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

  ingress:
    # Allow cluster-internal communication (required for DNS, CNI, etc.)
    - fromEntities:
        - cluster
        - host
        - remote-node

    # Allow kube-apiserver to talk to system components
    - fromEntities:
        - kube-apiserver

  egress:
    # Core dependency: Kubernetes API
    - toEntities:
        - kube-apiserver

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

    # Allow internal cluster communication (important for CNI + service mesh)
    - toEntities:
        - cluster
        - host
        - remote-node