fix: add default values to allow for completely disabling module with bare minimum input (#342)

.pre-commit-config.yaml

@@ -21,6 +21,6 @@ repos:
           - '--args=--only=terraform_standard_module_structure'
           - '--args=--only=terraform_workspace_remote'
   - repo: git://github.com/pre-commit/pre-commit-hooks
-    rev: v3.4.0
+    rev: v4.0.1
     hooks:
       - id: check-merge-conflict

README.md

@@ -235,13 +235,13 @@ Users have the ability to:
 
 | Name | Description | Type | Default | Required |
 |------|-------------|------|---------|:--------:|
-| <a name="input_allocated_storage"></a> [allocated\_storage](#input\_allocated\_storage) | The allocated storage in gigabytes | `string` | n/a | yes |
+| <a name="input_allocated_storage"></a> [allocated\_storage](#input\_allocated\_storage) | The allocated storage in gigabytes | `string` | `null` | no |
 | <a name="input_allow_major_version_upgrade"></a> [allow\_major\_version\_upgrade](#input\_allow\_major\_version\_upgrade) | Indicates that major version upgrades are allowed. Changing this parameter does not result in an outage and the change is asynchronously applied as soon as possible | `bool` | `false` | no |
 | <a name="input_apply_immediately"></a> [apply\_immediately](#input\_apply\_immediately) | Specifies whether any database modifications are applied immediately, or during the next maintenance window | `bool` | `false` | no |
 | <a name="input_auto_minor_version_upgrade"></a> [auto\_minor\_version\_upgrade](#input\_auto\_minor\_version\_upgrade) | Indicates that minor engine upgrades will be applied automatically to the DB instance during the maintenance window | `bool` | `true` | no |
 | <a name="input_availability_zone"></a> [availability\_zone](#input\_availability\_zone) | The Availability Zone of the RDS instance | `string` | `null` | no |
 | <a name="input_backup_retention_period"></a> [backup\_retention\_period](#input\_backup\_retention\_period) | The days to retain backups for | `number` | `null` | no |
-| <a name="input_backup_window"></a> [backup\_window](#input\_backup\_window) | The daily time range (in UTC) during which automated backups are created if they are enabled. Example: '09:46-10:16'. Must not overlap with maintenance\_window | `string` | n/a | yes |
+| <a name="input_backup_window"></a> [backup\_window](#input\_backup\_window) | The daily time range (in UTC) during which automated backups are created if they are enabled. Example: '09:46-10:16'. Must not overlap with maintenance\_window | `string` | `null` | no |
 | <a name="input_ca_cert_identifier"></a> [ca\_cert\_identifier](#input\_ca\_cert\_identifier) | Specifies the identifier of the CA certificate for the DB instance | `string` | `null` | no |
 | <a name="input_character_set_name"></a> [character\_set\_name](#input\_character\_set\_name) | (Optional) The character set name to use for DB encoding in Oracle instances. This can't be changed. See Oracle Character Sets Supported in Amazon RDS and Collations and Character Sets for Microsoft SQL Server for more information. This can only be set on creation. | `string` | `null` | no |
 | <a name="input_copy_tags_to_snapshot"></a> [copy\_tags\_to\_snapshot](#input\_copy\_tags\_to\_snapshot) | On delete, copy all Instance tags to the final snapshot (if final\_snapshot\_identifier is specified) | `bool` | `false` | no |
@@ -263,18 +263,18 @@ Users have the ability to:
 | <a name="input_domain"></a> [domain](#input\_domain) | The ID of the Directory Service Active Directory domain to create the instance in | `string` | `null` | no |
 | <a name="input_domain_iam_role_name"></a> [domain\_iam\_role\_name](#input\_domain\_iam\_role\_name) | (Required if domain is provided) The name of the IAM role to be used when making API calls to the Directory Service | `string` | `null` | no |
 | <a name="input_enabled_cloudwatch_logs_exports"></a> [enabled\_cloudwatch\_logs\_exports](#input\_enabled\_cloudwatch\_logs\_exports) | List of log types to enable for exporting to CloudWatch logs. If omitted, no logs will be exported. Valid values (depending on engine): alert, audit, error, general, listener, slowquery, trace, postgresql (PostgreSQL), upgrade (PostgreSQL). | `list(string)` | `[]` | no |
-| <a name="input_engine"></a> [engine](#input\_engine) | The database engine to use | `string` | n/a | yes |
-| <a name="input_engine_version"></a> [engine\_version](#input\_engine\_version) | The engine version to use | `string` | n/a | yes |
+| <a name="input_engine"></a> [engine](#input\_engine) | The database engine to use | `string` | `""` | no |
+| <a name="input_engine_version"></a> [engine\_version](#input\_engine\_version) | The engine version to use | `string` | `null` | no |
 | <a name="input_family"></a> [family](#input\_family) | The family of the DB parameter group | `string` | `""` | no |
 | <a name="input_final_snapshot_identifier"></a> [final\_snapshot\_identifier](#input\_final\_snapshot\_identifier) | The name of your final DB snapshot when this DB instance is deleted. | `string` | `null` | no |
 | <a name="input_final_snapshot_identifier_prefix"></a> [final\_snapshot\_identifier\_prefix](#input\_final\_snapshot\_identifier\_prefix) | The name which is prefixed to the final snapshot on cluster destroy | `string` | `"final"` | no |
