Add output variable for master_user_secret (#260)

Co-authored-by: Joe Niland <joe@originalmind.com.au>

Author: thedomeffm

README.md

@@ -475,6 +475,7 @@ Review the [complete example](examples/complete) to see how to use this module.
 |------|-------------|
 | <a name="output_activity_stream_arn"></a> [activity\_stream\_arn](#output\_activity\_stream\_arn) | Activity Stream ARN |
 | <a name="output_activity_stream_name"></a> [activity\_stream\_name](#output\_activity\_stream\_name) | Activity Stream Name |
+| <a name="output_admin_user_secret"></a> [admin\_user\_secret](#output\_admin\_user\_secret) | The secret manager attributes for the managed admin user password (`master_user_secret`). |
 | <a name="output_arn"></a> [arn](#output\_arn) | Amazon Resource Name (ARN) of the cluster |
 | <a name="output_cluster_identifier"></a> [cluster\_identifier](#output\_cluster\_identifier) | Cluster Identifier |
 | <a name="output_cluster_resource_id"></a> [cluster\_resource\_id](#output\_cluster\_resource\_id) | The region-unique, immutable identifie of the cluster |

outputs.tf

@@ -34,6 +34,12 @@ output "port" {
   description = "DB port"
 }
 
+# See: https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/rds_cluster.html#master_user_secret
+output "admin_user_secret" {
+  value       = var.manage_admin_user_password ? concat(aws_rds_cluster.primary[*].master_user_secret) : []
+  description = "The secret manager attributes for the managed admin user password (`master_user_secret`)."
+}
+
 output "master_host" {
   value       = module.dns_master.hostname
   description = "DB Master hostname"