feat: Do not create snapshot_identifier when skip_final_snapshot = true (#332)

* Do not create snapshot_identifier when skip_final_snapshot is true

* Set default for skip_final_snapshot to false

* Update docs

Author: air3ijai

README.md

@@ -363,7 +363,7 @@ No modules.
 | <a name="input_security_group_tags"></a> [security\_group\_tags](#input\_security\_group\_tags) | Additional tags for the security group | `map(string)` | `{}` | no |
 | <a name="input_security_group_use_name_prefix"></a> [security\_group\_use\_name\_prefix](#input\_security\_group\_use\_name\_prefix) | Determines whether the security group name (`name`) is used as a prefix | `bool` | `true` | no |
 | <a name="input_serverlessv2_scaling_configuration"></a> [serverlessv2\_scaling\_configuration](#input\_serverlessv2\_scaling\_configuration) | Map of nested attributes with serverless v2 scaling properties. Only valid when `engine_mode` is set to `provisioned` | `map(string)` | `{}` | no |
-| <a name="input_skip_final_snapshot"></a> [skip\_final\_snapshot](#input\_skip\_final\_snapshot) | Determines whether a final snapshot is created before the cluster is deleted. If true is specified, no snapshot is created | `bool` | `null` | no |
+| <a name="input_skip_final_snapshot"></a> [skip\_final\_snapshot](#input\_skip\_final\_snapshot) | Determines whether a final snapshot is created before the cluster is deleted. If true is specified, no snapshot is created | `bool` | `false` | no |
 | <a name="input_snapshot_identifier"></a> [snapshot\_identifier](#input\_snapshot\_identifier) | Specifies whether or not to create this cluster from a snapshot. You can use either the name or ARN when specifying a DB cluster snapshot, or the ARN when specifying a DB snapshot | `string` | `null` | no |
 | <a name="input_source_region"></a> [source\_region](#input\_source\_region) | The source region for an encrypted replica DB cluster | `string` | `null` | no |
 | <a name="input_storage_encrypted"></a> [storage\_encrypted](#input\_storage\_encrypted) | Specifies whether the DB cluster is encrypted. The default is `true` | `bool` | `true` | no |

main.tf

@@ -15,6 +15,8 @@ locals {
   backtrack_window = (var.engine == "aurora-mysql" || var.engine == "aurora") && var.engine_mode != "serverless" ? var.backtrack_window : 0
 
   is_serverless = var.engine_mode == "serverless"
+
+  final_snapshot_identifier_prefix = "${var.final_snapshot_identifier_prefix}-${var.name}-${try(random_id.snapshot_identifier[0].hex, "")}"
 }
 
 ################################################################################
@@ -29,7 +31,7 @@ resource "random_password" "master_password" {
 }
 
 resource "random_id" "snapshot_identifier" {
-  count = local.create_cluster ? 1 : 0
+  count = local.create_cluster && !var.skip_final_snapshot ? 1 : 0
 
   keepers = {
     id = var.name
@@ -81,7 +83,7 @@ resource "aws_rds_cluster" "this" {
   engine                              = var.engine
   engine_mode                         = var.engine_mode
   engine_version                      = var.engine_version
-  final_snapshot_identifier           = "${var.final_snapshot_identifier_prefix}-${var.name}-${try(random_id.snapshot_identifier[0].hex, "")}"
+  final_snapshot_identifier           = var.skip_final_snapshot ? null : local.final_snapshot_identifier_prefix
   global_cluster_identifier           = var.global_cluster_identifier
   iam_database_authentication_enabled = var.iam_database_authentication_enabled
   # iam_roles has been removed from this resource and instead will be used with aws_rds_cluster_role_association below to avoid conflicts per docs

variables.tf

@@ -277,7 +277,7 @@ variable "serverlessv2_scaling_configuration" {
 variable "skip_final_snapshot" {
   description = "Determines whether a final snapshot is created before the cluster is deleted. If true is specified, no snapshot is created"
   type        = bool
-  default     = null
+  default     = false
 }
 
 variable "snapshot_identifier" {