apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: deny-customer-pod
  namespace: skills
spec:
  podSelector:
    matchLabels:
      app: customer
  policyTypes:
  - Ingress
  - Egress
  ingress:
  - from:
    - podSelector:
        matchLabels:
          app: product
    - podSelector:
        matchLabels:
          app: order
  egress:
    - to:
        - ipBlock:
            cidr: 0.0.0.0/0
      ports:
        - port: 443
        - port: 80
        - port: 53
          protocol: TCP
        - port: 53
          protocol: UDP

kubectl apply -f customer.yaml

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: deny-product-pod
  namespace: skills
spec:
  podSelector:
    matchLabels:
      app: product
  policyTypes:
  - Ingress
  - Egress
  ingress:
  - from:
    - podSelector:
        matchLabels:
          app: customer
    - podSelector:
        matchLabels:
          app: order
  egress:
    - to:
        - ipBlock:
            cidr: 0.0.0.0/0
      ports:
        - port: 443
        - port: 80
        - port: 53
          protocol: TCP
        - port: 53
          protocol: UDP

kubectl apply -f product.yaml

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: deny-order-pod
  namespace: skills
spec:
  podSelector:
    matchLabels:
      app: order
  policyTypes:
  - Ingress
  - Egress
  ingress:
  - from:
    - podSelector:
        matchLabels:
          app: customer
    - podSelector:
        matchLabels:
          app: product
  egress:
    - to:
        - ipBlock:
            cidr: 0.0.0.0/0
      ports:
        - port: 443
        - port: 80
        - port: 53
          protocol: TCP
        - port: 53
          protocol: UDP

kubectl apply -f order.yaml