diff --git a/modules/gke-cluster-standard/README.md b/modules/gke-cluster-standard/README.md
index 56ea388d86..3018e1c13c 100644
--- a/modules/gke-cluster-standard/README.md
+++ b/modules/gke-cluster-standard/README.md
@@ -310,27 +310,27 @@ module "cluster-1" {
 
 | name | description | type | required | default |
 |---|---|:---:|:---:|:---:|
-| [location](variables.tf#L213) | Cluster zone or region. | <code>string</code> | ✓ |  |
-| [name](variables.tf#L324) | Cluster name. | <code>string</code> | ✓ |  |
-| [project_id](variables.tf#L360) | Cluster project id. | <code>string</code> | ✓ |  |
-| [vpc_config](variables.tf#L371) | VPC-level configuration. | <code title="object&#40;&#123;&#10;  network                &#61; string&#10;  subnetwork             &#61; string&#10;  master_ipv4_cidr_block &#61; optional&#40;string&#41;&#10;  secondary_range_blocks &#61; optional&#40;object&#40;&#123;&#10;    pods     &#61; string&#10;    services &#61; string&#10;  &#125;&#41;&#41;&#10;  secondary_range_names &#61; optional&#40;object&#40;&#123;&#10;    pods     &#61; optional&#40;string, &#34;pods&#34;&#41;&#10;    services &#61; optional&#40;string, &#34;services&#34;&#41;&#10;  &#125;&#41;&#41;&#10;  master_authorized_ranges &#61; optional&#40;map&#40;string&#41;&#41;&#10;  stack_type               &#61; optional&#40;string&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> | ✓ |  |
+| [location](variables.tf#L214) | Cluster zone or region. | <code>string</code> | ✓ |  |
+| [name](variables.tf#L325) | Cluster name. | <code>string</code> | ✓ |  |
+| [project_id](variables.tf#L361) | Cluster project id. | <code>string</code> | ✓ |  |
+| [vpc_config](variables.tf#L372) | VPC-level configuration. | <code title="object&#40;&#123;&#10;  network                &#61; string&#10;  subnetwork             &#61; string&#10;  master_ipv4_cidr_block &#61; optional&#40;string&#41;&#10;  secondary_range_blocks &#61; optional&#40;object&#40;&#123;&#10;    pods     &#61; string&#10;    services &#61; string&#10;  &#125;&#41;&#41;&#10;  secondary_range_names &#61; optional&#40;object&#40;&#123;&#10;    pods     &#61; optional&#40;string, &#34;pods&#34;&#41;&#10;    services &#61; optional&#40;string, &#34;services&#34;&#41;&#10;  &#125;&#41;&#41;&#10;  master_authorized_ranges &#61; optional&#40;map&#40;string&#41;&#41;&#10;  stack_type               &#61; optional&#40;string&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> | ✓ |  |
 | [backup_configs](variables.tf#L17) | Configuration for Backup for GKE. | <code title="object&#40;&#123;&#10;  enable_backup_agent &#61; optional&#40;bool, false&#41;&#10;  backup_plans &#61; optional&#40;map&#40;object&#40;&#123;&#10;    region                            &#61; string&#10;    applications                      &#61; optional&#40;map&#40;list&#40;string&#41;&#41;&#41;&#10;    encryption_key                    &#61; optional&#40;string&#41;&#10;    include_secrets                   &#61; optional&#40;bool, true&#41;&#10;    include_volume_data               &#61; optional&#40;bool, true&#41;&#10;    namespaces                        &#61; optional&#40;list&#40;string&#41;&#41;&#10;    schedule                          &#61; optional&#40;string&#41;&#10;    retention_policy_days             &#61; optional&#40;number&#41;&#10;    retention_policy_lock             &#61; optional&#40;bool, false&#41;&#10;    retention_policy_delete_lock_days &#61; optional&#40;number&#41;&#10;  &#125;&#41;&#41;, &#123;&#125;&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code>&#123;&#125;</code> |
