nodePort service bug sample

test.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: python-server-deployment
  labels:
    app: python-server
spec:
  replicas: 2
  selector:
    matchLabels:
      app: python-server
  template:
    metadata:
      namespace: demos
      labels:
        app: python-server
    spec:
      containers:
      - name: python-server
        image: python:3
        ports:
        - containerPort: 5060
          protocol: UDP
        command:
        - /bin/sh
        - -c
        - |
          export  PYTHONUNBUFFERED=true
          cat <<EOF >> server.py
          import socket
          sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
          server_address = '0.0.0.0'
          server_port = 5060

          server = (server_address, server_port)
          sock.bind(server)
          print("Listening on " + server_address + ":" + str(server_port))

          while True:
            payload, client_address = sock.recvfrom(4096)
            print("Echoing data back to " + str(client_address) + ": " + str(payload))
            sent = sock.sendto(payload, client_address)
          
          EOF
          python server.py
---
kind: Service
apiVersion: v1
metadata:
  name: python-server-service
  labels:
    app: python-server
spec:
  type: NodePort
  selector:
    app: python-server
  ports:
  - port: 5060
    name: python-server
    protocol: UDP
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: python-client-deployment
  labels:
    app: python-client
spec:
  replicas: 1
  selector:
    matchLabels:
      app: python-client
  template:
    metadata:
      namespace: demos
      labels:
        app: python-client
    spec:
      containers:
      - name: python-client
        image: python:3
        ports:
        - containerPort: 5060
          protocol: UDP
        command:
        - /bin/sh
        - -c
        - |
            export  PYTHONUNBUFFERED=true
            cat <<EOF >> client.py
            import socket
            import time
            sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
            server_address = '0.0.0.0'
            server_port = 5060
            target_port = 5060
            target_service = "python-server-service"          

            server = (server_address, server_port)
            sock.bind(server)
            print("Listening on " + server_address + ":" + str(server_port))

            index = 0 

            while True:
                serverip = socket.gethostbyname_ex(target_service)
                message = "" + str(index)
                index = index + 1
                print("Sending " + message + " to " + repr(serverip))
                sock.sendto(message.encode(), (target_service,target_port))
                sock.settimeout(5.0)
                try:
                    payload, client_address = sock.recvfrom(4096)
                    print("Server replied: " +  str(payload))
                except:
                    print("error")
                time.sleep(1)
            EOF
            python client.py