fix DNS module internal zone lookup

CHANGELOG.md

@@ -4,6 +4,8 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+- fix DNS module internal zone lookup
+
 ## [1.3.0] - 2020-04-08
 
 - add organization policy module

modules/dns/main.tf

@@ -20,9 +20,11 @@ locals {
     for record in var.recordsets :
     join("/", [record.name, record.type]) => record
   }
-  zone = element(concat(
-    google_dns_managed_zone.non-public, google_dns_managed_zone.public
-  ), 0)
+  zone = try(
+    google_dns_managed_zone.non-public.0, try(
+      google_dns_managed_zone.public.0, null
+    )
+  )
 }
 
 resource "google_dns_managed_zone" "non-public" {

modules/dns/outputs.tf

@@ -26,15 +26,15 @@ output "zone" {
 
 output "name" {
   description = "The DNS zone name."
-  value       = local.zone.name
+  value       = try(local.zone.name, null)
 }
 
 output "domain" {
   description = "The DNS zone domain."
-  value       = local.zone.dns_name
+  value       = try(local.zone.dns_name, null)
 }
 
 output "name_servers" {
   description = "The DNS zone name servers."
-  value       = local.zone.name_servers
+  value       = try(local.zone.name_servers, null)
 }