fix: update parameter group to fix name vs. name_prefix

Author: bryantbiggs

README.md

@@ -237,6 +237,7 @@ No resources.
 | options | A list of Options to apply. | `any` | `[]` | no |
 | parameter\_group\_description | Description of the DB parameter group to create | `string` | `""` | no |
 | parameter\_group\_name | Name of the DB parameter group to associate or create | `string` | `""` | no |
+| parameter\_group\_use\_name\_prefix | Determines whether to use `parameter_group_name` as is or create a unique name beginning with the `parameter_group_name` as the prefix | `bool` | `true` | no |
 | parameters | A list of DB parameters (map) to apply | `list(map(string))` | `[]` | no |
 | password | Password for the master DB user. Note that this may show up in logs, and it will be stored in the state file | `string` | n/a | yes |
 | performance\_insights\_enabled | Specifies whether Performance Insights are enabled | `bool` | `false` | no |
@@ -254,7 +255,6 @@ No resources.
 | tags | A mapping of tags to assign to all resources | `map(string)` | `{}` | no |
 | timeouts | (Optional) Updated Terraform resource management timeouts. Applies to `aws_db_instance` in particular to permit resource management times | `map(string)` | <pre>{<br>  "create": "40m",<br>  "delete": "40m",<br>  "update": "80m"<br>}</pre> | no |
 | timezone | (Optional) Time zone of the DB instance. timezone is currently only supported by Microsoft SQL Server. The timezone can only be set on creation. See MSSQL User Guide for more information. | `string` | `""` | no |
-| use\_parameter\_group\_name\_prefix | Whether to use the parameter group name prefix or not | `bool` | `true` | no |
 | username | Username for the master DB user | `string` | n/a | yes |
 | vpc\_security\_group\_ids | List of VPC security groups to associate | `list(string)` | `[]` | no |
 

examples/option-groups/README.md renamed to examples/groups/README.md

@@ -1,6 +1,6 @@
-# Example usage of option groups
+# Example usage of option and parameter groups
 
-Configuration in this directory creates various option groups depending on the configuration specified - no other resources are created.
+Configuration in this directory creates various option and parameter groups depending on the configuration specified - no other resources are created.
 
 ## Usage
 

examples/option-groups/main.tf renamed to examples/groups/main.tf

@@ -12,23 +12,24 @@ locals {
 }
 
 ################################################################################
-# Default Postgres option group
-# This should NOT create anything since option groups are not supported for PostgreSQL
-# https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithOptionGroups.html
+# Default Postgres
 ################################################################################
 
 module "default_postgres" {
   source = "../../"
 
   identifier = local.name
 
-  create_db_instance        = false
-  parameter_group_name      = "foo"
-  create_db_parameter_group = false
-  db_subnet_group_name      = "foo"
-  create_db_subnet_group    = false
+  # This should NOT create an option group since they are not supported for PostgreSQL
+  # https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithOptionGroups.html
+
+  parameter_group_name = "${local.name}-default-postgresql"
+
+  db_subnet_group_name   = "foo"
+  create_db_subnet_group = false
 
   # All available versions: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_PostgreSQL.html#PostgreSQL.Concepts
+  create_db_instance   = false
   engine               = "postgres"
   engine_version       = "11.10"
   family               = "postgres11" # DB parameter group
@@ -48,9 +49,7 @@ module "default_postgres" {
 }
 
 ################################################################################
-# Default MySQL Option Group w/ name prefix used
-# This should create a MySQL option group
-# https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithOptionGroups.html
+# Default MySQL
 ################################################################################
 
 module "default_mysql" {
@@ -60,13 +59,13 @@ module "default_mysql" {
 
   option_group_name = "${local.name}-default-mysql"
 
-  create_db_instance        = false
-  parameter_group_name      = "foo"
-  create_db_parameter_group = false
-  db_subnet_group_name      = "foo"
-  create_db_subnet_group    = false
+  parameter_group_name = "${local.name}-default-mysql"
+
+  db_subnet_group_name   = "foo"
+  create_db_subnet_group = false
 
   # All available versions: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_PostgreSQL.html#PostgreSQL.Concepts
+  create_db_instance   = false
   engine               = "mysql"
   engine_version       = "8.0.20"
   family               = "mysql8.0" # DB parameter group
@@ -86,26 +85,25 @@ module "default_mysql" {
 }
 
 ################################################################################
-# Default MySQL option group w/o name prefix
-# This should create a MySQL option group
-# https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithOptionGroups.html
+# Default MySQL w/o name prefix
 ################################################################################
 
 module "default_mysql_name" {
   source = "../../"
 
   identifier = local.name
 
-  option_group_name            = "${local.name}-default-mysql"
+  option_group_name            = "${local.name}-default-mysql-name"
   option_group_use_name_prefix = false
 
