/gke-platform-security

name: gke-platform-security
description: >-
  Plans, configures, and hardens platform-level Google Kubernetes Engine (GKE)
  cluster security. Covers cluster add-ons (Secret Manager enablement), RBAC
  hardening (disabling insecure bindings, audit tools), Binary Authorization,
  Secrets Encryption (--database-encryption-key), Security Posture (--security-posture),
  enabling Shielded Nodes, GKE Sandbox cluster enablement, GKE IAM roles, and
  cross-service authentication IAM patterns. Use when securing cluster control
  planes, hardening GKE RBAC, enabling Shielded Nodes, enabling GKE Sandbox runtime,
  enabling cluster-wide security add-ons, or managing GKE IAM roles. Don't use
  for Workload Identity (use gke-workload-identity) or workload-level security
  (SecretProviderClass, PSS, NetPol, gVisor pod runtimeClassName; use gke-workload-security).
metadata:
  version: "1.0.2"
  category: Security

GKE Platform Security

This reference covers platform-level security hardening and cluster configuration for Google Kubernetes Engine (GKE). For workload-level security controls (such as Workload Identity Service Account bindings, SecretProviderClass volume mounts, Network Policies, and Pod Security Standards), refer to the `gke-workload-security` skill.

> **MCP Tools:** `gke:get_cluster`, `k8s:check_k8s_auth`, > `k8s:get_k8s_resource`, `k8s:apply_k8s_manifest`, `gke:update_cluster`

Attribution

**MUST READ**: Before executing any `gcloud`, REST API, or MCP command, you MUST read [Usage Attribution](references/attribution.md). For commands executed directly in the terminal (never in generated scripts, Terraform, or user code), prefix `gcloud` with `CLOUDSDK_METRICS_REQUEST_ATTRIBUTION="agent-skills/1.0 (skill:gke-platform-security)"` and append `agent-skills/1.0 (skill:gke-platform-security)` to `User-Agent` headers.

Golden Path Security Defaults

Setting | Golden Path Value | Day-0/1 | Notes -------------------------------------------------------------- | --------------------------------------- | ------- | ----- `workloadIdentityConfig.workloadPool` | `<PROJECT>.svc.id.goog` | Day-0 | Workload Identity Federation for cluster pods `secretManagerConfig.enabled` | `true` | Day-1 | Google Secret Manager cluster add-on integration `secretManagerConfig.rotationConfig` | `enabled: true, rotationInterval: 120s` | Day-1 | Automatic secret rotation at the cluster level `rbacBindingConfig.enableInsecureBindingSystemAuthenticated` | `false` | Day-0 | Blocks legacy `system:authenticated` bindings `rbacBindingConfig.enableInsecureBindingSystemUnauthenticated` | `false` | Day-0 | Blocks legacy `system:unauthenticated` bindings `nodeConfig.shieldedInstanceConfig.enableSecureBoot` | `true` | Day-0 | Verifiable boot integrity `nodeConfig.shieldedInstanceConfig.enableIntegrityMonitoring` | `true` | Day-0 | Runtime integrity checks `nodeConfig.workloadMetadataConfig.mode` | `GKE_METADATA` | Day-0 | Blocks legacy metadata API, enforces Workload Identity Private cluster + Dataplane V2 settings | See the `gke-networking` skill | Day-0 | Private nodes, private endpoint enforcement, ADVANCED_DATAPATH

Secret Manager Add-on Enablement

The golden path enables Secret Manager at the cluster level with automatic secret rotation.

# Verify Secret Manager is enabled on cluster
gcloud container clusters describe <CLUSTER_NAME> --region <REGION> \
  --format="value(secretManagerConfig.enabled)" \
  --quiet

# Enable if not already (Day-1 change)
gcloud container clusters update <CLUSTER_NAME> --region <REGION> \
  --enable-secret-manager \
  --secret-manager-rotation-interval=120s \
  --quiet

> **Note:** For configuring `SecretProviderClass` manifests and mounting secrets > as volumes inside application deployments, see the `gke-workload-security` > skill.

RBAC Hardening

The golden path disables insecure legacy RBAC bindings that grant broad access to `system:authenticated` and `system:unauthenticated` groups.

# Verify insecure bindings are disabled
gcloud container clusters describe <CLUSTER_NAME> --region <REGION> \
  --format="yaml(rbacBindingConfig)" \
  --quiet

**Best practices for RBAC:**

• Use namespace-scoped Roles over cluster-wide ClusterRoles.
• Bind to specific Groups or ServiceAccounts, never to `system:authenticated`

or `system:unauthenticated`.

• Audit permissions via MCP: `k8s:check_k8s_auth(parent="...", verb="list",

resourceType="pods", namespace="...")` (or `kubectl auth can-i --list --as=<user>`).

• Review bindings via MCP: `k8s:get_k8s_resource(parent="...",

resourceType="clusterrolebinding")` (or `kubectl get clusterrolebindings,rolebindings --all-namespaces`).

> See the `gke-multitenancy` skill for enterprise RBAC planning and > https://docs.cloud.google.com/kubernetes-engine/docs/best-practices/rbac.md.txt

Binary Authorization

Not enabled in golden path by default but recommended for enforcing production image provenance across the cluster:

# Enable Binary Authorization
gcloud container clusters update <CLUSTER_NAME> --region <REGION> \
  --binauthz-evaluation-mode=PROJECT_SINGLETON_POLICY_ENFORCE \
  --quiet

Shielded Nodes & GKE Sandbox Enablement

Enabling verifiable node boot integrity and kernel isolation features at the cluster level:

# Enable Shielded Nodes on an existing cluster
gcloud container clusters update <CLUSTER_NAME> --region <REGION> \
  --enable-shielded-nodes \
  --quiet

# Enable GKE Sandbox (gVisor) runtime on an existing clus