 | <a name="input_iam_database_authentication_enabled"></a> [iam\_database\_authentication\_enabled](#input\_iam\_database\_authentication\_enabled) | Specifies whether or not the mappings of AWS Identity and Access Management (IAM) accounts to database accounts are enabled | `bool` | `false` | no |
 | <a name="input_identifier"></a> [identifier](#input\_identifier) | The name of the RDS instance, if omitted, Terraform will assign a random, unique identifier | `string` | n/a | yes |
-| <a name="input_instance_class"></a> [instance\_class](#input\_instance\_class) | The instance type of the RDS instance | `string` | n/a | yes |
+| <a name="input_instance_class"></a> [instance\_class](#input\_instance\_class) | The instance type of the RDS instance | `string` | `null` | no |
 | <a name="input_iops"></a> [iops](#input\_iops) | The amount of provisioned IOPS. Setting this implies a storage\_type of 'io1' | `number` | `0` | no |
 | <a name="input_kms_key_id"></a> [kms\_key\_id](#input\_kms\_key\_id) | The ARN for the KMS encryption key. If creating an encrypted replica, set this to the destination KMS ARN. If storage\_encrypted is set to true and kms\_key\_id is not specified the default KMS key created in your account will be used | `string` | `null` | no |
 | <a name="input_license_model"></a> [license\_model](#input\_license\_model) | License model information for this DB instance. Optional, but required for some DB engines, i.e. Oracle SE1 | `string` | `null` | no |
-| <a name="input_maintenance_window"></a> [maintenance\_window](#input\_maintenance\_window) | The window to perform maintenance in. Syntax: 'ddd:hh24:mi-ddd:hh24:mi'. Eg: 'Mon:00:00-Mon:03:00' | `string` | n/a | yes |
+| <a name="input_maintenance_window"></a> [maintenance\_window](#input\_maintenance\_window) | The window to perform maintenance in. Syntax: 'ddd:hh24:mi-ddd:hh24:mi'. Eg: 'Mon:00:00-Mon:03:00' | `string` | `null` | no |
 | <a name="input_major_engine_version"></a> [major\_engine\_version](#input\_major\_engine\_version) | Specifies the major version of the engine that this option group should be associated with | `string` | `""` | no |
 | <a name="input_max_allocated_storage"></a> [max\_allocated\_storage](#input\_max\_allocated\_storage) | Specifies the value for Storage Autoscaling | `number` | `0` | no |
 | <a name="input_monitoring_interval"></a> [monitoring\_interval](#input\_monitoring\_interval) | The interval, in seconds, between points when Enhanced Monitoring metrics are collected for the DB instance. To disable collecting Enhanced Monitoring metrics, specify 0. The default is 0. Valid Values: 0, 1, 5, 10, 15, 30, 60. | `number` | `0` | no |
@@ -295,7 +295,7 @@ Users have the ability to:
 | <a name="input_performance_insights_enabled"></a> [performance\_insights\_enabled](#input\_performance\_insights\_enabled) | Specifies whether Performance Insights are enabled | `bool` | `false` | no |
 | <a name="input_performance_insights_kms_key_id"></a> [performance\_insights\_kms\_key\_id](#input\_performance\_insights\_kms\_key\_id) | The ARN for the KMS key to encrypt Performance Insights data. | `string` | `null` | no |
 | <a name="input_performance_insights_retention_period"></a> [performance\_insights\_retention\_period](#input\_performance\_insights\_retention\_period) | The amount of time in days to retain Performance Insights data. Either 7 (7 days) or 731 (2 years). | `number` | `7` | no |
-| <a name="input_port"></a> [port](#input\_port) | The port on which the DB accepts connections | `string` | n/a | yes |
+| <a name="input_port"></a> [port](#input\_port) | The port on which the DB accepts connections | `string` | `null` | no |
 | <a name="input_publicly_accessible"></a> [publicly\_accessible](#input\_publicly\_accessible) | Bool to control if instance is publicly accessible | `bool` | `false` | no |
 | <a name="input_random_password_length"></a> [random\_password\_length](#input\_random\_password\_length) | (Optional) Length of random password to create. (default: 10) | `number` | `10` | no |
 | <a name="input_replicate_source_db"></a> [replicate\_source\_db](#input\_replicate\_source\_db) | Specifies that this resource is a Replicate database, and to use this value as the source database. This correlates to the identifier of another Amazon RDS Database to replicate. | `string` | `null` | no |
@@ -308,7 +308,7 @@ Users have the ability to:
 | <a name="input_tags"></a> [tags](#input\_tags) | A mapping of tags to assign to all resources | `map(string)` | `{}` | no |
 | <a name="input_timeouts"></a> [timeouts](#input\_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 |
 | <a name="input_timezone"></a> [timezone](#input\_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` | `null` | no |
-| <a name="input_username"></a> [username](#input\_username) | Username for the master DB user | `string` | n/a | yes |
+| <a name="input_username"></a> [username](#input\_username) | Username for the master DB user | `string` | `null` | no |
 | <a name="input_vpc_security_group_ids"></a> [vpc\_security\_group\_ids](#input\_vpc\_security\_group\_ids) | List of VPC security groups to associate | `list(string)` | `[]` | no |
 
