Update

terraform/modules/network/main.tf

@@ -90,3 +90,29 @@ resource "google_compute_firewall" "backend_to_database_3306" {
   source_tags = ["backend"]
   target_tags = ["database"]
 }
+
+resource "google_compute_router" "nat_router" {
+  name    = "${var.project_name}-nat-router"
+  region  = var.region
+  network = google_compute_network.vpc.id
+  project = var.project_name
+}
+
+resource "google_compute_router_nat" "nat" {
+  name                               = "${var.project_name}-cloud-nat"
+  router                             = google_compute_router.nat_router.name
+  region                             = var.region
+  project                            = var.project_name
+  nat_ip_allocate_option             = "AUTO_ONLY"
+  source_subnetwork_ip_ranges_to_nat = "LIST_OF_SUBNETWORKS"
+
+  subnetwork {
+    name                    = google_compute_subnetwork.backend.id
+    source_ip_ranges_to_nat = ["ALL_IP_RANGES"]
+  }
+
+  subnetwork {
+    name                    = google_compute_subnetwork.database.id
+    source_ip_ranges_to_nat = ["ALL_IP_RANGES"]
+  }
+}