<p>I have an app with a React frontend and Flask backend that I can run successfully both locally and in Docker, and I'm now trying to deploy it to Kubernetes. The Flask part works fine, but when I try to access the React service and it sends requests back to the Flask service, I get an AxiosEror saying &quot;timeout of 300000ms exceeded&quot;.</p>
<p>The YAML specs for the React deployment look like this:</p>
<pre><code>apiVersion: apps/v1
kind: Deployment
metadata:
  name: react-deployment
  labels:
    app: react
spec:
  replicas: 3
  selector:
    matchLabels:
      app: react
  template:
    metadata:
      labels:
        app: react
    spec:
      containers:
      - name: react-app
        image: host.docker.internal:5002/react-app:latest
        env:
        - name: REACT_APP_BACKEND_HOST
          value: http://flask-service.default.svc.cluster.local:5000
        ports:
        - containerPort: 3000
      imagePullSecrets:
      - name: hello-world-cred
</code></pre>
<p>Where REACT_APP_BACKEND_HOST is the URL that the React deployment sends requests to.</p>
<p>I've checked the YAML file and I've confirmed that the URL for the requests is the correct one to access the backend from within the K8s cluster. I SSHed into one of the pods for the React deployment and curled the URL to make sure, and it responded normally. I can't figure out why it's not responding when the requests are sent by the React deployment.</p>

Avi Kraft
<p>The error is resolved. I set up a reverse proxy server using NGINX to route my requests and deployed it to K8s along with the other layers. The app is working as intended now.</p>