 ## Outputs

examples/complete-mssql/README.md

@@ -33,6 +33,7 @@ Note that this example may create resources which cost money. Run `terraform des
 | Name | Source | Version |
 |------|--------|---------|
 | <a name="module_db"></a> [db](#module\_db) | ../../ |  |
+| <a name="module_db_disabled"></a> [db\_disabled](#module\_db\_disabled) | ../../ |  |
 | <a name="module_security_group"></a> [security\_group](#module\_security\_group) | terraform-aws-modules/security-group/aws | ~> 4 |
 | <a name="module_vpc"></a> [vpc](#module\_vpc) | terraform-aws-modules/vpc/aws | ~> 2 |
 

examples/complete-mssql/main.tf

@@ -159,3 +159,14 @@ module "db" {
 
   tags = local.tags
 }
+
+module "db_disabled" {
+  source = "../../"
+
+  identifier = "${local.name}-disabled"
+
+  create_db_instance        = false
+  create_db_subnet_group    = false
+  create_db_parameter_group = false
+  create_db_option_group    = false
+}

examples/complete-mysql/README.md

@@ -32,6 +32,7 @@ No providers.
 |------|--------|---------|
 | <a name="module_db"></a> [db](#module\_db) | ../../ |  |
 | <a name="module_db_default"></a> [db\_default](#module\_db\_default) | ../../ |  |
+| <a name="module_db_disabled"></a> [db\_disabled](#module\_db\_disabled) | ../../ |  |
 | <a name="module_security_group"></a> [security\_group](#module\_security\_group) | terraform-aws-modules/security-group/aws | ~> 4 |
 | <a name="module_vpc"></a> [vpc](#module\_vpc) | terraform-aws-modules/vpc/aws | ~> 2 |
 

