apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: restrict-pod-host-access
  annotations:
    policies.kyverno.io/title: Restrict host namespaces and hostPath (audit)
    policies.kyverno.io/category: Pod Security
    policies.kyverno.io/severity: medium
    policies.kyverno.io/description: >-
      Audit Pod Security restricted host access (hostNetwork, hostPID, hostIPC,
      hostPath). Complements deny-privileged; named exceptions for host agents.
spec:
  validationFailureAction: Audit
  background: true
  rules:
    - name: deny-host-namespaces
      match:
        any:
          - resources:
              kinds:
                - Pod
      exclude:
        any:
          - resources:
              namespaces:
                - kube-system
                - kube-public
                - kube-node-lease
                - flux-system
                - flux-canary
                - kyverno
                - cert-manager
                - cilium-secrets
                - olm
                - operators
                - longhorn
                - openebs
                - intel-system
                - nfd
      validate:
        message: >-
          Pods must not set hostNetwork, hostPID, or hostIPC (PSS restricted).
        pattern:
          spec:
            =(hostNetwork): "false"
            =(hostPID): "false"
            =(hostIPC): "false"
    - name: deny-hostpath-volumes
      match:
        any:
          - resources:
              kinds:
                - Pod
      exclude:
        any:
          - resources:
              namespaces:
                - kube-system
                - kube-public
                - kube-node-lease
                - flux-system
                - flux-canary
                - kyverno
                - cert-manager
                - cilium-secrets
                - olm
                - operators
                - longhorn
                - openebs
                - intel-system
                - nfd
      validate:
        message: >-
          Pods must not use hostPath volumes (PSS restricted). Prefer emptyDir,
          PVC, or projected volumes.
        pattern:
          spec:
            =(volumes):
              - X(hostPath): "null"