apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: deny-customer-pod
  namespace: wsi
spec:
  podSelector:
    matchLabels:
      app: customer
  policyTypes:
  - Ingress
  ingress:
  - from:
    - podSelector:
        matchLabels:
          app: product

kubectl apply -f customer.yaml

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: deny-product-pod
  namespace: wsi
spec:
  podSelector:
    matchLabels:
      app: product
  policyTypes:
  - Ingress
  ingress:
  - from:
    - podSelector:
        matchLabels:
          app: customer

kubectl apply -f product.yaml