examples/complete-mysql/main.tf

@@ -155,3 +155,14 @@ module "db_default" {
 
   tags = local.tags
 }
+
+module "db_disabled" {
+  source = "../../"
+
+  identifier = "${local.name}-disabled"
+
+  create_db_instance        = false
+  create_db_subnet_group    = false
+  create_db_parameter_group = false
+  create_db_option_group    = false
+}

examples/complete-oracle/README.md

@@ -31,6 +31,7 @@ No providers.
 | Name | Source | Version |
 |------|--------|---------|
 | <a name="module_db"></a> [db](#module\_db) | ../../ |  |
+| <a name="module_db_disabled"></a> [db\_disabled](#module\_db\_disabled) | ../../ |  |
 | <a name="module_security_group"></a> [security\_group](#module\_security\_group) | terraform-aws-modules/security-group/aws | ~> 4 |
 | <a name="module_vpc"></a> [vpc](#module\_vpc) | terraform-aws-modules/vpc/aws | ~> 2 |
 

examples/complete-oracle/main.tf

@@ -102,3 +102,14 @@ module "db" {
 
   tags = local.tags
 }
+
+module "db_disabled" {
+  source = "../../"
+
+  identifier = "${local.name}-disabled"
+
+  create_db_instance        = false
+  create_db_subnet_group    = false
+  create_db_parameter_group = false
+  create_db_option_group    = false
+}

examples/complete-postgres/README.md

@@ -32,6 +32,7 @@ No providers.
 |------|--------|---------|
 | <a name="module_db"></a> [db](#module\_db) | ../../ |  |
 | <a name="module_db_default"></a> [db\_default](#module\_db\_default) | ../../ |  |
+| <a name="module_db_disabled"></a> [db\_disabled](#module\_db\_disabled) | ../../ |  |
 | <a name="module_security_group"></a> [security\_group](#module\_security\_group) | terraform-aws-modules/security-group/aws | ~> 4 |
 | <a name="module_vpc"></a> [vpc](#module\_vpc) | terraform-aws-modules/vpc/aws | ~> 2 |
 

examples/complete-postgres/main.tf

@@ -159,3 +159,14 @@ module "db_default" {
 
   tags = local.tags
 }
+
+module "db_disabled" {
+  source = "../../"
+
+  identifier = "${local.name}-disabled"
+
+  create_db_instance        = false
+  create_db_subnet_group    = false
+  create_db_parameter_group = false
+  create_db_option_group    = false
+}

main.tf

 locals {
   master_password      = var.create_db_instance && var.create_random_password ? random_password.master_password[0].result : var.password
-  db_subnet_group_name = var.replicate_source_db != null ? null : coalesce(var.db_subnet_group_name, module.db_subnet_group.db_subnet_group_id)
+  db_subnet_group_name = var.replicate_source_db != null ? null : coalesce(var.db_subnet_group_name, module.db_subnet_group.db_subnet_group_id, var.identifier)
 
   parameter_group_name_id = var.create_db_parameter_group ? module.db_parameter_group.db_parameter_group_id : var.parameter_group_name
 

modules/db_instance/README.md

@@ -36,13 +36,13 @@ No modules.
 
