Optionally added separate secondary range for services.

modules/gke-cluster/main.tf

@@ -64,7 +64,7 @@ resource "google_container_cluster" "cluster" {
   ip_allocation_policy {
     // Choose the range, but let GCP pick the IPs within the range
     cluster_secondary_range_name  = var.cluster_secondary_range_name
-    services_secondary_range_name = var.cluster_secondary_range_name
+    services_secondary_range_name = var.services_secondary_range_name != null ? var.services_secondary_range_name : var.cluster_secondary_range_name
   }
 
   # We can optionally control access to the cluster

modules/gke-cluster/variables.tf

@@ -203,3 +203,9 @@ variable "enable_vertical_pod_autoscaling" {
   type        = string
   default     = false
 }
+
+variable "services_secondary_range_name" {
+  description = "The name of the secondary range within the subnetwork for the services to use"
+  type        = string
+  default     = null
+}