Disallow hostPorts

apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: disallow-host-ports
  annotations:
    policies.kyverno.io/title: Disallow hostPorts
    policies.kyverno.io/category: Pod Security Standards (Baseline)
    policies.kyverno.io/severity: medium
    policies.kyverno.io/subject: Pod
    kyverno.io/kyverno-version: 1.6.0
    kyverno.io/kubernetes-version: 1.22-1.23
    policies.kyverno.io/description: "Access to host ports allows potential snooping of network traffic and should not be allowed, or at minimum restricted to a known list. This policy ensures the `hostPort` field is unset or set to `0`. "
spec:
  validationFailureAction: Audit
  background: true
  rules:
    - name: host-ports-none
      match:
        any:
          - resources:
              kinds:
                - Pod
      validate:
        message: Use of host ports is disallowed. The fields spec.containers[*].ports[*].hostPort , spec.initContainers[*].ports[*].hostPort, and spec.ephemeralContainers[*].ports[*].hostPort must either be unset or set to `0`.
        pattern:
          spec:
            "=(ephemeralContainers)":
              - "=(ports)":
                  - "=(hostPort)": 0
            "=(initContainers)":
              - "=(ports)":
                  - "=(hostPort)": 0
            containers:
              - "=(ports)":
                  - "=(hostPort)": 0