 | Name | Description | Type | Default | Required |
 |------|-------------|------|---------|:--------:|
-| <a name="input_allocated_storage"></a> [allocated\_storage](#input\_allocated\_storage) | The allocated storage in gigabytes | `string` | n/a | yes |
+| <a name="input_allocated_storage"></a> [allocated\_storage](#input\_allocated\_storage) | The allocated storage in gigabytes | `string` | `null` | no |
 | <a name="input_allow_major_version_upgrade"></a> [allow\_major\_version\_upgrade](#input\_allow\_major\_version\_upgrade) | Indicates that major version upgrades are allowed. Changing this parameter does not result in an outage and the change is asynchronously applied as soon as possible | `bool` | `false` | no |
 | <a name="input_apply_immediately"></a> [apply\_immediately](#input\_apply\_immediately) | Specifies whether any database modifications are applied immediately, or during the next maintenance window | `bool` | `false` | no |
 | <a name="input_auto_minor_version_upgrade"></a> [auto\_minor\_version\_upgrade](#input\_auto\_minor\_version\_upgrade) | Indicates that minor engine upgrades will be applied automatically to the DB instance during the maintenance window | `bool` | `true` | no |
 | <a name="input_availability_zone"></a> [availability\_zone](#input\_availability\_zone) | The Availability Zone of the RDS instance | `string` | `null` | no |
 | <a name="input_backup_retention_period"></a> [backup\_retention\_period](#input\_backup\_retention\_period) | The days to retain backups for | `number` | `null` | no |
-| <a name="input_backup_window"></a> [backup\_window](#input\_backup\_window) | The daily time range (in UTC) during which automated backups are created if they are enabled. Example: '09:46-10:16'. Must not overlap with maintenance\_window | `string` | n/a | yes |
+| <a name="input_backup_window"></a> [backup\_window](#input\_backup\_window) | The daily time range (in UTC) during which automated backups are created if they are enabled. Example: '09:46-10:16'. Must not overlap with maintenance\_window | `string` | `null` | no |
 | <a name="input_ca_cert_identifier"></a> [ca\_cert\_identifier](#input\_ca\_cert\_identifier) | Specifies the identifier of the CA certificate for the DB instance | `string` | `null` | no |
 | <a name="input_character_set_name"></a> [character\_set\_name](#input\_character\_set\_name) | (Optional) The character set name to use for DB encoding in Oracle instances. This can't be changed. See Oracle Character Sets Supported in Amazon RDS and Collations and Character Sets for Microsoft SQL Server for more information. This can only be set on creation. | `string` | `null` | no |
 | <a name="input_copy_tags_to_snapshot"></a> [copy\_tags\_to\_snapshot](#input\_copy\_tags\_to\_snapshot) | On delete, copy all Instance tags to the final snapshot (if final\_snapshot\_identifier is specified) | `bool` | `false` | no |
@@ -54,17 +54,17 @@ No modules.
 | <a name="input_domain"></a> [domain](#input\_domain) | The ID of the Directory Service Active Directory domain to create the instance in | `string` | `null` | no |
 | <a name="input_domain_iam_role_name"></a> [domain\_iam\_role\_name](#input\_domain\_iam\_role\_name) | (Required if domain is provided) The name of the IAM role to be used when making API calls to the Directory Service | `string` | `null` | no |
 | <a name="input_enabled_cloudwatch_logs_exports"></a> [enabled\_cloudwatch\_logs\_exports](#input\_enabled\_cloudwatch\_logs\_exports) | List of log types to enable for exporting to CloudWatch logs. If omitted, no logs will be exported. Valid values (depending on engine): alert, audit, error, general, listener, slowquery, trace, postgresql (PostgreSQL), upgrade (PostgreSQL). | `list(string)` | `[]` | no |
-| <a name="input_engine"></a> [engine](#input\_engine) | The database engine to use | `string` | n/a | yes |
-| <a name="input_engine_version"></a> [engine\_version](#input\_engine\_version) | The engine version to use | `string` | n/a | yes |
+| <a name="input_engine"></a> [engine](#input\_engine) | The database engine to use | `string` | `""` | no |
+| <a name="input_engine_version"></a> [engine\_version](#input\_engine\_version) | The engine version to use | `string` | `null` | no |
 | <a name="input_final_snapshot_identifier"></a> [final\_snapshot\_identifier](#input\_final\_snapshot\_identifier) | The name of your final DB snapshot when this DB instance is deleted. | `string` | `null` | no |
 | <a name="input_final_snapshot_identifier_prefix"></a> [final\_snapshot\_identifier\_prefix](#input\_final\_snapshot\_identifier\_prefix) | The name which is prefixed to the final snapshot on cluster destroy | `string` | `"final"` | no |
 | <a name="input_iam_database_authentication_enabled"></a> [iam\_database\_authentication\_enabled](#input\_iam\_database\_authentication\_enabled) | Specifies whether or mappings of AWS Identity and Access Management (IAM) accounts to database accounts is enabled | `bool` | `false` | no |
 | <a name="input_identifier"></a> [identifier](#input\_identifier) | The name of the RDS instance, if omitted, Terraform will assign a random, unique identifier | `string` | n/a | yes |
-| <a name="input_instance_class"></a> [instance\_class](#input\_instance\_class) | The instance type of the RDS instance | `string` | n/a | yes |
