netpol-allow-egress-to-database.yaml

---
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-egress-to-database
  namespace: backend
spec:
  podSelector:
    matchLabels: {}
  egress:
    - to:
      - podSelector:
          matchLabels: {}
        namespaceSelector:
           matchLabels:
              tier: database
    - to:
      - namespaceSelector:
          matchLabels:
            kubernetes.io/metadata.name: kube-system
        podSelector:
          matchLabels:
            k8s-app: kube-dns
      ports:
      - protocol: UDP
        port: 53
---