Added conditional project designation feature for relevant modules.

README.md

@@ -7,8 +7,18 @@ There are two submodules:
 * Network - a module that creates a VPC with defined subnets
 * Cloud VPN - a module that creates a Cloud VPN
 
-Compute Engine free tier regions: 
+Compute Engine free tier regions:
 
-* Oregon - **us-west1**
+* Oregon (**us-west1**)
-* Iowa - **us-central1**
+  * `us-west1-a`
-* South Carolina - **us-east1**
+  * `us-west1-b`
+  * `us-west1-c`
+* Iowa (**us-central1**)
+  * `us-central1-a`
+  * `us-central1-b`
+  * `us-central1-c`
+  * `us-central1-f`
+* South Carolina (**us-east1**)
+  * `us-east1-b`
+  * `us-east1-c`
+  * `us-east1-d`

main.tf

@@ -7,9 +7,14 @@ terraform {
   }
 }
 
+locals {
+  hub_region = substr(var.hub.zone, 0, length(var.hub.zone) - 2)
+  spoke_region = substr(var.spoke.zone, 0, length(var.spoke.zone) - 2)
+}
+
 provider "google" {
   # Configuration options
-  region  = var.hub.region
+  region  = local.hub_region
   zone    = var.hub.zone
   project = var.hub.project
 }
@@ -18,10 +23,11 @@ module "hub_network" {
   source = "./modules/network"
 
   name = "${var.hub.name}-vpc"
+
   subnets = [{
     name   = "${var.hub.name}-network"
     cidr   = var.hub.cidr
-    region = var.hub.region
+    region = local.hub_region
   }]
 
   nat = true
@@ -30,12 +36,14 @@ module "hub_network" {
 module "spoke_network" {
   source = "./modules/network"
 
-  name = "${var.spoke.name}-vpc"
+  name       = "${var.spoke.name}-vpc"
+  project_id = var.spoke.project
+
   subnets = [
     {
       name   = "${var.spoke.name}-network"
       cidr   = var.spoke.cidr
-      region = var.spoke.region
+      region = local.spoke_region
     }
   ]
 
@@ -70,7 +78,7 @@ module "gw" {
 
   name            = "${var.hub.name}-vpn"
   network_name    = module.hub_network.name
-  region          = var.hub.region
+  region          = local.hub_region
   vpn_external_ip = var.vpn_external_ip
 }
 
@@ -102,6 +110,7 @@ module "vm_spoke" {
   source = "./modules/linux-vm"
 
   name         = "vm-${var.spoke.name}"
+  project_id   = var.spoke.project
   network_name = "${var.spoke.name}-vpc"
   subnet_name  = "${var.spoke.name}-network"
   ssh          = var.ssh
@@ -112,8 +121,7 @@ module "vm_spoke" {
 module "koszewscy_internal_zone" {
   source = "./modules/dns-managed-zone"
 
-  project_id = var.hub.project
+  dns_name = "koszewscy.waw.pl."
-  dns_name   = "koszewscy.waw.pl."
 
   network_id = module.hub_network.id
 

modules/cloud-vpn-tunnel/main.tf

@@ -1,3 +1,5 @@
+data "google_client_config" "default" {}
+
 data "google_compute_vpn_gateway" "gw" {
   name = var.gw_name
 }
@@ -6,12 +8,13 @@ locals {
   vpc_name = regex("networks/([^/]+)$", data.google_compute_vpn_gateway.gw.network)[0]
 }
 
-data google_compute_network network {
+data "google_compute_network" "network" {
   name = local.vpc_name
 }
 
 resource "google_compute_vpn_tunnel" "tunnel" {
   name               = var.name
+  project            = var.project_id != null ? var.project_id : data.google_client_config.default.project
   target_vpn_gateway = data.google_compute_vpn_gateway.gw.id
 