+| <a name="input_instance_class"></a> [instance\_class](#input\_instance\_class) | The instance type of the RDS instance | `string` | `null` | no |
 | <a name="input_iops"></a> [iops](#input\_iops) | The amount of provisioned IOPS. Setting this implies a storage\_type of 'io1' | `number` | `0` | no |
 | <a name="input_kms_key_id"></a> [kms\_key\_id](#input\_kms\_key\_id) | The ARN for the KMS encryption key. If creating an encrypted replica, set this to the destination KMS ARN. If storage\_encrypted is set to true and kms\_key\_id is not specified the default KMS key created in your account will be used | `string` | `null` | no |
 | <a name="input_license_model"></a> [license\_model](#input\_license\_model) | License model information for this DB instance. Optional, but required for some DB engines, i.e. Oracle SE1 | `string` | `null` | no |
-| <a name="input_maintenance_window"></a> [maintenance\_window](#input\_maintenance\_window) | The window to perform maintenance in. Syntax: 'ddd:hh24:mi-ddd:hh24:mi'. Eg: 'Mon:00:00-Mon:03:00' | `string` | n/a | yes |
+| <a name="input_maintenance_window"></a> [maintenance\_window](#input\_maintenance\_window) | The window to perform maintenance in. Syntax: 'ddd:hh24:mi-ddd:hh24:mi'. Eg: 'Mon:00:00-Mon:03:00' | `string` | `null` | no |
 | <a name="input_max_allocated_storage"></a> [max\_allocated\_storage](#input\_max\_allocated\_storage) | Specifies the value for Storage Autoscaling | `number` | `0` | no |
 | <a name="input_monitoring_interval"></a> [monitoring\_interval](#input\_monitoring\_interval) | The interval, in seconds, between points when Enhanced Monitoring metrics are collected for the DB instance. To disable collecting Enhanced Monitoring metrics, specify 0. The default is 0. Valid Values: 0, 1, 5, 10, 15, 30, 60. | `number` | `0` | no |
 | <a name="input_monitoring_role_arn"></a> [monitoring\_role\_arn](#input\_monitoring\_role\_arn) | The ARN for the IAM role that permits RDS to send enhanced monitoring metrics to CloudWatch Logs. Must be specified if monitoring\_interval is non-zero. | `string` | `null` | no |
@@ -73,11 +73,11 @@ No modules.
 | <a name="input_name"></a> [name](#input\_name) | The DB name to create. If omitted, no database is created initially | `string` | `null` | no |
 | <a name="input_option_group_name"></a> [option\_group\_name](#input\_option\_group\_name) | Name of the DB option group to associate. | `string` | `""` | no |
 | <a name="input_parameter_group_name"></a> [parameter\_group\_name](#input\_parameter\_group\_name) | Name of the DB parameter group to associate | `string` | `""` | no |
-| <a name="input_password"></a> [password](#input\_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 |
+| <a name="input_password"></a> [password](#input\_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` | `null` | no |
 | <a name="input_performance_insights_enabled"></a> [performance\_insights\_enabled](#input\_performance\_insights\_enabled) | Specifies whether Performance Insights are enabled | `bool` | `false` | no |
 | <a name="input_performance_insights_kms_key_id"></a> [performance\_insights\_kms\_key\_id](#input\_performance\_insights\_kms\_key\_id) | The ARN for the KMS key to encrypt Performance Insights data. | `string` | `null` | no |
 | <a name="input_performance_insights_retention_period"></a> [performance\_insights\_retention\_period](#input\_performance\_insights\_retention\_period) | The amount of time in days to retain Performance Insights data. Either 7 (7 days) or 731 (2 years). | `number` | `7` | no |
-| <a name="input_port"></a> [port](#input\_port) | The port on which the DB accepts connections | `string` | n/a | yes |
+| <a name="input_port"></a> [port](#input\_port) | The port on which the DB accepts connections | `string` | `null` | no |
 | <a name="input_publicly_accessible"></a> [publicly\_accessible](#input\_publicly\_accessible) | Bool to control if instance is publicly accessible | `bool` | `false` | no |
 | <a name="input_replicate_source_db"></a> [replicate\_source\_db](#input\_replicate\_source\_db) | Specifies that this resource is a Replicate database, and to use this value as the source database. This correlates to the identifier of another Amazon RDS Database to replicate. | `string` | `null` | no |
 | <a name="input_s3_import"></a> [s3\_import](#input\_s3\_import) | Restore from a Percona Xtrabackup in S3 (only MySQL is supported) | `map(string)` | `null` | no |
@@ -88,7 +88,7 @@ No modules.
 | <a name="input_tags"></a> [tags](#input\_tags) | A mapping of tags to assign to all resources | `map(string)` | `{}` | no |
 | <a name="input_timeouts"></a> [timeouts](#input\_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 |
 | <a name="input_timezone"></a> [timezone](#input\_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` | `null` | no |
-| <a name="input_username"></a> [username](#input\_username) | Username for the master DB user | `string` | n/a | yes |
+| <a name="input_username"></a> [username](#input\_username) | Username for the master DB user | `string` | `null` | no |
 | <a name="input_vpc_security_group_ids"></a> [vpc\_security\_group\_ids](#input\_vpc\_security\_group\_ids) | List of VPC security groups to associate | `list(string)` | `[]` | no |
 