-  create_db_instance        = false
-  parameter_group_name      = "foo"
-  create_db_parameter_group = false
-  db_subnet_group_name      = "foo"
-  create_db_subnet_group    = false
+  parameter_group_name            = "${local.name}-default-mysql-name"
+  parameter_group_use_name_prefix = false
+
+  db_subnet_group_name   = "foo"
+  create_db_subnet_group = false
 
   # All available versions: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_PostgreSQL.html#PostgreSQL.Concepts
+  create_db_instance   = false
   engine               = "mysql"
   engine_version       = "8.0.20"
   family               = "mysql8.0" # DB parameter group
@@ -125,9 +123,7 @@ module "default_mysql_name" {
 }
 
 ################################################################################
-# BYO MySQL Option Group
-# This should NOT create a MySQL option group - the user is specifying an option group to use
-# https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithOptionGroups.html
+# BYO MySQL
 ################################################################################
 
 module "byo_mysql" {
@@ -138,13 +134,14 @@ module "byo_mysql" {
   create_db_option_group = false
   option_group_name      = "bringMyOwnOptionGroupName"
 
-  create_db_instance        = false
-  parameter_group_name      = "foo"
   create_db_parameter_group = false
-  db_subnet_group_name      = "foo"
-  create_db_subnet_group    = false
+  parameter_group_name      = "bringMyOwnParameterGroupName"
+
+  db_subnet_group_name   = "foo"
+  create_db_subnet_group = false
 
   # All available versions: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_PostgreSQL.html#PostgreSQL.Concepts
+  create_db_instance   = false
   engine               = "mysql"
   engine_version       = "8.0.20"
   family               = "mysql8.0" # DB parameter group

examples/option-groups/outputs.tf renamed to examples/groups/outputs.tf

@@ -9,6 +9,16 @@ output "default_postgres_option_group_arn" {
   value       = module.default_postgres.this_db_option_group_arn
 }
 
+output "default_postgres_parameter_group_id" {
+  description = "The db parameter group id"
+  value       = module.default_postgres.this_db_parameter_group_id
+}
+
+output "default_postgres_parameter_group_arn" {
+  description = "The ARN of the db parameter group"
+  value       = module.default_postgres.this_db_parameter_group_arn
+}
+
 # Default MySQL
 output "default_mysql_option_group_id" {
   description = "The ID of the default MySQL option group"
@@ -20,6 +30,16 @@ output "default_mysql_option_group_arn" {
   value       = module.default_mysql.this_db_option_group_arn
 }
 
+output "default_mysql_parameter_group_id" {
+  description = "The db parameter group id"
+  value       = module.default_mysql.this_db_parameter_group_id
+}
+
+output "default_mysql_parameter_group_arn" {
+  description = "The ARN of the db parameter group"
+  value       = module.default_mysql.this_db_parameter_group_arn
+}
+
 # Default MySQL name
 output "default_mysql_name_option_group_id" {
   description = "The ID of the default MySQL option group using `name`"
@@ -31,6 +51,16 @@ output "default_mysql_name_option_group_arn" {
   value       = module.default_mysql_name.this_db_option_group_arn
 }
 
+output "default_mysql_name_parameter_group_id" {
+  description = "The db parameter group id"
+  value       = module.default_mysql_name.this_db_parameter_group_id
+}
+
+output "default_mysql_name_parameter_group_arn" {
+  description = "The ARN of the db parameter group"
+  value       = module.default_mysql_name.this_db_parameter_group_arn
+}
+
 # BYO MySQL
 output "byo_mysql_option_group_id" {
   description = "The ID of the BYO MySQL option group (should be blank)"
@@ -42,3 +72,12 @@ output "byo_mysql_option_group_arn" {
   value       = module.byo_mysql.this_db_option_group_arn
 }
 
+output "byo_mysql_parameter_group_id" {
+  description = "The db parameter group id"
+  value       = module.byo_mysql.this_db_parameter_group_id
+}
+
+output "byo_mysql_parameter_group_arn" {
+  description = "The ARN of the db parameter group"
+  value       = module.byo_mysql.this_db_parameter_group_arn
+}

examples/option-groups/variables.tf renamed to examples/groups/variables.tf

@@ -1,17 +1,17 @@
 locals {
-  enable_create_db_subnet_group = var.db_subnet_group_name == "" ? var.create_db_subnet_group : false
-  db_subnet_group_name          = coalesce(var.db_subnet_group_name, module.db_subnet_group.this_db_subnet_group_id)
+  create_db_subnet_group = var.db_subnet_group_name == "" ? var.create_db_subnet_group : false
+  db_subnet_group_name   = coalesce(var.db_subnet_group_name, module.db_subnet_group.this_db_subnet_group_id)
 
   parameter_group_name_id = coalesce(var.parameter_group_name, module.db_parameter_group.this_db_parameter_group_id)
 
