Make backup_configuration optional (#14)

* Make backup_configuration optional

* Typo

Author: tun0

locals.tf renamed to _locals.tf

@@ -12,5 +12,6 @@ locals {
 
   # Helper vars for optional blocks. Will either be an empty set (no) or a
   # single item set (yes)
-  needs_maintenance_window = var.primary_instance_name == null ? [0] : []
+  needs_backup_configuration = var.primary_instance_name == null ? [0] : []
+  needs_maintenance_window   = var.primary_instance_name == null ? [0] : []
 }

outputs.tf renamed to _outputs.tf

@@ -15,15 +15,19 @@ resource "google_sql_database_instance" "instance" {
     tier                  = local.tier
     user_labels           = local.labels
 
-    backup_configuration {
-      enabled                        = coalesce(var.backup_config.enabled, var.highly_available)
-      start_time                     = var.backup_config.start_time
-      point_in_time_recovery_enabled = var.backup_config.point_in_time_recovery_enabled
-      location                       = coalesce(var.backup_config.enabled, var.highly_available) ? var.backup_config.location : null
-      transaction_log_retention_days = var.backup_config.transaction_log_retention_days
-      backup_retention_settings {
-        retained_backups = var.backup_config.retained_backups
-        retention_unit   = "COUNT"
+    dynamic "backup_configuration" {
+      for_each = local.needs_backup_configuration
+
+      content {
+        enabled                        = coalesce(var.backup_config.enabled, var.highly_available)
+        start_time                     = var.backup_config.start_time
+        point_in_time_recovery_enabled = var.backup_config.point_in_time_recovery_enabled
+        location                       = coalesce(var.backup_config.enabled, var.highly_available) ? var.backup_config.location : null
+        transaction_log_retention_days = var.backup_config.transaction_log_retention_days
+        backup_retention_settings {
+          retained_backups = var.backup_config.retained_backups
+          retention_unit   = "COUNT"
+        }
       }
     }