added instance template modifier

main.tf

@@ -18,6 +18,7 @@ module "network" {
 
 module "storage" {
   source = "./modules/storage"
+  project_id=var.project_id
 }
 
 module "autoscale" {

modules/modify-instance-template/main.tf

@@ -0,0 +1,42 @@
+# Change machine type of frontend instance
+resource "google_compute_instance" "frontend" {
+  name = "frontend"
+  zone = "us-central1-f"
+  machine_type = "custom-4-3840"
+}
+
+# Create a new instance template for the frontend instances
+resource "google_compute_instance_template" "fancy_fe_new" {
+  name = "fancy-fe-new"
+  source_instance = google_compute_instance.frontend.self_link
+  source_instance_zone = google_compute_instance.frontend.zone
+
+  disk {
+    source = google_compute_instance.frontend.boot_disk[0].source
+    auto_delete = true
+  }
+
+  network_interface {
+    network = "default"
+    access_config {
+      nat_ip = google_compute_address.fancy_lb_ip.address
+    }
+  }
+}
+
+# Update the instance group with the new instance template
+resource "google_compute_region_instance_group_manager_rolling_update" "fancy_fe_mig_update" {
+  name = "fancy-fe-mig-update"
+  region = "us-central1"
+
+  managed_instance_group = google_compute_instance_group_manager.fancy_fe_mig.self_link
+
+  version {
+    name = "fancy-fe-new"
+    instance_template = google_compute_instance_template.fancy_fe_new.self_link
+  }
+
+  # Optional flags
+  max_surge = 1
+  max_unavailable = 1
+}