Provide node_pool_auto_config only when node auto provisioning is enabled for GKE standard cluster (#3275)

* Set node_pool_auto_config for GKE standard cluster only if auto provisioning is enabled

* handle null dereference for terraform cli less than v1.12

* fixed gke-hub test

Explicitly enable node auto provisioning

modules/gke-cluster-standard/main.tf

@@ -88,16 +88,19 @@ resource "google_container_cluster" "cluster" {
       }
     }
   }
-  node_pool_auto_config {
-    network_tags {
-      tags = var.node_pool_auto_config.network_tags
-    }
-    resource_manager_tags = var.node_pool_auto_config.resource_manager_tags
-    node_kubelet_config {
-      insecure_kubelet_readonly_port_enabled = upper(var.node_pool_auto_config.kubelet_readonly_port_enabled)
-    }
-    linux_node_config {
-      cgroup_mode = var.node_pool_auto_config.cgroup_mode
+  dynamic "node_pool_auto_config" {
+    for_each = try(local.cas.enabled, null) == true ? [""] : []
+    content {
+      network_tags {
+        tags = var.node_pool_auto_config.network_tags
+      }
+      resource_manager_tags = var.node_pool_auto_config.resource_manager_tags
+      node_kubelet_config {
+        insecure_kubelet_readonly_port_enabled = upper(var.node_pool_auto_config.kubelet_readonly_port_enabled)
+      }
+      linux_node_config {
+        cgroup_mode = var.node_pool_auto_config.cgroup_mode
+      }
     }
   }
   addons_config {

modules/gke-hub/README.md

@@ -65,6 +65,9 @@ module "cluster_1" {
     dataplane_v2      = true
     workload_identity = true
   }
+  cluster_autoscaling = {
+    enabled = true
+  }
 }
 
 module "hub" {