apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: math-exercises-netpol
spec:
  podSelector:
    matchLabels:
      app: math-exercises
  policyTypes:
  - Ingress
  - Egress
  ingress:
  # Allow inbound traffic from the ingress controller only
  - from:
    - namespaceSelector:
        matchLabels:
          name: ingress-nginx
    ports:
    - protocol: TCP
      port: 8000
  egress:
  # Allow outbound DNS resolution
  - to:
    - namespaceSelector:
        matchLabels:
          name: kube-system
    ports:
    - protocol: TCP
      port: 53
    - protocol: UDP
      port: 53
  # Allow outbound HTTPS for package updates or external APIs
  - ports:
    - protocol: TCP
      port: 443