   shared_secret = var.shared_secret
@@ -25,6 +28,7 @@ resource "google_compute_vpn_tunnel" "tunnel" {
 resource "google_compute_route" "route_to_remote_network" {
   count               = length(var.remote_selectors)
   name                = "${data.google_compute_network.network.name}-to-${replace(var.remote_selectors[count.index], "/[./]/", "-")}"
+  project             = var.project_id != null ? var.project_id : data.google_client_config.default.project
   network             = data.google_compute_network.network.name
   dest_range          = var.remote_selectors[count.index]
   next_hop_vpn_tunnel = google_compute_vpn_tunnel.tunnel.id

modules/cloud-vpn-tunnel/variables.tf

@@ -3,6 +3,13 @@ variable "name" {
   type        = string
 }
 
+variable "project_id" {
+  description = "The GCP project ID. If not provided, the default project will be used."
+  type        = string
+  nullable    = true
+  default     = null
+}
+
 variable "gw_name" {
   description = "The name of the VPN gateway"
   type        = string

modules/cloud-vpn/main.tf

@@ -1,14 +1,18 @@
+data "google_client_config" "default" {}
+
 # Cloud VPN
 resource "google_compute_vpn_gateway" "gw" {
   name    = var.name
   network = var.network_name
   region  = var.region
+  project = var.project_id != null ? var.project_id : data.google_client_config.default.project
 }
 
 resource "google_compute_address" "vpn_ip" {
   count = var.vpn_external_ip != null ? 0 : 1
 
   name         = "${var.name}-ip"
+  project      = var.project_id != null ? var.project_id : data.google_client_config.default.project
   region       = var.region
   address_type = "EXTERNAL"
 }
@@ -16,11 +20,12 @@ resource "google_compute_address" "vpn_ip" {
 data "google_compute_address" "vpn_ip" {
   count = var.vpn_external_ip != null ? 1 : 0
 
-  name   = var.vpn_external_ip
+  name = var.vpn_external_ip
 }
 
 resource "google_compute_forwarding_rule" "gw_fw_esp" {
   name        = "fwd-esp"
+  project     = var.project_id != null ? var.project_id : data.google_client_config.default.project
   ip_protocol = "ESP"
   ip_address  = var.vpn_external_ip != null ? data.google_compute_address.vpn_ip[0].address : google_compute_address.vpn_ip[0].address
   target      = google_compute_vpn_gateway.gw.id
@@ -28,6 +33,7 @@ resource "google_compute_forwarding_rule" "gw_fw_esp" {
 
 resource "google_compute_forwarding_rule" "gw_fw_udp_500" {
   name        = "fwd-udp-500"
+  project     = var.project_id != null ? var.project_id : data.google_client_config.default.project
   ip_protocol = "UDP"
   ip_address  = var.vpn_external_ip != null ? data.google_compute_address.vpn_ip[0].address : google_compute_address.vpn_ip[0].address
   port_range  = "500"
@@ -36,6 +42,7 @@ resource "google_compute_forwarding_rule" "gw_fw_udp_500" {
 
 resource "google_compute_forwarding_rule" "gw_fw_udp_4500" {
   name        = "fwd-udp-4500"
+  project     = var.project_id != null ? var.project_id : data.google_client_config.default.project
   ip_protocol = "UDP"
   ip_address  = var.vpn_external_ip != null ? data.google_compute_address.vpn_ip[0].address : google_compute_address.vpn_ip[0].address
   port_range  = "4500"

modules/cloud-vpn/variables.tf

@@ -3,6 +3,13 @@ variable "name" {
   type        = string
 }
 
+variable "project_id" {
+  description = "The GCP project ID. If not provided, the default project will be used."
+  type        = string
+  nullable    = true
+  default     = null
+}
+
 variable "network_name" {
   description = "The name of the network."
   type        = string

modules/dns-managed-zone/main.tf

@@ -1,7 +1,9 @@
+data "google_client_config" "default" {}
+
 resource "google_dns_managed_zone" "zone" {
   dns_name = var.dns_name
   name     = var.zone_name != null ? var.zone_name : "${replace(replace(var.dns_name, "/\\.$/", ""), ".", "-")}-zone"
-  project  = var.project_id
+  project  = var.project_id != null ? var.project_id : data.google_client_config.default.project
 
   visibility = var.network_id != null ? "private" : "public"
 