-  enable_create_db_option_group = var.create_db_option_group && var.engine != "postgres"
-  option_group                  = var.engine != "postgres" ? coalesce(module.db_option_group.this_db_option_group_id, var.option_group_name) : null
+  create_db_option_group = var.create_db_option_group && var.engine != "postgres"
+  option_group           = var.engine != "postgres" ? coalesce(module.db_option_group.this_db_option_group_id, var.option_group_name) : null
 }
 
 module "db_subnet_group" {
   source = "./modules/db_subnet_group"
 
-  create      = local.enable_create_db_subnet_group
+  create      = local.create_db_subnet_group
   identifier  = var.identifier
   name_prefix = "${var.identifier}-"
   subnet_ids  = var.subnet_ids
@@ -22,25 +22,22 @@ module "db_subnet_group" {
 module "db_parameter_group" {
   source = "./modules/db_parameter_group"
 
-  create          = var.create_db_parameter_group
-  identifier      = var.identifier
+  create = var.create_db_parameter_group
+
   name            = var.parameter_group_name
+  use_name_prefix = var.parameter_group_use_name_prefix
   description     = var.parameter_group_description
-  name_prefix     = "${var.identifier}-"
-  use_name_prefix = var.use_parameter_group_name_prefix
   family          = var.family
 
   parameters = var.parameters
 
   tags = var.tags
 }
 
-# "${var.identifier}-${var.engine}-${var.major_engine_version}"
-
 module "db_option_group" {
   source = "./modules/db_option_group"
 
-  create = local.enable_create_db_option_group
+  create = local.create_db_option_group
 
   name                     = var.option_group_name
   use_name_prefix          = var.option_group_use_name_prefix

examples/option-groups/versions.tf renamed to examples/groups/versions.tf

@@ -31,12 +31,10 @@ No Modules.
 | create | Whether to create this resource or not? | `bool` | `true` | no |
 | description | The description of the DB parameter group | `string` | `""` | no |
 | family | The family of the DB parameter group | `string` | n/a | yes |
-| identifier | The identifier of the resource | `string` | n/a | yes |
 | name | The name of the DB parameter group | `string` | `""` | no |
-| name\_prefix | Creates a unique name beginning with the specified prefix | `string` | `""` | no |
 | parameters | A list of DB parameter maps to apply | `list(map(string))` | `[]` | no |
 | tags | A mapping of tags to assign to the resource | `map(string)` | `{}` | no |
-| use\_name\_prefix | Whether to use name\_prefix or not | `bool` | `true` | no |
+| use\_name\_prefix | Determines whether to use `name` as is or create a unique name beginning with `name` as the specified prefix | `bool` | `true` | no |
 
 ## Outputs
 

main.tf

@@ -1,39 +1,15 @@
 locals {
-  description = coalesce(var.description, "Database parameter group for ${var.identifier}")
-}
-
-resource "aws_db_parameter_group" "this_no_prefix" {
-  count = var.create && false == var.use_name_prefix ? 1 : 0
-
-  name        = var.name
-  description = local.description
-  family      = var.family
+  name        = var.use_name_prefix ? null : var.name
+  name_prefix = var.use_name_prefix ? "${var.name}-" : null
 
-  dynamic "parameter" {
-    for_each = var.parameters
-    content {
-      name         = parameter.value.name
-      value        = parameter.value.value
-      apply_method = lookup(parameter.value, "apply_method", null)
-    }
-  }
-
-  tags = merge(
-    var.tags,
-    {
-      "Name" = format("%s", var.name)
-    },
-  )
-
-  lifecycle {
-    create_before_destroy = true
-  }
+  description = coalesce(var.description, format("%s parameter group", var.name))
 }
 
 resource "aws_db_parameter_group" "this" {
-  count = var.create && var.use_name_prefix ? 1 : 0
+  count = var.create ? 1 : 0
 
-  name_prefix = var.name_prefix
+  name        = local.name
+  name_prefix = local.name_prefix
   description = local.description
   family      = var.family
 
@@ -49,7 +25,7 @@ resource "aws_db_parameter_group" "this" {
   tags = merge(
     var.tags,
     {
-      "Name" = format("%s", var.identifier)
+      "Name" = var.name
     },
   )
 

modules/db_parameter_group/README.md

@@ -1,10 +1,9 @@
 output "this_db_parameter_group_id" {
   description = "The db parameter group id"
-  value       = element(concat(aws_db_parameter_group.this.*.id, aws_db_parameter_group.this_no_prefix.*.id, [""]), 0)
+  value       = element(concat(aws_db_parameter_group.this.*.id, [""]), 0)
 }
 
 output "this_db_parameter_group_arn" {
   description = "The ARN of the db parameter group"
-  value       = element(concat(aws_db_parameter_group.this.*.arn, aws_db_parameter_group.this_no_prefix.*.arn, [""]), 0)
+  value       = element(concat(aws_db_parameter_group.this.*.arn, [""]), 0)
 }
-