 | [cluster_autoscaling](variables.tf#L38) | Enable and configure limits for Node Auto-Provisioning with Cluster Autoscaler. | <code title="object&#40;&#123;&#10;  autoscaling_profile &#61; optional&#40;string, &#34;BALANCED&#34;&#41;&#10;  auto_provisioning_defaults &#61; optional&#40;object&#40;&#123;&#10;    boot_disk_kms_key &#61; optional&#40;string&#41;&#10;    disk_size         &#61; optional&#40;number&#41;&#10;    disk_type         &#61; optional&#40;string, &#34;pd-standard&#34;&#41;&#10;    image_type        &#61; optional&#40;string&#41;&#10;    oauth_scopes      &#61; optional&#40;list&#40;string&#41;&#41;&#10;    service_account   &#61; optional&#40;string&#41;&#10;    management &#61; optional&#40;object&#40;&#123;&#10;      auto_repair  &#61; optional&#40;bool, true&#41;&#10;      auto_upgrade &#61; optional&#40;bool, true&#41;&#10;    &#125;&#41;&#41;&#10;    shielded_instance_config &#61; optional&#40;object&#40;&#123;&#10;      integrity_monitoring &#61; optional&#40;bool, true&#41;&#10;      secure_boot          &#61; optional&#40;bool, false&#41;&#10;    &#125;&#41;&#41;&#10;    upgrade_settings &#61; optional&#40;object&#40;&#123;&#10;      blue_green &#61; optional&#40;object&#40;&#123;&#10;        node_pool_soak_duration &#61; optional&#40;string&#41;&#10;        standard_rollout_policy &#61; optional&#40;object&#40;&#123;&#10;          batch_percentage    &#61; optional&#40;number&#41;&#10;          batch_node_count    &#61; optional&#40;number&#41;&#10;          batch_soak_duration &#61; optional&#40;string&#41;&#10;        &#125;&#41;&#41;&#10;      &#125;&#41;&#41;&#10;      surge &#61; optional&#40;object&#40;&#123;&#10;        max         &#61; optional&#40;number&#41;&#10;        unavailable &#61; optional&#40;number&#41;&#10;      &#125;&#41;&#41;&#10;    &#125;&#41;&#41;&#10;  &#125;&#41;&#41;&#10;  cpu_limits &#61; optional&#40;object&#40;&#123;&#10;    min &#61; number&#10;    max &#61; number&#10;  &#125;&#41;&#41;&#10;  mem_limits &#61; optional&#40;object&#40;&#123;&#10;    min &#61; number&#10;    max &#61; number&#10;  &#125;&#41;&#41;&#10;  gpu_resources &#61; optional&#40;list&#40;object&#40;&#123;&#10;    resource_type &#61; string&#10;    min           &#61; number&#10;    max           &#61; number&#10;  &#125;&#41;&#41;&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code>null</code> |
-| [deletion_protection](variables.tf#L115) | Whether or not to allow Terraform to destroy the cluster. Unless this field is set to false in Terraform state, a terraform destroy or terraform apply that would delete the cluster will fail. | <code>bool</code> |  | <code>true</code> |
-| [description](variables.tf#L122) | Cluster description. | <code>string</code> |  | <code>null</code> |
-| [enable_addons](variables.tf#L128) | Addons enabled in the cluster (true means enabled). | <code title="object&#40;&#123;&#10;  cloudrun                       &#61; optional&#40;bool, false&#41;&#10;  config_connector               &#61; optional&#40;bool, false&#41;&#10;  dns_cache                      &#61; optional&#40;bool, false&#41;&#10;  gce_persistent_disk_csi_driver &#61; optional&#40;bool, false&#41;&#10;  gcp_filestore_csi_driver       &#61; optional&#40;bool, false&#41;&#10;  gcs_fuse_csi_driver            &#61; optional&#40;bool, false&#41;&#10;  horizontal_pod_autoscaling     &#61; optional&#40;bool, false&#41;&#10;  http_load_balancing            &#61; optional&#40;bool, false&#41;&#10;  istio &#61; optional&#40;object&#40;&#123;&#10;    enable_tls &#61; bool&#10;  &#125;&#41;&#41;&#10;  kalm           &#61; optional&#40;bool, false&#41;&#10;  network_policy &#61; optional&#40;bool, false&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code title="&#123;&#10;  horizontal_pod_autoscaling &#61; true&#10;  http_load_balancing        &#61; true&#10;&#125;">&#123;&#8230;&#125;</code> |
