feat: Add support for guest_accelerator for the instance_template module (#160)

* Add GPU variable tp the inputs

* Add description to the GPU variable

* Revert README changes

* Generate docs with make generate_docs

* Fix issue with default guest_accelerator setting

* Remove deprecated list() notation in favor of []

Author: Shabirmean

modules/instance_template/README.md

@@ -21,6 +21,7 @@ See the [simple](../../examples/instance_template/simple) for a usage example.
 | disk\_type | Boot disk type, can be either pd-ssd, local-ssd, or pd-standard | `string` | `"pd-standard"` | no |
 | enable\_confidential\_vm | Whether to enable the Confidential VM configuration on the instance. Note that the instance image must support Confidential VMs. See https://cloud.google.com/compute/docs/images | `bool` | `false` | no |
 | enable\_shielded\_vm | Whether to enable the Shielded VM configuration on the instance. Note that the instance image must support Shielded VMs. See https://cloud.google.com/compute/docs/images | `bool` | `false` | no |
+| gpu | GPU information. Type and count of GPU to attach to the instance template. See https://cloud.google.com/compute/docs/gpus more details | <pre>object({<br>    type  = string<br>    count = number<br>  })</pre> | `null` | no |
 | labels | Labels, provided as a map | `map(string)` | `{}` | no |
 | machine\_type | Machine type to create, e.g. n1-standard-1 | `string` | `"n1-standard-1"` | no |
 | metadata | Metadata, provided as a map | `map(string)` | `{}` | no |

modules/instance_template/main.tf

@@ -51,8 +51,9 @@ locals {
   shielded_vm_configs          = var.enable_shielded_vm ? [true] : []
   confidential_instance_config = var.enable_confidential_vm ? [true] : []
 
+  gpu_enabled = var.gpu != null
   on_host_maintenance = (
-    var.preemptible || var.enable_confidential_vm
+    var.preemptible || var.enable_confidential_vm || local.gpu_enabled
     ? "TERMINATE"
     : var.on_host_maintenance
   )
@@ -141,4 +142,12 @@ resource "google_compute_instance_template" "tpl" {
   confidential_instance_config {
     enable_confidential_compute = var.enable_confidential_vm
   }
+
+  dynamic "guest_accelerator" {
+    for_each = local.gpu_enabled ? [var.gpu] : []
+    content {
+      type  = guest_accelerator.value.type
+      count = guest_accelerator.value.count
+    }
+  }
 }

modules/instance_template/variables.tf

@@ -209,3 +209,15 @@ variable "access_config" {
   }))
   default = []
 }
+
+###########################
+# Guest Accelerator (GPU)
+###########################
+variable "gpu" {
+  description = "GPU information. Type and count of GPU to attach to the instance template. See https://cloud.google.com/compute/docs/gpus more details"
+  type = object({
+    type  = string
+    count = number
+  })
+  default = null
+}