gke-cluster-autopilot: add monitoring configuration (#1646)

* gke-cluster-autopilot: add monitoring configuration block (monitoring_config)

modules/gke-cluster-autopilot/README.md

@@ -87,6 +87,35 @@ module "cluster-1" {
 # tftest modules=1 resources=1 inventory=logging-config.yaml
 ```
 
+### Monitoring configuration
+
+This example shows how to [configure collection of Kubernetes control plane metrics](https://cloud.google.com/stackdriver/docs/solutions/gke/managing-metrics#enable-control-plane-metrics). The metrics for these components are not collected by default.
+
+> **Note**
+> System metrics collection is pre-configured for Autopilot clusters and cannot be disabled.
+
+> **Warning**
+> GKE **workload metrics** is deprecated and removed in GKE 1.24 and later. Workload metrics is replaced by [Google Cloud Managed Service for Prometheus](https://cloud.google.com/stackdriver/docs/managed-prometheus), which is Google's recommended way to monitor Kubernetes applications by using Cloud Monitoring.
+
+```hcl
+module "cluster-1" {
+  source     = "./fabric/modules/gke-cluster-autopilot"
+  project_id = var.project_id
+  name       = "cluster-1"
+  location   = "europe-west1"
+  vpc_config = {
+    network    = var.vpc.self_link
+    subnetwork = var.subnet.self_link
+  }
+  monitoring_config = {
+    enable_api_server_metrics         = true
+    enable_controller_manager_metrics = true
+    enable_scheduler_metrics          = true
+  }
+}
+# tftest modules=1 resources=1 inventory=monitoring-config-control-plane.yaml
+```
+
 ### Backup for GKE
 
 This example shows how to [enable the Backup for GKE agent and configure a Backup Plan](https://cloud.google.com/kubernetes-engine/docs/add-on/backup-for-gke/concepts/backup-for-gke) for GKE Standard clusters.
@@ -120,9 +149,9 @@ module "cluster-1" {
 | name | description | type | required | default |
 |---|---|:---:|:---:|:---:|
 | [location](variables.tf#L110) | Autopilot cluster are always regional. | <code>string</code> | ✓ |  |
-| [name](variables.tf#L155) | Cluster name. | <code>string</code> | ✓ |  |
-| [project_id](variables.tf#L181) | Cluster project id. | <code>string</code> | ✓ |  |
-| [vpc_config](variables.tf#L209) | 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; string&#10;    services &#61; string&#10;  &#125;&#41;, &#123; pods &#61; &#34;pods&#34;, services &#61; &#34;services&#34; &#125;&#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> | ✓ |  |
+| [name](variables.tf#L170) | Cluster name. | <code>string</code> | ✓ |  |
+| [project_id](variables.tf#L196) | Cluster project id. | <code>string</code> | ✓ |  |
+| [vpc_config](variables.tf#L224) | 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; string&#10;    services &#61; string&#10;  &#125;&#41;, &#123; pods &#61; &#34;pods&#34;, services &#61; &#34;services&#34; &#125;&#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;    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;    region                            &#61; string&#10;    schedule                          &#61; string&#10;    retention_policy_days             &#61; optional&#40;string&#41;&#10;    retention_policy_lock             &#61; optional&#40;bool, false&#41;&#10;    retention_policy_delete_lock_days &#61; optional&#40;string&#41;&#10;  &#125;&#41;&#41;, &#123;&#125;&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code>&#123;&#125;</code> |
 | [description](variables.tf#L37) | Cluster description. | <code>string</code> |  | <code>null</code> |
 | [enable_addons](variables.tf#L43) | 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;  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> |
@@ -132,11 +161,12 @@ module "cluster-1" {
 | [logging_config](variables.tf#L115) | Logging configuration. | <code title="object&#40;&#123;&#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#L126) | 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> |
 | [min_master_version](variables.tf#L149) | Minimum version of the master, defaults to the version of the most recent official release. | <code>string</code> |  | <code>null</code> |
-| [node_locations](variables.tf#L160) | Zones in which the cluster's nodes are located. | <code>list&#40;string&#41;</code> |  | <code>&#91;&#93;</code> |
