From 4be80d36836d33efc924bb0f7f3e66b3df88b37f Mon Sep 17 00:00:00 2001
From: Tom Downes <tpdownes@google.com>
Date: Thu, 7 Sep 2023 16:29:37 +0000
Subject: [PATCH] feat: support setting nic_type of instance_template primary
 network interface

---
 modules/instance_template/README.md    |  1 +
 modules/instance_template/main.tf      |  1 +
 modules/instance_template/variables.tf | 11 +++++++++++
 modules/umig/README.md                 |  2 +-
 4 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/modules/instance_template/README.md b/modules/instance_template/README.md
index 12bcbeb1..31d8e5a5 100644
--- a/modules/instance_template/README.md
+++ b/modules/instance_template/README.md
@@ -36,6 +36,7 @@ See the [simple](../../examples/instance_template/simple) for a usage example.
 | name\_prefix | Name prefix for the instance template | `string` | `"default-instance-template"` | no |
 | network | The name or self\_link of the network to attach this interface to. Use network attribute for Legacy or Auto subnetted networks and subnetwork for custom subnetted networks. | `string` | `""` | no |
 | network\_ip | Private IP address to assign to the instance if desired. | `string` | `""` | no |
+| nic\_type | Valid values are "VIRTIO\_NET", "GVNIC" or set to null to accept API default behavior. | `string` | `null` | no |
 | on\_host\_maintenance | Instance availability Policy | `string` | `"MIGRATE"` | no |
 | preemptible | Allow the instance to be preempted | `bool` | `false` | no |
 | project\_id | The GCP project ID | `string` | `null` | no |
diff --git a/modules/instance_template/main.tf b/modules/instance_template/main.tf
index a7ee69b5..1a18c2c5 100644
--- a/modules/instance_template/main.tf
+++ b/modules/instance_template/main.tf
@@ -111,6 +111,7 @@ resource "google_compute_instance_template" "tpl" {
     subnetwork         = var.subnetwork
     subnetwork_project = var.subnetwork_project
     network_ip         = length(var.network_ip) > 0 ? var.network_ip : null
+    nic_type           = var.nic_type
     stack_type         = var.stack_type
     dynamic "access_config" {
       for_each = var.access_config
diff --git a/modules/instance_template/variables.tf b/modules/instance_template/variables.tf
index e7a3d34c..7aec8575 100644
--- a/modules/instance_template/variables.tf
+++ b/modules/instance_template/variables.tf
@@ -190,6 +190,17 @@ variable "network_ip" {
   default     = ""
 }
 
+variable "nic_type" {
+  description = "Valid values are \"VIRTIO_NET\", \"GVNIC\" or set to null to accept API default behavior."
+  type        = string
+  default     = null
+
+  validation {
+    condition     = var.nic_type == null || var.nic_type == "GVNIC" || var.nic_type == "VIRTIO_NET"
+    error_message = "The \"nic_type\" variable must be set to \"VIRTIO_NET\", \"GVNIC\", or null to allow API default selection."
+  }
+}
+
 variable "stack_type" {
   description = "The stack type for this network interface to identify whether the IPv6 feature is enabled or not. Values are `IPV4_IPV6` or `IPV4_ONLY`. Default behavior is equivalent to IPV4_ONLY."
   type        = string
diff --git a/modules/umig/README.md b/modules/umig/README.md
index 7a5862a5..3cda1fa0 100644
--- a/modules/umig/README.md
+++ b/modules/umig/README.md
@@ -29,7 +29,7 @@ See the [simple](https://github.com/terraform-google-modules/terraform-google-vm
 | static\_ips | List of static IPs for VM instances | `list(string)` | `[]` | no |
 | subnetwork | Subnet to deploy to. Only one of network or subnetwork should be specified. | `string` | `""` | no |
 | subnetwork\_project | The project that subnetwork belongs to | `string` | `""` | no |
-| zones | Override the availability zones list to create the resources in. | `list(string)` | `[]` | no |
+| zones | (Optional) List of availability zones to create VM instances in | `list(string)` | `[]` | no |
 
 ## Outputs