Make certain arguments optional to allow creation of replicas (#136)

* fixed replica db creation

* Auto Format

* Update main.tf

Co-authored-by: nitrocode <[email protected]>

* edited variable descriptions

* Auto Format

* Update main.tf

Co-authored-by: nitrocode <[email protected]>

* Apply suggestions from code review

Co-authored-by: nitrocode <[email protected]>

* Auto Format

* more fixes

* Auto Format

* description improvements

* formatting

* Auto Format

Co-authored-by: cloudpossebot <[email protected]>
Co-authored-by: nitrocode <[email protected]>
Co-authored-by: nitrocode <[email protected]>

Author: 3 people

README.md

@@ -253,7 +253,7 @@ Available targets:
 | Name | Description | Type | Default | Required |
 |------|-------------|------|---------|:--------:|
 | <a name="input_additional_tag_map"></a> [additional\_tag\_map](#input\_additional\_tag\_map) | Additional key-value pairs to add to each map in `tags_as_list_of_maps`. Not added to `tags` or `id`.<br>This is for some rare cases where resources want additional configuration of tags<br>and therefore take a list of maps with tag key, value, and additional configuration. | `map(string)` | `{}` | no |
-| <a name="input_allocated_storage"></a> [allocated\_storage](#input\_allocated\_storage) | The allocated storage in GBs | `number` | `null` | no |
+| <a name="input_allocated_storage"></a> [allocated\_storage](#input\_allocated\_storage) | The allocated storage in GBs. Required unless a `snapshot_identifier` or `replicate_source_db` is provided. | `number` | `null` | no |
 | <a name="input_allow_major_version_upgrade"></a> [allow\_major\_version\_upgrade](#input\_allow\_major\_version\_upgrade) | Allow major version upgrade | `bool` | `false` | no |
 | <a name="input_allowed_cidr_blocks"></a> [allowed\_cidr\_blocks](#input\_allowed\_cidr\_blocks) | The whitelisted CIDRs which to allow `ingress` traffic to the DB instance | `list(string)` | `[]` | 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 |
@@ -267,10 +267,10 @@ Available targets:
 | <a name="input_charset_name"></a> [charset\_name](#input\_charset\_name) | The character set name to use for DB encoding. [Oracle & Microsoft SQL only](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/db_instance#character_set_name). For other engines use `db_parameter` | `string` | `null` | no |
 | <a name="input_context"></a> [context](#input\_context) | Single object for setting entire context at once.<br>See description of individual variables for details.<br>Leave string and numeric variables as `null` to use default value.<br>Individual variable settings (non-null) override settings in context object,<br>except for attributes, tags, and additional\_tag\_map, which are merged. | `any` | <pre>{<br>  "additional_tag_map": {},<br>  "attributes": [],<br>  "delimiter": null,<br>  "descriptor_formats": {},<br>  "enabled": true,<br>  "environment": null,<br>  "id_length_limit": null,<br>  "label_key_case": null,<br>  "label_order": [],<br>  "label_value_case": null,<br>  "labels_as_tags": [<br>    "unset"<br>  ],<br>  "name": null,<br>  "namespace": null,<br>  "regex_replace_chars": null,<br>  "stage": null,<br>  "tags": {},<br>  "tenant": null<br>}</pre> | no |
 | <a name="input_copy_tags_to_snapshot"></a> [copy\_tags\_to\_snapshot](#input\_copy\_tags\_to\_snapshot) | Copy tags from DB to a snapshot | `bool` | `true` | no |
-| <a name="input_database_name"></a> [database\_name](#input\_database\_name) | The name of the database to create when the DB instance is created | `string` | n/a | yes |
-| <a name="input_database_password"></a> [database\_password](#input\_database\_password) | (Required unless a snapshot\_identifier or replicate\_source\_db is provided) Password for the master DB user | `string` | `""` | no |
