Revert "Centralise logic for VM tag name."

This reverts commit d2217ee.

cf_internal_networking.tf

@@ -16,10 +16,10 @@ resource "google_compute_firewall" "cf-internal" {
     protocol = "udp"
   }
 
-  target_tags = ["${var.vm_tag}"]
+  target_tags = ["${var.env_name}-vms"]
 
   source_tags = [
-    "${var.vm_tag}",                        // Allows VMs deployed by OpsMan to talk to one another
+    "${var.env_name}-vms",                  // Allows VMs deployed by OpsMan to talk to one another
     "${var.env_name}-ops-manager-external",
   ] // Allows bosh-init running on the OpsMan VM to SSH to the deployed BOSH Director
 }

outputs.tf

@@ -39,7 +39,7 @@ output "service_account_key" {
 }
 
 output "vm_tag" {
-  value = "${var.vm_tag}"
+  value = "${var.env_name}-vms"
 }
 
 output "network_name" {

variables.tf

@@ -6,12 +6,6 @@ variable "env_name" {
   type = "string"
 }
 
-variable "vm_tag" {
-  type        = "string"
-  description = "tag used allow internal network access"
-  default     = "${var.env_name}-vms"
-}
-
 variable "region" {
   type = "string"
 }