Require StorageClass

apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: require-storageclass
  annotations:
    policies.kyverno.io/title: Require StorageClass
    policies.kyverno.io/category: Other, Multi-Tenancy
    policies.kyverno.io/severity: medium
    policies.kyverno.io/subject: PersistentVolumeClaim, StatefulSet
    policies.kyverno.io/description: PersistentVolumeClaims (PVCs) and StatefulSets may optionally define a StorageClass to dynamically provision storage. In a multi-tenancy environment where StorageClasses are far more common, it is often better to require storage only be provisioned from these StorageClasses. This policy requires that PVCs and StatefulSets containing volumeClaimTemplates define the storageClassName field with some value.
spec:
  validationFailureAction: Audit
  background: true
  rules:
    - name: pvc-storageclass
      match:
        any:
          - resources:
              kinds:
                - PersistentVolumeClaim
      validate:
        message: PersistentVolumeClaims must define a storageClassName.
        pattern:
          spec:
            storageClassName: "?*"
    - name: ss-storageclass
      match:
        any:
          - resources:
              kinds:
                - StatefulSet
      validate:
        message: StatefulSets must define a storageClassName.
        pattern:
          spec:
            "=(volumeClaimTemplates)":
              - spec:
                  storageClassName: "?*"