+| <a name="input_database_name"></a> [database\_name](#input\_database\_name) | The name of the database to create when the DB instance is created | `string` | `null` | no |
+| <a name="input_database_password"></a> [database\_password](#input\_database\_password) | Password for the primary DB user. Required unless a `snapshot_identifier` or `replicate_source_db` is provided. | `string` | `null` | no |
 | <a name="input_database_port"></a> [database\_port](#input\_database\_port) | Database port (\_e.g.\_ `3306` for `MySQL`). Used in the DB Security Group to allow access to the DB instance from the provided `security_group_ids` | `number` | n/a | yes |
-| <a name="input_database_user"></a> [database\_user](#input\_database\_user) | (Required unless a `snapshot_identifier` or `replicate_source_db` is provided) Username for the master DB user | `string` | `""` | no |
+| <a name="input_database_user"></a> [database\_user](#input\_database\_user) | Username for the primary DB user. Required unless a `snapshot_identifier` or `replicate_source_db` is provided. | `string` | `null` | no |
 | <a name="input_db_options"></a> [db\_options](#input\_db\_options) | A list of DB options to apply with an option group. Depends on DB engine | <pre>list(object({<br>    db_security_group_memberships  = list(string)<br>    option_name                    = string<br>    port                           = number<br>    version                        = string<br>    vpc_security_group_memberships = list(string)<br><br>    option_settings = list(object({<br>      name  = string<br>      value = string<br>    }))<br>  }))</pre> | `[]` | no |
 | <a name="input_db_parameter"></a> [db\_parameter](#input\_db\_parameter) | A list of DB parameters to apply. Note that parameters may differ from a DB family to another | <pre>list(object({<br>    apply_method = string<br>    name         = string<br>    value        = string<br>  }))</pre> | `[]` | no |
 | <a name="input_db_parameter_group"></a> [db\_parameter\_group](#input\_db\_parameter\_group) | The DB parameter group family name. The value depends on DB engine used. See [DBParameterGroupFamily](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBParameterGroup.html#API_CreateDBParameterGroup_RequestParameters) for instructions on how to retrieve applicable value. | `string` | n/a | yes |
@@ -281,8 +281,8 @@ Available targets:
 | <a name="input_dns_zone_id"></a> [dns\_zone\_id](#input\_dns\_zone\_id) | The ID of the DNS Zone in Route53 where a new DNS record will be created for the DB host name | `string` | `""` | no |
 | <a name="input_enabled"></a> [enabled](#input\_enabled) | Set to false to prevent the module from creating any resources | `bool` | `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) | Database engine type | `string` | `null` | no |
-| <a name="input_engine_version"></a> [engine\_version](#input\_engine\_version) | Database engine version, depends on engine type | `string` | n/a | yes |
+| <a name="input_engine"></a> [engine](#input\_engine) | Database engine type. Required unless a `snapshot_identifier` or `replicate_source_db` is provided. | `string` | `null` | no |
+| <a name="input_engine_version"></a> [engine\_version](#input\_engine\_version) | Database engine version, depends on engine type. Required unless a `snapshot_identifier` or `replicate_source_db` is provided. | `string` | n/a | yes |
 | <a name="input_environment"></a> [environment](#input\_environment) | ID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT' | `string` | `null` | no |
 | <a name="input_final_snapshot_identifier"></a> [final\_snapshot\_identifier](#input\_final\_snapshot\_identifier) | Final snapshot identifier e.g.: some-db-final-snapshot-2019-06-26-06-05 | `string` | `""` | no |
 | <a name="input_host_name"></a> [host\_name](#input\_host\_name) | The DB host name created in Route53 | `string` | `"db"` | no |

