Consider GKE Sandbox For Running Untrusted Workloads

#!/usr/bin/env bash
#
# Report GKE Sandbox (gVisor) status for all node pools in all clusters in a project.
# REQUIREMENTS:
#   - gcloud CLI authenticated and configured
#   - jq installed
#
# USAGE:
#   PROJECT_ID="my-project" ./check_gke_sandbox.sh
#

set -euo pipefail

PROJECT_ID="${PROJECT_ID:-}"

if [[ -z "${PROJECT_ID}" ]]; then
  echo "ERROR: Set PROJECT_ID environment variable." >&2
  exit 1
fi

echo "Project: ${PROJECT_ID}"
echo "Time:    $(date -Iseconds)"
echo

# List all clusters (both zonal and regional)
clusters_json="$(gcloud container clusters list \
  --project "${PROJECT_ID}" \
  --format='json(name,location,endpoint,resourceLabels,loggingService,monitoringService)')"

if [[ "$(echo "${clusters_json}" | jq 'length')" -eq 0 ]]; then
  echo "No GKE clusters found in project ${PROJECT_ID}."
  exit 0
fi

echo "${clusters_json}" | jq -r '.[] | @base64' | while read -r cluster_b64; do
  _jq() { echo "${cluster_b64}" | base64 --decode | jq -r "${1}"; }

  CLUSTER_NAME="$(_jq '.name')"
  LOCATION="$(_jq '.location')"

  echo "================================================================================"
  echo "Cluster: ${CLUSTER_NAME}"
  echo "Location: ${LOCATION}"
  echo

  # List node pools for this cluster
  node_pools_json="$(gcloud container node-pools list \
    --cluster "${CLUSTER_NAME}" \
    --location "${LOCATION}" \
    --project "${PROJECT_ID}" \
    --format='json(name,config.imageType,config.sandboxConfig)')"

  if [[ "$(echo "${node_pools_json}" | jq 'length')" -eq 0 ]]; then
    echo "  No node pools found."
    echo
    continue
  fi

  echo "  Node pools:"
  echo "${node_pools_json}" | jq -r '.[] | @base64' | while read -r np_b64; do
    _npjq() { echo "${np_b64}" | base64 --decode | jq -r "${1}"; }

    NP_NAME="$(_npjq '.name')"
    IMAGE_TYPE="$(_npjq '.config.imageType // "UNKNOWN"')"
    SANDBOX_TYPE="$(_npjq '.config.sandboxConfig.type // "NONE"')"

    # Simple classification
    if [[ "${SANDBOX_TYPE}" == "GVISOR" ]]; then
      STATUS="SANDBOX_ENABLED"
    else
      STATUS="SANDBOX_DISABLED"
    fi

    echo "    - nodePool: ${NP_NAME}"
    echo "        imageType:   ${IMAGE_TYPE}"
    echo "        sandboxType: ${SANDBOX_TYPE}"
    echo "        status:      ${STATUS}"
  done

  echo
done

cat <<'EOF'

INTERPRETING RESULTS
--------------------
For each node pool:

- sandboxType == "GVISOR" and status == "SANDBOX_ENABLED"
    => GKE Sandbox (gVisor) is enabled for that node pool.

- sandboxType == "NONE" or sandboxType is empty and status == "SANDBOX_DISABLED"
    => GKE Sandbox is NOT enabled for that node pool.

WHAT INDICATES A PROBLEM
------------------------
- If you have workloads that are untrusted, multi-tenant, or high-risk and they
  are scheduled on node pools where:
    - sandboxType is "NONE" (or absent), i.e., SANDBOX_DISABLED, and
    - imageType is NOT explicitly using sandbox (no gVisor),
  then this is a potential finding against CIS GKE 5.10.3.

Next steps must be decided manually:
- Identify which workloads are untrusted/risky.
- Ensure those workloads are scheduled onto node pools with sandboxType "GVISOR".
- Consider creating dedicated gVisor-enabled node pools and using node selectors
  / taints / tolerations to isolate untrusted workloads onto them.
EOF