Disallow hostPorts Range (Alternate)

 1apiVersion: kyverno.io/v1
 2kind: ClusterPolicy
 3metadata:
 4  name: disallow-host-ports-range
 5  annotations:
 6    policies.kyverno.io/title: Disallow hostPorts Range (Alternate)
 7    policies.kyverno.io/category: Pod Security Standards (Baseline)
 8    policies.kyverno.io/severity: medium
 9    policies.kyverno.io/subject: Pod
10    kyverno.io/kyverno-version: 1.6.0
11    policies.kyverno.io/minversion: 1.6.0
12    kyverno.io/kubernetes-version: "1.22-1.23"
13    policies.kyverno.io/description: >-
14      Access to host ports allows potential snooping of network traffic and should not be
15      allowed by requiring host ports be undefined (recommended) or at minimum restricted to a known list.
16      This policy ensures the `hostPort` field, if defined, is set to either a port in the specified range
17      or to a value of zero. This policy is mutually exclusive of the disallow-host-ports policy.
18      Note that Kubernetes Pod Security Admission does not support the host port range rule.
19spec:
20  validationFailureAction: Audit
21  background: true
22  rules:
23    - name: host-port-range
24      match:
25        any:
26        - resources:
27            kinds:
28              - Pod
29      preconditions:
30        all:
31        - key: "{{ request.operation }}"
32          operator: NotEquals
33          value: DELETE
34      validate:
35        message: >-
36          The only permitted hostPorts are in the range 5000-6000 or 0.
37        deny:
38          conditions:
39            all:
40            - key: "{{ request.object.spec.[ephemeralContainers, initContainers, containers][].ports[].hostPort }}"
41              operator: AnyNotIn
42              value: 5000-6000
43            - key: "{{ request.object.spec.[ephemeralContainers, initContainers, containers][].ports[].hostPort }}"
44              operator: AnyNotIn
45              value:
46              - 0