fix(deps)!: Update Terraform terraform-google-modules/vm/google to v13 (#221)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Andrew Peabody <andrewpeabody@google.com>

Author: renovate[bot]

README.md

@@ -39,7 +39,7 @@ These sections describe requirements for using this module.
 
 The following dependencies must be available:
 
-- [Terraform][terraform] >= v0.12
+- [Terraform][terraform] >= v1.3
 - [Terraform Provider for GCP][terraform-provider-gcp]
 
 ### APIs
@@ -95,7 +95,7 @@ If the user does not share the same domain as the org the bastion is in, you wil
 | preemptible | Allow the instance to be preempted | `bool` | `false` | no |
 | project | The project ID to deploy to | `string` | n/a | yes |
 | random\_role\_id | Enables role random id generation. | `bool` | `true` | no |
-| region | The region where the bastion instance template will live | `string` | `null` | no |
+| region | The region where the bastion instance template will live | `string` | `"us-central1"` | no |
 | resource\_manager\_tags | (Optional) A tag is a key-value pair that can be attached to a Google Cloud resource. You can use tags to conditionally allow or deny policies based on whether a resource has a specific tag. This value is not returned by the API. In Terraform, this value cannot be updated and changing it will recreate the resource. | `map(string)` | `null` | no |
 | scopes | List of scopes to attach to the bastion host | `list(string)` | <pre>[<br>  "cloud-platform"<br>]</pre> | no |
 | service\_account\_email | If set, the service account and its permissions will not be created. The service account being passed in should have at least the roles listed in the `service_account_roles` variable so that logging and OS Login work as expected. | `string` | `""` | no |

docs/upgrading_to_v9.0.md

@@ -0,0 +1,9 @@
+# Upgrading to terraform-google-bastion-host v9.x
+
+The v9.0 release of Google Bastion Host is a backwards incompatible release. 
+Below a list of the breaking changes and the migration instructions.
+
+## ⚠ BREAKING CHANGES
+
+* The `region` variable now defaults to `us-central1` rather than `null` for instance templates.
+* A minimum of Terraform v1.3 is now required.

examples/iap_tunneling/main.tf

@@ -38,9 +38,10 @@ resource "google_service_account" "vm_sa" {
 # A testing VM to allow OS Login + IAP tunneling.
 module "instance_template" {
   source  = "terraform-google-modules/vm/google//modules/instance_template"
-  version = "~> 12.0"
+  version = "~> 13.0"
 
   project_id   = var.project_id
+  region       = "us-west1"
   machine_type = "n1-standard-1"
   subnetwork   = google_compute_subnetwork.subnet.self_link
   service_account = {

examples/simple_example/main.tf

@@ -20,6 +20,7 @@ module "iap_bastion" {
 
   project = var.project_id
   zone    = "us-west1-a"
+  region  = "us-west1"
   network = google_compute_network.network.self_link
   subnet  = google_compute_subnetwork.subnet.self_link
   members = var.members

main.tf

@@ -44,7 +44,7 @@ resource "google_service_account" "bastion_host" {
 
 module "instance_template" {
   source  = "terraform-google-modules/vm/google//modules/instance_template"
-  version = "~> 12.0"
+  version = "~> 13.0"
 
   name_prefix         = var.name_prefix
   project_id          = var.project

modules/bastion-group/main.tf

@@ -37,6 +37,7 @@ module "iap_bastion" {
   additional_networks                = var.additional_networks
   additional_ports                   = var.additional_ports
   zone                               = var.zone
+  region                             = var.region
   random_role_id                     = var.random_role_id
   fw_name_allow_ssh_from_iap         = var.fw_name_allow_ssh_from_iap
   create_instance_from_template      = false
@@ -45,7 +46,7 @@ module "iap_bastion" {
 
 module "mig" {
   source  = "terraform-google-modules/vm/google//modules/mig"
-  version = "~> 12.0"
+  version = "~> 13.0"
 
   project_id        = var.project
   region            = var.region

variables.tf

@@ -177,7 +177,7 @@ variable "region" {
   type = string
 
   description = "The region where the bastion instance template will live"
-  default     = null
+  default     = "us-central1"
 }
 
 variable "random_role_id" {