← Policy catalog
</> ValidatingAdmissionPolicy · Apache-2.0

Uses a Volume Type Outside the Allowed Set

pod-volume-types

severityHigh resourcePods productKubernetes bundles2

Volume sources outside the allowed set, such as hostPath, gitRepo or flexVolume, mount node filesystem paths or run driver code on the node, opening a route to kubelet credentials and the container runtime socket.

Rejects unless

!has(object.spec.volumes) || object.spec.volumes.all(v,
  has(v.configMap) ||
  has(v.csi) ||
  has(v.downwardAPI) ||
  has(v.emptyDir) ||
  has(v.ephemeral) ||
  has(v.persistentVolumeClaim) ||
  has(v.projected) ||
  has(v.secret)
)

Each item in spec.volumes[*] must set one of: configMap, csi, downwardAPI, emptyDir, ephemeral, persistentVolumeClaim, projected, or secret.

Remediation

Replace the volume with an allowed source (configMap, csi, downwardAPI, emptyDir, ephemeral, persistentVolumeClaim, projected or secret) and expose node-local data through a PersistentVolumeClaim instead. Field: spec.volumes[*].

Applies to

  • pods · v1 · CREATE, UPDATE

Manifest

apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingAdmissionPolicy
metadata:
  name: pod-volume-types
  annotations:
    kubeapt.io/uuid: "d727820a-72b4-4c75-bf4c-17da0e3e4c81"
    security.kubeapt.io/displayName: "Uses a Volume Type Outside the Allowed Set"
    security.kubeapt.io/description: "Volume sources outside the allowed set, such as hostPath, gitRepo or flexVolume, mount node filesystem paths or run driver code on the node, opening a route to kubelet credentials and the container runtime socket."
    security.kubeapt.io/resource: "Pods"
    security.kubeapt.io/severity: "High"
    security.kubeapt.io/remediation: "Replace the volume with an allowed source (configMap, csi, downwardAPI, emptyDir, ephemeral, persistentVolumeClaim, projected or secret) and expose node-local data through a PersistentVolumeClaim instead. Field: spec.volumes[*]."
    security.kubeapt.io/product: "Kubernetes"
spec:
  failurePolicy: Fail
  matchConstraints:
    resourceRules:
    - apiGroups:
      - ''
      apiVersions:
      - v1
      operations:
      - CREATE
      - UPDATE
      resources:
      - pods
  validations:
  - expression: |
      !has(object.spec.volumes) || object.spec.volumes.all(v,
        has(v.configMap) ||
        has(v.csi) ||
        has(v.downwardAPI) ||
        has(v.emptyDir) ||
        has(v.ephemeral) ||
        has(v.persistentVolumeClaim) ||
        has(v.projected) ||
        has(v.secret)
      )
    message: |
      Each item in spec.volumes[*] must set one of: configMap, csi, downwardAPI, emptyDir, ephemeral, persistentVolumeClaim, projected, or secret.

Save it as pod-volume-types.yaml — the commands below assume that name.

Validate with kubeapt

Check a workload against this one policy, before anything is installed on a cluster.

$ kubeapt validate -p ./pod-volume-types.yaml -r ./workload.yaml

Or without the file, from the published policy set — -r takes a directory too:

$ kubeapt policies download && kubeapt validate --policy-name pod-volume-types -r ./manifests

Or against every namespace in the cluster your kubeconfig points at:

$ kubeapt validate --policy-name pod-volume-types -A

Bundles

Source

View policy.yaml on GitHub →