docs/terraform.md

@@ -38,7 +38,7 @@
 | Name | Description | Type | Default | Required |
 |------|-------------|------|---------|:--------:|
 | <a name="input_additional_tag_map"></a> [additional\_tag\_map](#input\_additional\_tag\_map) | Additional key-value pairs to add to each map in `tags_as_list_of_maps`. Not added to `tags` or `id`.<br>This is for some rare cases where resources want additional configuration of tags<br>and therefore take a list of maps with tag key, value, and additional configuration. | `map(string)` | `{}` | no |
-| <a name="input_allocated_storage"></a> [allocated\_storage](#input\_allocated\_storage) | The allocated storage in GBs | `number` | `null` | no |
+| <a name="input_allocated_storage"></a> [allocated\_storage](#input\_allocated\_storage) | The allocated storage in GBs. Required unless a `snapshot_identifier` or `replicate_source_db` is provided. | `number` | `null` | no |
 | <a name="input_allow_major_version_upgrade"></a> [allow\_major\_version\_upgrade](#input\_allow\_major\_version\_upgrade) | Allow major version upgrade | `bool` | `false` | no |
 | <a name="input_allowed_cidr_blocks"></a> [allowed\_cidr\_blocks](#input\_allowed\_cidr\_blocks) | The whitelisted CIDRs which to allow `ingress` traffic to the DB instance | `list(string)` | `[]` | 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 |
@@ -52,10 +52,10 @@
 | <a name="input_charset_name"></a> [charset\_name](#input\_charset\_name) | The character set name to use for DB encoding. [Oracle & Microsoft SQL only](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/db_instance#character_set_name). For other engines use `db_parameter` | `string` | `null` | no |
 | <a name="input_context"></a> [context](#input\_context) | Single object for setting entire context at once.<br>See description of individual variables for details.<br>Leave string and numeric variables as `null` to use default value.<br>Individual variable settings (non-null) override settings in context object,<br>except for attributes, tags, and additional\_tag\_map, which are merged. | `any` | <pre>{<br>  "additional_tag_map": {},<br>  "attributes": [],<br>  "delimiter": null,<br>  "descriptor_formats": {},<br>  "enabled": true,<br>  "environment": null,<br>  "id_length_limit": null,<br>  "label_key_case": null,<br>  "label_order": [],<br>  "label_value_case": null,<br>  "labels_as_tags": [<br>    "unset"<br>  ],<br>  "name": null,<br>  "namespace": null,<br>  "regex_replace_chars": null,<br>  "stage": null,<br>  "tags": {},<br>  "tenant": null<br>}</pre> | no |
 | <a name="input_copy_tags_to_snapshot"></a> [copy\_tags\_to\_snapshot](#input\_copy\_tags\_to\_snapshot) | Copy tags from DB to a snapshot | `bool` | `true` | no |
-| <a name="input_database_name"></a> [database\_name](#input\_database\_name) | The name of the database to create when the DB instance is created | `string` | n/a | yes |
-| <a name="input_database_password"></a> [database\_password](#input\_database\_password) | (Required unless a snapshot\_identifier or replicate\_source\_db is provided) Password for the master DB user | `string` | `""` | no |
+| <a name="input_database_name"></a> [database\_name](#input\_database\_name) | The name of the database to create when the DB instance is created | `string` | `null` | no |
+| <a name="input_database_password"></a> [database\_password](#input\_database\_password) | Password for the primary DB user. Required unless a `snapshot_identifier` or `replicate_source_db` is provided. | `string` | `null` | no |
 | <a name="input_database_port"></a> [database\_port](#input\_database\_port) | Database port (\_e.g.\_ `3306` for `MySQL`). Used in the DB Security Group to allow access to the DB instance from the provided `security_group_ids` | `number` | n/a | yes |
-| <a name="input_database_user"></a> [database\_user](#input\_database\_user) | (Required unless a `snapshot_identifier` or `replicate_source_db` is provided) Username for the master DB user | `string` | `""` | no |
+| <a name="input_database_user"></a> [database\_user](#input\_database\_user) | Username for the primary DB user. Required unless a `snapshot_identifier` or `replicate_source_db` is provided. | `string` | `null` | no |
 | <a name="input_db_options"></a> [db\_options](#input\_db\_options) | A list of DB options to apply with an option group. Depends on DB engine | <pre>list(object({<br>    db_security_group_memberships  = list(string)<br>    option_name                    = string<br>    port                           = number<br>    version                        = string<br>    vpc_security_group_memberships = list(string)<br><br>    option_settings = list(object({<br>      name  = string<br>      value = string<br>    }))<br>  }))</pre> | `[]` | no |
 | <a name="input_db_parameter"></a> [db\_parameter](#input\_db\_parameter) | A list of DB parameters to apply. Note that parameters may differ from a DB family to another | <pre>list(object({<br>    apply_method = string<br>    name         = string<br>    value        = string<br>  }))</pre> | `[]` | no |
 | <a name="input_db_parameter_group"></a> [db\_parameter\_group](#input\_db\_parameter\_group) | The DB parameter group family name. The value depends on DB engine used. See [DBParameterGroupFamily](https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBParameterGroup.html#API_CreateDBParameterGroup_RequestParameters) for instructions on how to retrieve applicable value. | `string` | n/a | yes |
@@ -66,8 +66,8 @@
 | <a name="input_dns_zone_id"></a> [dns\_zone\_id](#input\_dns\_zone\_id) | The ID of the DNS Zone in Route53 where a new DNS record will be created for the DB host name | `string` | `""` | no |
 | <a name="input_enabled"></a> [enabled](#input\_enabled) | Set to false to prevent the module from creating any resources | `bool` | `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) | Database engine type | `string` | `null` | no |
-| <a name="input_engine_version"></a> [engine\_version](#input\_engine\_version) | Database engine version, depends on engine type | `string` | n/a | yes |
+| <a name="input_engine"></a> [engine](#input\_engine) | Database engine type. Required unless a `snapshot_identifier` or `replicate_source_db` is provided. | `string` | `null` | no |
+| <a name="input_engine_version"></a> [engine\_version](#input\_engine\_version) | Database engine version, depends on engine type. Required unless a `snapshot_identifier` or `replicate_source_db` is provided. | `string` | n/a | yes |
 | <a name="input_environment"></a> [environment](#input\_environment) | ID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT' | `string` | `null` | no |
 | <a name="input_final_snapshot_identifier"></a> [final\_snapshot\_identifier](#input\_final\_snapshot\_identifier) | Final snapshot identifier e.g.: some-db-final-snapshot-2019-06-26-06-05 | `string` | `""` | no |
 | <a name="input_host_name"></a> [host\_name](#input\_host\_name) | The DB host name created in Route53 | `string` | `"db"` | no |