-| [enable_features](variables.tf#L152) | Enable cluster-level features. Certain features allow configuration. | <code title="object&#40;&#123;&#10;  beta_apis            &#61; optional&#40;list&#40;string&#41;&#41;&#10;  binary_authorization &#61; optional&#40;bool, false&#41;&#10;  cost_management      &#61; optional&#40;bool, false&#41;&#10;  dns &#61; optional&#40;object&#40;&#123;&#10;    provider &#61; optional&#40;string&#41;&#10;    scope    &#61; optional&#40;string&#41;&#10;    domain   &#61; optional&#40;string&#41;&#10;  &#125;&#41;&#41;&#10;  database_encryption &#61; optional&#40;object&#40;&#123;&#10;    state    &#61; string&#10;    key_name &#61; string&#10;  &#125;&#41;&#41;&#10;  dataplane_v2         &#61; optional&#40;bool, false&#41;&#10;  fqdn_network_policy  &#61; optional&#40;bool, false&#41;&#10;  gateway_api          &#61; optional&#40;bool, false&#41;&#10;  groups_for_rbac      &#61; optional&#40;string&#41;&#10;  image_streaming      &#61; optional&#40;bool, false&#41;&#10;  intranode_visibility &#61; optional&#40;bool, false&#41;&#10;  l4_ilb_subsetting    &#61; optional&#40;bool, false&#41;&#10;  mesh_certificates    &#61; optional&#40;bool&#41;&#10;  pod_security_policy  &#61; optional&#40;bool, false&#41;&#10;  resource_usage_export &#61; optional&#40;object&#40;&#123;&#10;    dataset                              &#61; string&#10;    enable_network_egress_metering       &#61; optional&#40;bool&#41;&#10;    enable_resource_consumption_metering &#61; optional&#40;bool&#41;&#10;  &#125;&#41;&#41;&#10;  service_external_ips &#61; optional&#40;bool, true&#41;&#10;  shielded_nodes       &#61; optional&#40;bool, false&#41;&#10;  tpu                  &#61; optional&#40;bool, false&#41;&#10;  upgrade_notifications &#61; optional&#40;object&#40;&#123;&#10;    topic_id &#61; optional&#40;string&#41;&#10;  &#125;&#41;&#41;&#10;  vertical_pod_autoscaling &#61; optional&#40;bool, false&#41;&#10;  workload_identity        &#61; optional&#40;bool, true&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code title="&#123;&#10;  workload_identity &#61; true&#10;&#125;">&#123;&#8230;&#125;</code> |
-| [issue_client_certificate](variables.tf#L201) | Enable issuing client certificate. | <code>bool</code> |  | <code>false</code> |
-| [labels](variables.tf#L207) | Cluster resource labels. | <code>map&#40;string&#41;</code> |  | <code>null</code> |
-| [logging_config](variables.tf#L218) | Logging configuration. | <code title="object&#40;&#123;&#10;  enable_system_logs             &#61; optional&#40;bool, true&#41;&#10;  enable_workloads_logs          &#61; optional&#40;bool, false&#41;&#10;  enable_api_server_logs         &#61; optional&#40;bool, false&#41;&#10;  enable_scheduler_logs          &#61; optional&#40;bool, false&#41;&#10;  enable_controller_manager_logs &#61; optional&#40;bool, false&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code>&#123;&#125;</code> |
-| [maintenance_config](variables.tf#L239) | Maintenance window configuration. | <code title="object&#40;&#123;&#10;  daily_window_start_time &#61; optional&#40;string&#41;&#10;  recurring_window &#61; optional&#40;object&#40;&#123;&#10;    start_time &#61; string&#10;    end_time   &#61; string&#10;    recurrence &#61; string&#10;  &#125;&#41;&#41;&#10;  maintenance_exclusions &#61; optional&#40;list&#40;object&#40;&#123;&#10;    name       &#61; string&#10;    start_time &#61; string&#10;    end_time   &#61; string&#10;    scope      &#61; optional&#40;string&#41;&#10;  &#125;&#41;&#41;&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code title="&#123;&#10;  daily_window_start_time &#61; &#34;03:00&#34;&#10;  recurring_window        &#61; null&#10;  maintenance_exclusion   &#61; &#91;&#93;&#10;&#125;">&#123;&#8230;&#125;</code> |
