Restrict Volume Types

apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: restrict-volume-types
  annotations:
    policies.kyverno.io/title: Restrict Volume Types
    policies.kyverno.io/category: Pod Security Standards (Restricted)
    policies.kyverno.io/severity: medium
    policies.kyverno.io/subject: Pod,Volume
    policies.kyverno.io/minversion: 1.6.0
    kyverno.io/kubernetes-version: 1.22-1.23
    kyverno.io/kyverno-version: 1.6.0
    policies.kyverno.io/description: In addition to restricting HostPath volumes, the restricted pod security profile limits usage of non-core volume types to those defined through PersistentVolumes. This policy blocks any other type of volume other than those in the allow list.
spec:
  validationFailureAction: Audit
  background: true
  rules:
    - name: restricted-volumes
      match:
        any:
          - resources:
              kinds:
                - Pod
      preconditions:
        all:
          - key: "{{ request.operation || 'BACKGROUND' }}"
            operator: NotEquals
            value: DELETE
      validate:
        message: "Only the following types of volumes may be used: configMap, csi, downwardAPI, emptyDir, ephemeral, persistentVolumeClaim, projected, and secret."
        deny:
          conditions:
            all:
              - key: "{{ request.object.spec.volumes[].keys(@)[] || '' }}"
                operator: AnyNotIn
                value:
                  - name
                  - configMap
                  - csi
                  - downwardAPI
                  - emptyDir
                  - ephemeral
                  - persistentVolumeClaim
                  - projected
                  - secret
                  - ""