Added GKE pubsub notifications

modules/gke-cluster/README.md

@@ -71,6 +71,7 @@ module "cluster-1" {
 | location | Cluster zone or region. | <code title="">string</code> | ✓ |  |
 | name | Cluster name. | <code title="">string</code> | ✓ |  |
 | network | Name or self link of the VPC used for the cluster. Use the self link for Shared VPC. | <code title="">string</code> | ✓ |  |
+| notification_config | GKE Cluster upgrade notifications via PubSub. | <code title="">bool</code> | ✓ |  |
 | project_id | Cluster project id. | <code title="">string</code> | ✓ |  |
 | secondary_range_pods | Subnet secondary range name used for pods. | <code title="">string</code> | ✓ |  |
 | secondary_range_services | Subnet secondary range name used for services. | <code title="">string</code> | ✓ |  |
@@ -116,4 +117,5 @@ module "cluster-1" {
 | location | Cluster location. |  |
 | master_version | Master version. |  |
 | name | Cluster name. |  |
+| notifications | GKE PubSub notifications topic. |  |
 <!-- END TFDOC -->

modules/gke-cluster/main.tf

@@ -277,6 +277,18 @@ resource "google_container_cluster" "cluster" {
       cluster_dns_domain = config.value.cluster_dns_domain
     }
   }
+
+  dynamic "notification_config" {
+
+    for_each = var.notification_config != null ? [""] : []
+    content {
+      pubsub {
+        enabled = var.notification_config
+        topic   = var.notification_config ? google_pubsub_topic.notifications[0].id : null
+      }
+    }
+  }
+
 }
 
 resource "google_compute_network_peering_routes_config" "gke_master" {
@@ -287,3 +299,11 @@ resource "google_compute_network_peering_routes_config" "gke_master" {
   import_custom_routes = var.peering_config.import_routes
   export_custom_routes = var.peering_config.export_routes
 }
+
+resource "google_pubsub_topic" "notifications" {
+  count = var.notification_config ? 1 : 0
+  name  = "gke-pubsub-notifications"
+  labels = {
+    content = "gke-notifications"
+  }
+}

modules/gke-cluster/outputs.tf

@@ -45,3 +45,8 @@ output "name" {
   description = "Cluster name."
   value       = google_container_cluster.cluster.name
 }
+
+output "notifications" {
+  description = "GKE PubSub notifications topic."
+  value       = google_pubsub_topic.notifications.id
+}

modules/gke-cluster/variables.tf

@@ -236,7 +236,10 @@ variable "node_locations" {
   type        = list(string)
   default     = []
 }
-
+variable "notification_config" {
+  description = "GKE Cluster upgrade notifications via PubSub."
+  type        = bool
+}
 variable "peering_config" {
   description = "Configure peering with the master VPC for private clusters."
   type = object({