-| [max_pods_per_node](variables.tf#L262) | Maximum number of pods per node in this cluster. | <code>number</code> |  | <code>110</code> |
-| [min_master_version](variables.tf#L268) | Minimum version of the master, defaults to the version of the most recent official release. | <code>string</code> |  | <code>null</code> |
-| [monitoring_config](variables.tf#L274) | Monitoring configuration. Google Cloud Managed Service for Prometheus is enabled by default. | <code title="object&#40;&#123;&#10;  enable_system_metrics &#61; optional&#40;bool, true&#41;&#10;  enable_api_server_metrics         &#61; optional&#40;bool, false&#41;&#10;  enable_controller_manager_metrics &#61; optional&#40;bool, false&#41;&#10;  enable_scheduler_metrics          &#61; optional&#40;bool, false&#41;&#10;  enable_daemonset_metrics   &#61; optional&#40;bool, false&#41;&#10;  enable_deployment_metrics  &#61; optional&#40;bool, false&#41;&#10;  enable_hpa_metrics         &#61; optional&#40;bool, false&#41;&#10;  enable_pod_metrics         &#61; optional&#40;bool, false&#41;&#10;  enable_statefulset_metrics &#61; optional&#40;bool, false&#41;&#10;  enable_storage_metrics     &#61; optional&#40;bool, false&#41;&#10;  enable_managed_prometheus &#61; optional&#40;bool, true&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code>&#123;&#125;</code> |
-| [node_config](variables.tf#L329) | Node-level configuration. | <code title="object&#40;&#123;&#10;  boot_disk_kms_key &#61; optional&#40;string&#41;&#10;  service_account   &#61; optional&#40;string&#41;&#10;  tags              &#61; optional&#40;list&#40;string&#41;&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code>&#123;&#125;</code> |
-| [node_locations](variables.tf#L339) | Zones in which the cluster's nodes are located. | <code>list&#40;string&#41;</code> |  | <code>&#91;&#93;</code> |
-| [private_cluster_config](variables.tf#L346) | Private cluster configuration. | <code title="object&#40;&#123;&#10;  enable_private_endpoint &#61; optional&#40;bool&#41;&#10;  master_global_access    &#61; optional&#40;bool&#41;&#10;  peering_config &#61; optional&#40;object&#40;&#123;&#10;    export_routes &#61; optional&#40;bool&#41;&#10;    import_routes &#61; optional&#40;bool&#41;&#10;    project_id    &#61; optional&#40;string&#41;&#10;  &#125;&#41;&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code>null</code> |
-| [release_channel](variables.tf#L365) | Release channel for GKE upgrades. | <code>string</code> |  | <code>null</code> |
+| [deletion_protection](variables.tf#L116) | Whether or not to allow Terraform to destroy the cluster. Unless this field is set to false in Terraform state, a terraform destroy or terraform apply that would delete the cluster will fail. | <code>bool</code> |  | <code>true</code> |
+| [description](variables.tf#L123) | Cluster description. | <code>string</code> |  | <code>null</code> |
+| [enable_addons](variables.tf#L129) | Addons enabled in the cluster (true means enabled). | <code title="object&#40;&#123;&#10;  cloudrun                       &#61; optional&#40;bool, false&#41;&#10;  config_connector               &#61; optional&#40;bool, false&#41;&#10;  dns_cache                      &#61; optional&#40;bool, false&#41;&#10;  gce_persistent_disk_csi_driver &#61; optional&#40;bool, false&#41;&#10;  gcp_filestore_csi_driver       &#61; optional&#40;bool, false&#41;&#10;  gcs_fuse_csi_driver            &#61; optional&#40;bool, false&#41;&#10;  horizontal_pod_autoscaling     &#61; optional&#40;bool, false&#41;&#10;  http_load_balancing            &#61; optional&#40;bool, false&#41;&#10;  istio &#61; optional&#40;object&#40;&#123;&#10;    enable_tls &#61; bool&#10;  &#125;&#41;&#41;&#10;  kalm           &#61; optional&#40;bool, false&#41;&#10;  network_policy &#61; optional&#40;bool, false&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code title="&#123;&#10;  horizontal_pod_autoscaling &#61; true&#10;  http_load_balancing        &#61; true&#10;&#125;">&#123;&#8230;&#125;</code> |
