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Version: v1.5 (dev)

Volume Security

Available as of v1.4.0

Harvester v1.4.0 and later versions allow you to encrypt and decrypt virtual machine images. The encryption mechanism utilizes the Linux kernel module dm_crypt and the command-line utility cryptsetup.

Prerequisites​

Prepare the following resources:

  • Secret: A Kubernetes secret is used as the passphrase of dm_crypt. You must specify the value of the CRYPTO_KEY_VALUE field. All other fields are fixed.

    Example Secret:

    apiVersion: v1
    kind: Secret
    metadata:
      name: encryption
      namespace: default
    data:
      CRYPTO_KEY_CIPHER: aes-xts-plain64
      CRYPTO_KEY_HASH: sha256
      CRYPTO_KEY_PROVIDER: secret
      CRYPTO_KEY_SIZE: 256
      CRYPTO_KEY_VALUE: "Your encryption passphrase"
      CRYPTO_PBKDF: argon2i
    important

    You can create a secret in the system namespace using kubectl or the Harvester UI (Edit as YAML feature). Resources in the system namespace are not displayed on the Harvester UI Secrets screen.

  • StorageClass: Images are encrypted using Longhorn, so required fields must be passed to the Longhorn CSI Driver. You can specify the encryption secret when creating a StorageClass. For more information, see Image StorageClass.

    Example of a StorageClass:

    allowVolumeExpansion: true
    apiVersion: storage.k8s.io/v1
    kind: StorageClass
    metadata:
      name: encryption
    parameters:
      csi.storage.k8s.io/node-publish-secret-name: encryption
      csi.storage.k8s.io/node-publish-secret-namespace: default
      csi.storage.k8s.io/node-stage-secret-name: encryption
      csi.storage.k8s.io/node-stage-secret-namespace: default
      csi.storage.k8s.io/provisioner-secret-name: encryption
      csi.storage.k8s.io/provisioner-secret-namespace: default
      encrypted: "true"
      migratable: "true"
      numberOfReplicas: "3"
      staleReplicaTimeout: "2880"
    provisioner: driver.longhorn.io
    reclaimPolicy: Delete
    volumeBindingMode: Immediate
    important

    You can create a secret in the system namespace using the Harvester UI (Edit as YAML feature) and kubectl. Resources in the system namespace are not displayed on the Harvester UI Secrets screen.

Encrypted Volumes​

You can create an encrypted volume using an encrypted StorageClass on the following UI locations:

  • Volumes: Create screen

    create-empty-volume

  • Volumes tab on the Virtual Machine: Create screen

    create-empty-volume

Advanced Usage with Rancher Integration​

The secret is an unencrypted Base64-encoded string. To keep the secret safe, you can use projects and namespaces to isolate permissions. For more information, see Multi-Tenancy.

Limitations​

You cannot perform the following actions:

  • Export a new volume from an encrypted volume
  • Restore an encrypted volume to an unencrypted volume
  • Restore an unencrypted volume to an encrypted volume