From 89a5763625cc60ad1d8b9afd13cfda916e88996a Mon Sep 17 00:00:00 2001
From: Win Gutmann <54120202+winthropgutmann-ef@users.noreply.github.com>
Date: Mon, 18 Mar 2024 20:06:31 -0400
Subject: [PATCH] fix: Separate `db_instance_tags` from merged `tags`
 sub-module input (#544)

Co-authored-by: Bryant Biggs <bryantbiggs@gmail.com>
---
 .pre-commit-config.yaml          | 2 +-
 main.tf                          | 3 ++-
 modules/db_instance/README.md    | 1 +
 modules/db_instance/main.tf      | 2 +-
 modules/db_instance/variables.tf | 6 ++++++
 5 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 395404e8..ade44ffa 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/antonbabenko/pre-commit-terraform
-    rev: v1.88.0
+    rev: v1.88.2
     hooks:
       - id: terraform_fmt
       - id: terraform_docs
diff --git a/main.tf b/main.tf
index f06f12f4..31fefcd9 100644
--- a/main.tf
+++ b/main.tf
@@ -151,7 +151,8 @@ module "db_instance" {
   restore_to_point_in_time = var.restore_to_point_in_time
   s3_import                = var.s3_import
 
-  tags = merge(var.tags, var.db_instance_tags)
+  db_instance_tags = var.db_instance_tags
+  tags             = var.tags
 }
 
 module "db_instance_role_association" {
diff --git a/modules/db_instance/README.md b/modules/db_instance/README.md
index 0edf1309..df849af2 100644
--- a/modules/db_instance/README.md
+++ b/modules/db_instance/README.md
@@ -54,6 +54,7 @@ No modules.
 | <a name="input_create_cloudwatch_log_group"></a> [create\_cloudwatch\_log\_group](#input\_create\_cloudwatch\_log\_group) | Determines whether a CloudWatch log group is created for each `enabled_cloudwatch_logs_exports` | `bool` | `false` | no |
 | <a name="input_create_monitoring_role"></a> [create\_monitoring\_role](#input\_create\_monitoring\_role) | Create IAM role with a defined name that permits RDS to send enhanced monitoring metrics to CloudWatch Logs. | `bool` | `false` | no |
 | <a name="input_custom_iam_instance_profile"></a> [custom\_iam\_instance\_profile](#input\_custom\_iam\_instance\_profile) | RDS custom iam instance profile | `string` | `null` | no |
+| <a name="input_db_instance_tags"></a> [db\_instance\_tags](#input\_db\_instance\_tags) | A map of additional tags for the DB instance | `map(string)` | `{}` | no |
 | <a name="input_db_name"></a> [db\_name](#input\_db\_name) | The DB name to create. If omitted, no database is created initially | `string` | `null` | no |
 | <a name="input_db_subnet_group_name"></a> [db\_subnet\_group\_name](#input\_db\_subnet\_group\_name) | Name of DB subnet group. DB instance will be created in the VPC associated with the DB subnet group. If unspecified, will be created in the default VPC | `string` | `null` | no |
 | <a name="input_delete_automated_backups"></a> [delete\_automated\_backups](#input\_delete\_automated\_backups) | Specifies whether to remove automated backups immediately after the DB instance is deleted | `bool` | `true` | no |
diff --git a/modules/db_instance/main.tf b/modules/db_instance/main.tf
index 325d82cb..2d6765c9 100644
--- a/modules/db_instance/main.tf
+++ b/modules/db_instance/main.tf
@@ -132,7 +132,7 @@ resource "aws_db_instance" "this" {
     }
   }
 
-  tags = var.tags
+  tags = merge(var.tags, var.db_instance_tags)
 
   depends_on = [aws_cloudwatch_log_group.this]
 
diff --git a/modules/db_instance/variables.tf b/modules/db_instance/variables.tf
index 372d4529..e7fb4c33 100644
--- a/modules/db_instance/variables.tf
+++ b/modules/db_instance/variables.tf
@@ -323,6 +323,12 @@ variable "tags" {
   default     = {}
 }
 
+variable "db_instance_tags" {
+  description = "A map of additional tags for the DB instance"
+  type        = map(string)
+  default     = {}
+}
+
 variable "option_group_name" {
   description = "Name of the DB option group to associate."
   type        = string