+| [enable_features](variables.tf#L153) | Enable cluster-level features. Certain features allow configuration. | <code title="object&#40;&#123;&#10;  beta_apis            &#61; optional&#40;list&#40;string&#41;&#41;&#10;  binary_authorization &#61; optional&#40;bool, false&#41;&#10;  cost_management      &#61; optional&#40;bool, false&#41;&#10;  dns &#61; optional&#40;object&#40;&#123;&#10;    provider &#61; optional&#40;string&#41;&#10;    scope    &#61; optional&#40;string&#41;&#10;    domain   &#61; optional&#40;string&#41;&#10;  &#125;&#41;&#41;&#10;  database_encryption &#61; optional&#40;object&#40;&#123;&#10;    state    &#61; string&#10;    key_name &#61; string&#10;  &#125;&#41;&#41;&#10;  dataplane_v2         &#61; optional&#40;bool, false&#41;&#10;  fqdn_network_policy  &#61; optional&#40;bool, false&#41;&#10;  gateway_api          &#61; optional&#40;bool, false&#41;&#10;  groups_for_rbac      &#61; optional&#40;string&#41;&#10;  image_streaming      &#61; optional&#40;bool, false&#41;&#10;  intranode_visibility &#61; optional&#40;bool, false&#41;&#10;  l4_ilb_subsetting    &#61; optional&#40;bool, false&#41;&#10;  mesh_certificates    &#61; optional&#40;bool&#41;&#10;  pod_security_policy  &#61; optional&#40;bool, false&#41;&#10;  resource_usage_export &#61; optional&#40;object&#40;&#123;&#10;    dataset                              &#61; string&#10;    enable_network_egress_metering       &#61; optional&#40;bool&#41;&#10;    enable_resource_consumption_metering &#61; optional&#40;bool&#41;&#10;  &#125;&#41;&#41;&#10;  service_external_ips &#61; optional&#40;bool, true&#41;&#10;  shielded_nodes       &#61; optional&#40;bool, false&#41;&#10;  tpu                  &#61; optional&#40;bool, false&#41;&#10;  upgrade_notifications &#61; optional&#40;object&#40;&#123;&#10;    topic_id &#61; optional&#40;string&#41;&#10;  &#125;&#41;&#41;&#10;  vertical_pod_autoscaling &#61; optional&#40;bool, false&#41;&#10;  workload_identity        &#61; optional&#40;bool, true&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code title="&#123;&#10;  workload_identity &#61; true&#10;&#125;">&#123;&#8230;&#125;</code> |
+| [issue_client_certificate](variables.tf#L202) | Enable issuing client certificate. | <code>bool</code> |  | <code>false</code> |
+| [labels](variables.tf#L208) | Cluster resource labels. | <code>map&#40;string&#41;</code> |  | <code>null</code> |
+| [logging_config](variables.tf#L219) | Logging configuration. | <code title="object&#40;&#123;&#10;  enable_system_logs             &#61; optional&#40;bool, true&#41;&#10;  enable_workloads_logs          &#61; optional&#40;bool, false&#41;&#10;  enable_api_server_logs         &#61; optional&#40;bool, false&#41;&#10;  enable_scheduler_logs          &#61; optional&#40;bool, false&#41;&#10;  enable_controller_manager_logs &#61; optional&#40;bool, false&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code>&#123;&#125;</code> |
