Ability to append numerical suffix even to 1 instance (#70)

* ability to append numerical suffix even to 1 instance
Signed-off-by: Denis Iskandarov <d.iskandarov@gmail.com>

* include use_num_suffix in README.md

README.md

@@ -107,6 +107,7 @@ data "aws_ami" "ubuntu-xenial" {
 | key\_name | The key name to use for the instance | string | `""` | no |
 | monitoring | If true, the launched EC2 instance will have detailed monitoring enabled | string | `"false"` | no |
 | name | Name to be used on all resources as prefix | string | n/a | yes |
+| use\_num\_suffix | Always append numerical suffix to instance name, even if instance_count is 1 | string | `"false"` | no |
 | network\_interface | Customize network interfaces to be attached at instance boot time | list | `<list>` | no |
 | placement\_group | The Placement Group to start the instance in | string | `""` | no |
 | private\_ip | Private IP address to associate with the instance in a VPC | string | `""` | no |

main.tf

 locals {
   is_t_instance_type = "${replace(var.instance_type, "/^t[23]{1}\\..*$/", "1") == "1" ? "1" : "0"}"
+  instance_name      = "${map("Name", (var.instance_count > 1) || (var.use_num_suffix == "true") ? format("%s-%d", var.name, count.index+1) : var.name)}"
 }
 
 ######
@@ -34,7 +35,7 @@ resource "aws_instance" "this" {
   placement_group                      = "${var.placement_group}"
   tenancy                              = "${var.tenancy}"
 
-  tags = "${merge(map("Name", var.instance_count > 1 ? format("%s-%d", var.name, count.index+1) : var.name), var.tags)}"
+  tags = "${merge(locals.instance_name, var.tags)}"
 
   lifecycle {
     # Due to several known issues in Terraform AWS provider related to arguments of aws_instance:
@@ -77,7 +78,7 @@ resource "aws_instance" "this_t2" {
     cpu_credits = "${var.cpu_credits}"
   }
 
-  tags = "${merge(map("Name", var.instance_count > 1 ? format("%s-%d", var.name, count.index+1) : var.name), var.tags)}"
+  tags = "${merge(locals.instance_name, var.tags)}"
 
   lifecycle {
     # Due to several known issues in Terraform AWS provider related to arguments of aws_instance:

variables.tf

@@ -135,3 +135,8 @@ variable "cpu_credits" {
   description = "The credit option for CPU usage (unlimited or standard)"
   default     = "standard"
 }
+
+variable "use_num_suffix" {
+  description = "Always append numerical suffix to instance name, even if instance_count is 1"
+  default     = "false"
+}