apiVersion: v1
kind: ConfigMap
metadata:
  name: python-script
data:
  entrypoint.py: |
    import os
    from http.server import BaseHTTPRequestHandler, HTTPServer

    class PodNameHandler(BaseHTTPRequestHandler):
        def do_GET(self):
            pod_name = os.environ.get('POD_NAME', 'unknown-pod')
            self.send_response(200)
            self.send_header('Content-Type', 'text/plain; charset=utf-8')
            self.end_headers()
            self.wfile.write(f"Pod name: {pod_name}\n".encode('utf-8'))

    def run(server_class=HTTPServer, handler_class=PodNameHandler, port=8080):
        server_address = ('', port)
        httpd = server_class(server_address, handler_class)
        print(f"Starting server on port {port}, serving Pod name...")
        httpd.serve_forever()

    if __name__ == '__main__':
        run()

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: python-deployment
  labels:
    app: python
spec:
  replicas: 3
  selector:
    matchLabels:
      app: python
  template:
    metadata:
      labels:
        app: python
    spec:
      affinity:
        podAntiAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            - labelSelector:
                matchExpressions:
                  - key: app
                    operator: In
                    values:
                      - python
              topologyKey: topology.kubernetes.io/zone
      containers:
        - name: python
          image: python:3.13.5-alpine
          command: ["python", "/app/entrypoint.py"]
          ports:
            - containerPort: 8080
          env:
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
          volumeMounts:
            - name: python-script
              mountPath: /app
      volumes:
        - name: python-script
          configMap:
            name: python-script
---
apiVersion: v1
kind: Service
metadata:
  name: python-service
spec:
  trafficDistribution: PreferClose
  selector:
    app: python
  ports:
    - protocol: TCP
      port: 8080
      targetPort: 8080
  type: ClusterIP