From 5149795becce5d635a8f11e6c07f011c7ea349eb Mon Sep 17 00:00:00 2001
From: Ludovico Magnocavallo <ludomagno@google.com>
Date: Wed, 31 Mar 2021 20:01:10 +0200
Subject: [PATCH] Allow using a non-suffixed name in compute-vm (#217)

* allow using a non-suffixed name in compute-vm

* update README
---
 modules/compute-vm/README.md                  |  1 +
 modules/compute-vm/main.tf                    | 12 ++++++++----
 modules/compute-vm/variables.tf               |  6 ++++++
 tests/modules/compute_vm/fixture/main.tf      |  1 +
 tests/modules/compute_vm/fixture/variables.tf |  9 +++++++--
 tests/modules/compute_vm/test_plan.py         |  7 +++++++
 6 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/modules/compute-vm/README.md b/modules/compute-vm/README.md
index 3bee1daa..e025e1f6 100644
--- a/modules/compute-vm/README.md
+++ b/modules/compute-vm/README.md
@@ -283,6 +283,7 @@ module "instance-group" {
 | *service_account_create* | Auto-create service account. | <code title="">bool</code> |  | <code title="">false</code> |
 | *service_account_scopes* | Scopes applied to service account. | <code title="list&#40;string&#41;">list(string)</code> |  | <code title="">[]</code> |
 | *shielded_config* | Shielded VM configuration of the instances. | <code title="object&#40;&#123;&#10;enable_secure_boot          &#61; bool&#10;enable_vtpm                 &#61; bool&#10;enable_integrity_monitoring &#61; bool&#10;&#125;&#41;">object({...})</code> |  | <code title="">null</code> |
+| *single_name* | Do not append progressive count to instance name. | <code title="">bool</code> |  | <code title="">false</code> |
 | *tags* | Instance tags. | <code title="list&#40;string&#41;">list(string)</code> |  | <code title="">[]</code> |
 | *use_instance_template* | Create instance template instead of instances. | <code title="">bool</code> |  | <code title="">false</code> |
 | *zones* | Compute zone, instance will cycle through the list, defaults to the 'b' zone in the region. | <code title="list&#40;string&#41;">list(string)</code> |  | <code title="">[]</code> |
diff --git a/modules/compute-vm/main.tf b/modules/compute-vm/main.tf
index 4c164079..08c0b1b6 100644
--- a/modules/compute-vm/main.tf
+++ b/modules/compute-vm/main.tf
@@ -43,9 +43,13 @@ locals {
     "${pair.0}/${pair.1}" => { role = pair.0, name = pair.1, members = var.iam[pair.0] }
   }
   names = (
-    var.use_instance_template ? { (var.name) = 0 } : {
-      for i in range(0, var.instance_count) : "${var.name}-${i + 1}" => i
-    }
+    var.use_instance_template
+    ? { (var.name) = 0 }
+    : (
+      var.single_name && var.instance_count == 1
+      ? { (var.name) = 0 }
+      : { for i in range(0, var.instance_count) : "${var.name}-${i + 1}" => i }
+    )
   )
   service_account_email = (
     var.service_account_create
@@ -64,7 +68,7 @@ locals {
       ? [
         "https://www.googleapis.com/auth/cloud-platform",
         "https://www.googleapis.com/auth/userinfo.email"
-        ]
+      ]
       : [
         "https://www.googleapis.com/auth/devstorage.read_only",
         "https://www.googleapis.com/auth/logging.write",
diff --git a/modules/compute-vm/variables.tf b/modules/compute-vm/variables.tf
index 489414ca..c96dace7 100644
--- a/modules/compute-vm/variables.tf
+++ b/modules/compute-vm/variables.tf
@@ -230,6 +230,12 @@ variable "service_account_scopes" {
   default     = []
 }
 
+variable "single_name" {
+  description = "Do not append progressive count to instance name."
+  type        = bool
+  default     = false
+}
+
 variable "tags" {
   description = "Instance tags."
   type        = list(string)
diff --git a/tests/modules/compute_vm/fixture/main.tf b/tests/modules/compute_vm/fixture/main.tf
index 143333b4..1690e4d5 100644
--- a/tests/modules/compute_vm/fixture/main.tf
+++ b/tests/modules/compute_vm/fixture/main.tf
@@ -29,4 +29,5 @@ module "test" {
   iam                    = var.iam
   metadata               = var.metadata
   metadata_list          = var.metadata_list
+  single_name            = var.single_name
 }
diff --git a/tests/modules/compute_vm/fixture/variables.tf b/tests/modules/compute_vm/fixture/variables.tf
index f612dbc7..b0039d2c 100644
--- a/tests/modules/compute_vm/fixture/variables.tf
+++ b/tests/modules/compute_vm/fixture/variables.tf
@@ -64,12 +64,17 @@ variable "network_interfaces" {
   }]
 }
 
-variable "use_instance_template" {
+variable "service_account_create" {
   type    = bool
   default = false
 }
 
-variable "service_account_create" {
+variable "single_name" {
+  type    = bool
+  default = false
+}
+
+variable "use_instance_template" {
   type    = bool
   default = false
 }
diff --git a/tests/modules/compute_vm/test_plan.py b/tests/modules/compute_vm/test_plan.py
index 01653933..43697d7b 100644
--- a/tests/modules/compute_vm/test_plan.py
+++ b/tests/modules/compute_vm/test_plan.py
@@ -26,6 +26,13 @@ def test_single_instance(plan_runner):
   assert resources[0]['type'] == 'google_compute_instance'
 
 
+def test_single_instance_single_name(plan_runner):
+  _, resources = plan_runner(FIXTURES_DIR, single_name=1)
+  assert len(resources) == 1
+  assert resources[0]['type'] == 'google_compute_instance'
+  assert resources[0]['values']['name'] == 'test'
+
+
 def test_multiple_instances(plan_runner):
   _, resources = plan_runner(FIXTURES_DIR, instance_count=2)
   assert len(resources) == 2