-| [private_cluster_config](variables.tf#L167) | 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#L186) | Release channel for GKE upgrades. Clusters created in the Autopilot mode must use a release channel. Choose between \"RAPID\", \"REGULAR\", and \"STABLE\". | <code>string</code> |  | <code>&#34;REGULAR&#34;</code> |
-| [service_account](variables.tf#L197) | The Google Cloud Platform Service Account to be used by the node VMs created by GKE Autopilot. | <code>string</code> |  | <code>null</code> |
-| [tags](variables.tf#L203) | Network tags applied to nodes. | <code>list&#40;string&#41;</code> |  | <code>null</code> |
+| [monitoring_config](variables.tf#L155) | Monitoring configuration. System metrics collection cannot be disabled for Autopilot clusters. Control plane metrics are optional. Google Cloud Managed Service for Prometheus is enabled by default. | <code title="object&#40;&#123;&#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_managed_prometheus &#61; optional&#40;bool, true&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code>&#123;&#125;</code> |
+| [node_locations](variables.tf#L175) | Zones in which the cluster's nodes are located. | <code>list&#40;string&#41;</code> |  | <code>&#91;&#93;</code> |
+| [private_cluster_config](variables.tf#L182) | 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#L201) | Release channel for GKE upgrades. Clusters created in the Autopilot mode must use a release channel. Choose between \"RAPID\", \"REGULAR\", and \"STABLE\". | <code>string</code> |  | <code>&#34;REGULAR&#34;</code> |
+| [service_account](variables.tf#L212) | The Google Cloud Platform Service Account to be used by the node VMs created by GKE Autopilot. | <code>string</code> |  | <code>null</code> |
+| [tags](variables.tf#L218) | Network tags applied to nodes. | <code>list&#40;string&#41;</code> |  | <code>null</code> |
 
 ## Outputs
 

modules/gke-cluster-autopilot/main.tf

@@ -203,6 +203,20 @@ resource "google_container_cluster" "cluster" {
     }
   }
 
+  monitoring_config {
+    enable_components = toset(compact([
+      # System metrics collection cannot be disabled for Autopilot clusters.
+      "SYSTEM_COMPONENTS",
+      # Control plane metrics.
+      var.monitoring_config.enable_api_server_metrics ? "APISERVER" : null,
+      var.monitoring_config.enable_controller_manager_metrics ? "CONTROLLER_MANAGER" : null,
+      var.monitoring_config.enable_scheduler_metrics ? "SCHEDULER" : null,
+    ]))
+    managed_prometheus {
+      enabled = var.monitoring_config.enable_managed_prometheus
+    }
+  }
+
   dynamic "notification_config" {
     for_each = var.enable_features.upgrade_notifications != null ? [""] : []
     content {
@@ -305,7 +319,6 @@ resource "google_gke_backup_backup_plan" "backup_plan" {
   }
 }
 
-
 resource "google_compute_network_peering_routes_config" "gke_master" {
   count = (
     try(var.private_cluster_config.peering_config, null) != null ? 1 : 0

modules/gke-cluster-autopilot/variables.tf

@@ -152,6 +152,21 @@ variable "min_master_version" {
   default     = null
 }
 
+variable "monitoring_config" {
+  description = "Monitoring configuration. System metrics collection cannot be disabled for Autopilot clusters. Control plane metrics are optional. Google Cloud Managed Service for Prometheus is enabled by default."
+  type = object({
+    # Control plane metrics
+    enable_api_server_metrics         = optional(bool, false)
+    enable_controller_manager_metrics = optional(bool, false)
+    enable_scheduler_metrics          = optional(bool, false)
+    # Google Cloud Managed Service for Prometheus
+    # GKE Autopilot clusters running GKE version 1.25 or greater must have this on.
+    enable_managed_prometheus = optional(bool, true)
+  })
+  default  = {}
+  nullable = false
+}
+
 variable "name" {
   description = "Cluster name."
   type        = string

tests/modules/gke_cluster_autopilot/examples/monitoring-config-control-plane.yaml

@@ -0,0 +1,27 @@
+# Copyright 2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+values:
+  module.cluster-1.google_container_cluster.cluster:
+    monitoring_config:
+    - enable_components:
+      - APISERVER
+      - CONTROLLER_MANAGER
+      - SCHEDULER
+      - SYSTEM_COMPONENTS
+      managed_prometheus:
+      - enabled: true
+
+counts:
+  google_container_cluster: 1