Customer-Managed Encryption Keys (CMEK) should be used for boot disks

Description

Use Customer-Managed Encryption Keys (CMEK) to encrypt node boot disks using keys managed within Cloud Key Management Service (Cloud KMS). GCE persistent disks are encrypted at rest by default using envelope encryption with keys managed by Google. For additional protection, users can manage the Key Encryption Keys using Cloud KMS.

Remediation

Note: This cannot be remediated by updating an existing cluster. The node pool must either be recreated or a new cluster created.

From the console

To create a new node pool:

  1. Go to the Kubernetes Engine
  2. Select Kubernetes clusters for which node boot disk CMEK is disabled
  3. Click ADD NODE POOL
  4. In the Nodes section, under machine configuration, ensure Boot disk type is Standard persistent disk or SSD persistent disk
  5. Select Enable customer-managed encryption for Boot Disk and select the Cloud KMS encryption key to be used.
  6. Click CREATE

To create a new cluster:

  1. Go to the Kubernetes Engine
  2. Click CREATE and click CONFIGURE for the required cluster mode
  3. Under NODE POOLS, expand the default-pool list and click Nodes
  4. In the Configure node settings pane, select Standard persistent disk or SSD Persistent Disk as the Boot disk type
  5. Select Enable customer-managed encryption for Boot Disk check box and choose the Cloud KMS encryption key to be used
  6. Configure the rest of the cluster settings as required
  7. Click CREATE

From the commandline

  1. Create a new node pool using customer-managed encryption keys for the node boot disk, of disk_type either pd-standard or pd-ssd:
    gcloud container node-pools create <cluster_name> --disk-type <disk_type> --boot-disk-kms-keyprojects/<key_project_id>/locations/<location>/keyRings/<ring_name>/cryptoKeys/<key_name>
  2. Create a cluster using customer-managed encryption keys for the node boot disk, of disk_type either pd-standard or pd-ssd:
    gcloud container clusters create <cluster_name> --disk-type <disk_type> --boot-disk-kms-key projects/<key_project_id>/locations/<location>/keyRings/<ring_name>/cryptoKeys/<key_name>

References