apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
  name: kube-system-restrict-external-egress
  namespace: kube-system
spec:
  endpointSelector: {}

  egress:
    # Allow Kubernetes API
    - toEntities:
        - kube-apiserver

    # Allow internal cluster communication
    - toEntities:
        - cluster
        - host
        - remote-node

    # Allow DNS
    - toEndpoints:
        - matchLabels:
            k8s:k8s-app: kube-dns
      toPorts:
        - ports:
            - port: "53"
              protocol: UDP
            - port: "53"
              protocol: TCP