 ## Outputs

modules/db_instance/variables.tf

@@ -12,6 +12,7 @@ variable "identifier" {
 variable "allocated_storage" {
   description = "The allocated storage in gigabytes"
   type        = string
+  default     = null
 }
 
 variable "storage_type" {
@@ -65,16 +66,19 @@ variable "domain_iam_role_name" {
 variable "engine" {
   description = "The database engine to use"
   type        = string
+  default     = ""
 }
 
 variable "engine_version" {
   description = "The engine version to use"
   type        = string
+  default     = null
 }
 
 variable "instance_class" {
   description = "The instance type of the RDS instance"
   type        = string
+  default     = null
 }
 
 variable "name" {
@@ -86,16 +90,19 @@ variable "name" {
 variable "username" {
   description = "Username for the master DB user"
   type        = string
+  default     = null
 }
 
 variable "password" {
   description = "Password for the master DB user. Note that this may show up in logs, and it will be stored in the state file"
   type        = string
+  default     = null
 }
 
 variable "port" {
   description = "The port on which the DB accepts connections"
   type        = string
+  default     = null
 }
 
 variable "skip_final_snapshot" {
@@ -215,6 +222,7 @@ variable "apply_immediately" {
 variable "maintenance_window" {
   description = "The window to perform maintenance in. Syntax: 'ddd:hh24:mi-ddd:hh24:mi'. Eg: 'Mon:00:00-Mon:03:00'"
   type        = string
+  default     = null
 }
 
 variable "backup_retention_period" {
@@ -226,6 +234,7 @@ variable "backup_retention_period" {
 variable "backup_window" {
   description = "The daily time range (in UTC) during which automated backups are created if they are enabled. Example: '09:46-10:16'. Must not overlap with maintenance_window"
   type        = string
+  default     = null
 }
 
 variable "tags" {

modules/db_option_group/README.md

@@ -29,8 +29,8 @@ No modules.
 | Name | Description | Type | Default | Required |
 |------|-------------|------|---------|:--------:|
 | <a name="input_create"></a> [create](#input\_create) | Whether to create this resource or not? | `bool` | `true` | no |
-| <a name="input_engine_name"></a> [engine\_name](#input\_engine\_name) | Specifies the name of the engine that this option group should be associated with | `string` | n/a | yes |
-| <a name="input_major_engine_version"></a> [major\_engine\_version](#input\_major\_engine\_version) | Specifies the major version of the engine that this option group should be associated with | `string` | n/a | yes |
+| <a name="input_engine_name"></a> [engine\_name](#input\_engine\_name) | Specifies the name of the engine that this option group should be associated with | `string` | `null` | no |
+| <a name="input_major_engine_version"></a> [major\_engine\_version](#input\_major\_engine\_version) | Specifies the major version of the engine that this option group should be associated with | `string` | `null` | no |
 | <a name="input_name"></a> [name](#input\_name) | The name of the option group | `string` | `""` | no |
 | <a name="input_option_group_description"></a> [option\_group\_description](#input\_option\_group\_description) | The description of the option group | `string` | `""` | no |
 | <a name="input_options"></a> [options](#input\_options) | A list of Options to apply | `any` | `[]` | no |