@@ -38,7 +40,7 @@ resource "google_dns_managed_zone" "zone" {
 
 resource "google_dns_record_set" "records" {
   count   = length(var.resource_records)
-  project = var.project_id
+  project = var.project_id != null ? var.project_id : data.google_client_config.default.project
 
   managed_zone = google_dns_managed_zone.zone.name
   name         = var.resource_records[count.index].name

modules/dns-managed-zone/variables.tf

@@ -1,6 +1,8 @@
 variable "project_id" {
-  description = "The project ID where the managed zone will be created."
+  description = "The GCP project ID. If not provided, the default project will be used."
   type        = string
+  nullable    = true
+  default     = null
 }
 
 variable "dns_name" {

modules/linux-vm/main.tf

@@ -1,7 +1,10 @@
+data "google_client_config" "default" {}
+
 resource "google_compute_instance" "vm_hub" {
   name           = var.name
   machine_type   = var.machine_type
   can_ip_forward = var.can_ip_forward
+  project        = var.project_id != null ? var.project_id : data.google_client_config.default.project
   description    = var.description
 
   boot_disk {
@@ -11,8 +14,9 @@ resource "google_compute_instance" "vm_hub" {
   }
 
   network_interface {
-    network    = var.network_name
+    network            = var.network_name
-    subnetwork = var.subnet_name
+    subnetwork         = var.subnet_name
+    subnetwork_project = var.project_id != null ? var.project_id : data.google_client_config.default.project
   }
 
   metadata = {

modules/linux-vm/variables.tf

@@ -3,6 +3,13 @@ variable "name" {
   type        = string
 }
 
+variable "project_id" {
+  description = "The GCP project ID. If not provided, the default project will be used."
+  type        = string
+  nullable    = true
+  default     = null
+}
+
 variable "machine_type" {
   description = "The machine type of the VM instance."
   type        = string

modules/network/main.tf

@@ -1,13 +1,17 @@
+data "google_client_config" "default" {}
+
 # VPC
 resource "google_compute_network" "network" {
   name                    = var.name
   auto_create_subnetworks = false
+  project                 = var.project_id != null ? var.project_id : data.google_client_config.default.project
 }
 
 # Subnets
 resource "google_compute_subnetwork" "subnet" {
   count         = length(var.subnets)
   name          = var.subnets[count.index].name
+  project       = var.project_id != null ? var.project_id : data.google_client_config.default.project
   ip_cidr_range = var.subnets[count.index].cidr
   region        = var.subnets[count.index].region != null ? var.subnets[count.index].region : var.subnets[0].region
   network       = google_compute_network.network.id
@@ -18,6 +22,7 @@ resource "google_compute_router" "cr" {
   count   = var.nat ? 1 : 0
   name    = "${var.name}-router"
   network = var.name
+  project = var.project_id != null ? var.project_id : data.google_client_config.default.project
 
   depends_on = [google_compute_network.network]
 }
@@ -25,6 +30,7 @@ resource "google_compute_router" "cr" {
 resource "google_compute_router_nat" "nat" {
   count                              = var.nat ? 1 : 0
   name                               = "${var.name}-nat"
+  project                            = var.project_id != null ? var.project_id : data.google_client_config.default.project
   router                             = google_compute_router.cr[0].name
   nat_ip_allocate_option             = "AUTO_ONLY"
   source_subnetwork_ip_ranges_to_nat = "ALL_SUBNETWORKS_ALL_IP_RANGES"

modules/network/variables.tf

@@ -3,6 +3,13 @@ variable "name" {
   type        = string
 }
 
+variable "project_id" {
+  description = "The GCP project ID. If not provided, the default project will be used."
+  type        = string
+  nullable    = true
+  default     = null
+}
+
 # A Cloud NAT will be created in the same region as the first subnet.
 variable "subnets" {
   description = "A list of subnets with names and CIDRs."

variables.tf

@@ -1,7 +1,6 @@
 variable "hub" {
   type = object({
     name    = string
-    region  = string
     zone    = string
     project = string
     cidr    = string
@@ -11,7 +10,6 @@ variable "hub" {
 variable "spoke" {
   type = object({
     name    = string
-    region  = string
     zone    = string
     project = string
     cidr    = string