels: app: ws-app spec: replicas: 1 selector: matchLabels: app: ws-app template: metadata: labels: app: ws-app spec: containers: - name: ws-app image: ws-app:latest imagePullPolicy: Always securityContext: privileged: true ports: - containerPort: 8819 resources: limits: cpu: 1000m memory: 1000Mi requests: cpu: 100m memory: 100Mi 

Service.yaml

apiVersion: v1 kind: Service metadata: name: ws-app namespace: dev spec: selector: app: ws-app ports: - name: ws-app port: 8819 targetPort: 8819 

In above manifest files, I have declared port no. 8819 for my websocket app but it can be any port on which your app will run.

Deploying to kubernetes

• Now build a docker image of your application or use this repository or directly use this docker image adilansari488/websocket-app to test.
• Now apply deployment.yaml and service.yaml to your k8s cluster and get the IP of your service.

• Now update the service ip in your client.py and test the connection.

Conclusion

Congratulations! You’ve successfully deployed your first websocket application. If you found this helpful, please like, share, and follow Adil Ansari for more valuable content.