modules/db_option_group/variables.tf

@@ -25,11 +25,13 @@ variable "option_group_description" {
 variable "engine_name" {
   description = "Specifies the name of the engine that this option group should be associated with"
   type        = string
+  default     = null
 }
 
 variable "major_engine_version" {
   description = "Specifies the major version of the engine that this option group should be associated with"
   type        = string
+  default     = null
 }
 
 variable "options" {

modules/db_parameter_group/README.md

@@ -30,7 +30,7 @@ No modules.
 |------|-------------|------|---------|:--------:|
 | <a name="input_create"></a> [create](#input\_create) | Whether to create this resource or not? | `bool` | `true` | no |
 | <a name="input_description"></a> [description](#input\_description) | The description of the DB parameter group | `string` | `""` | no |
-| <a name="input_family"></a> [family](#input\_family) | The family of the DB parameter group | `string` | n/a | yes |
+| <a name="input_family"></a> [family](#input\_family) | The family of the DB parameter group | `string` | `null` | no |
 | <a name="input_name"></a> [name](#input\_name) | The name of the DB parameter group | `string` | `""` | no |
 | <a name="input_parameters"></a> [parameters](#input\_parameters) | A list of DB parameter maps to apply | `list(map(string))` | `[]` | no |
 | <a name="input_tags"></a> [tags](#input\_tags) | A mapping of tags to assign to the resource | `map(string)` | `{}` | no |

modules/db_parameter_group/variables.tf

@@ -25,6 +25,7 @@ variable "description" {
 variable "family" {
   description = "The family of the DB parameter group"
   type        = string
+  default     = null
 }
 
 variable "parameters" {

variables.tf

@@ -6,6 +6,7 @@ variable "identifier" {
 variable "allocated_storage" {
   description = "The allocated storage in gigabytes"
   type        = string
+  default     = null
 }
 
 variable "storage_type" {
@@ -59,11 +60,13 @@ variable "domain_iam_role_name" {
 variable "engine" {
   description = "The database engine to use"
   type        = string
+  default     = ""
 }
 
 variable "engine_version" {
   description = "The engine version to use"
   type        = string
+  default     = null
 }
 
 variable "skip_final_snapshot" {
@@ -99,6 +102,7 @@ variable "final_snapshot_identifier_prefix" {
 variable "instance_class" {
   description = "The instance type of the RDS instance"
   type        = string
+  default     = null
 }
 
 variable "name" {
@@ -110,6 +114,7 @@ variable "name" {
 variable "username" {
   description = "Username for the master DB user"
   type        = string
+  default     = null
 }
 
 variable "password" {
@@ -121,6 +126,7 @@ variable "password" {
 variable "port" {
   description = "The port on which the DB accepts connections"
   type        = string
+  default     = null
 }
 
 variable "vpc_security_group_ids" {
@@ -198,6 +204,7 @@ variable "apply_immediately" {
 variable "maintenance_window" {
   description = "The window to perform maintenance in. Syntax: 'ddd:hh24:mi-ddd:hh24:mi'. Eg: 'Mon:00:00-Mon:03:00'"
   type        = string
+  default     = null
 }
 
 variable "backup_retention_period" {
@@ -209,6 +216,7 @@ variable "backup_retention_period" {
 variable "backup_window" {
   description = "The daily time range (in UTC) during which automated backups are created if they are enabled. Example: '09:46-10:16'. Must not overlap with maintenance_window"
   type        = string
+  default     = null
 }
 
 variable "s3_import" {