+| [maintenance_config](variables.tf#L240) | Maintenance window configuration. | <code title="object&#40;&#123;&#10;  daily_window_start_time &#61; optional&#40;string&#41;&#10;  recurring_window &#61; optional&#40;object&#40;&#123;&#10;    start_time &#61; string&#10;    end_time   &#61; string&#10;    recurrence &#61; string&#10;  &#125;&#41;&#41;&#10;  maintenance_exclusions &#61; optional&#40;list&#40;object&#40;&#123;&#10;    name       &#61; string&#10;    start_time &#61; string&#10;    end_time   &#61; string&#10;    scope      &#61; optional&#40;string&#41;&#10;  &#125;&#41;&#41;&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code title="&#123;&#10;  daily_window_start_time &#61; &#34;03:00&#34;&#10;  recurring_window        &#61; null&#10;  maintenance_exclusion   &#61; &#91;&#93;&#10;&#125;">&#123;&#8230;&#125;</code> |
+| [max_pods_per_node](variables.tf#L263) | Maximum number of pods per node in this cluster. | <code>number</code> |  | <code>110</code> |
+| [min_master_version](variables.tf#L269) | Minimum version of the master, defaults to the version of the most recent official release. | <code>string</code> |  | <code>null</code> |
+| [monitoring_config](variables.tf#L275) | Monitoring configuration. Google Cloud Managed Service for Prometheus is enabled by default. | <code title="object&#40;&#123;&#10;  enable_system_metrics &#61; optional&#40;bool, true&#41;&#10;  enable_api_server_metrics         &#61; optional&#40;bool, false&#41;&#10;  enable_controller_manager_metrics &#61; optional&#40;bool, false&#41;&#10;  enable_scheduler_metrics          &#61; optional&#40;bool, false&#41;&#10;  enable_daemonset_metrics   &#61; optional&#40;bool, false&#41;&#10;  enable_deployment_metrics  &#61; optional&#40;bool, false&#41;&#10;  enable_hpa_metrics         &#61; optional&#40;bool, false&#41;&#10;  enable_pod_metrics         &#61; optional&#40;bool, false&#41;&#10;  enable_statefulset_metrics &#61; optional&#40;bool, false&#41;&#10;  enable_storage_metrics     &#61; optional&#40;bool, false&#41;&#10;  enable_managed_prometheus &#61; optional&#40;bool, true&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code>&#123;&#125;</code> |
+| [node_config](variables.tf#L330) | Node-level configuration. | <code title="object&#40;&#123;&#10;  boot_disk_kms_key &#61; optional&#40;string&#41;&#10;  service_account   &#61; optional&#40;string&#41;&#10;  tags              &#61; optional&#40;list&#40;string&#41;&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code>&#123;&#125;</code> |
+| [node_locations](variables.tf#L340) | Zones in which the cluster's nodes are located. | <code>list&#40;string&#41;</code> |  | <code>&#91;&#93;</code> |
+| [private_cluster_config](variables.tf#L347) | Private cluster configuration. | <code title="object&#40;&#123;&#10;  enable_private_endpoint &#61; optional&#40;bool&#41;&#10;  master_global_access    &#61; optional&#40;bool&#41;&#10;  peering_config &#61; optional&#40;object&#40;&#123;&#10;    export_routes &#61; optional&#40;bool&#41;&#10;    import_routes &#61; optional&#40;bool&#41;&#10;    project_id    &#61; optional&#40;string&#41;&#10;  &#125;&#41;&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code>null</code> |
+| [release_channel](variables.tf#L366) | Release channel for GKE upgrades. | <code>string</code> |  | <code>null</code> |
 
 ## Outputs
 
diff --git a/modules/gke-cluster-standard/variables.tf b/modules/gke-cluster-standard/variables.tf
index 9fceb4be14..1683cd1048 100644
--- a/modules/gke-cluster-standard/variables.tf
+++ b/modules/gke-cluster-standard/variables.tf
@@ -94,7 +94,8 @@ variable "cluster_autoscaling" {
   }
   validation {
     condition = (
-      var.cluster_autoscaling == null ? true : contains(
+      try(var.cluster_autoscaling, null) == null ||
+      try(var.cluster_autoscaling.auto_provisioning_defaults, null) == null ? true : contains(
         ["pd-standard", "pd-ssd", "pd-balanced"],
       var.cluster_autoscaling.auto_provisioning_defaults.disk_type)
     )