examples/complete/variables.tf

@@ -14,12 +14,12 @@ variable "database_name" {
 
 variable "database_user" {
   type        = string
-  description = "Username for the master DB user"
+  description = "Username for the primary DB user"
 }
 
 variable "database_password" {
   type        = string
-  description = "Password for the master DB user"
+  description = "Password for the primary DB user"
 }
 
 variable "database_port" {

examples/mssql/variables.tf

@@ -29,12 +29,12 @@ variable "database_name" {
 
 variable "database_user" {
   type        = string
-  description = "Username for the master DB user"
+  description = "Username for the primary DB user"
 }
 
 variable "database_password" {
   type        = string
-  description = "Password for the master DB user"
+  description = "Password for the primary DB user"
 }
 
 variable "database_port" {

main.tf

@@ -24,14 +24,14 @@ resource "aws_db_instance" "default" {
 
   identifier            = module.this.id
   name                  = var.database_name
-  username              = var.database_user
-  password              = var.database_password
+  username              = try(length(var.replicate_source_db), 0) == 0 ? var.database_user : null
+  password              = try(length(var.replicate_source_db), 0) == 0 ? var.database_password : null
   port                  = var.database_port
-  engine                = var.engine
-  engine_version        = var.engine_version
+  engine                = try(length(var.replicate_source_db), 0) == 0 ? var.engine : null
+  engine_version        = try(length(var.replicate_source_db), 0) == 0 ? var.engine_version : null
   character_set_name    = var.charset_name
   instance_class        = var.instance_class
-  allocated_storage     = var.allocated_storage
+  allocated_storage     = try(length(var.replicate_source_db), 0) == 0 ? var.allocated_storage : null
   max_allocated_storage = var.max_allocated_storage
   storage_encrypted     = var.storage_encrypted
   kms_key_id            = var.kms_key_arn

variables.tf

@@ -30,19 +30,20 @@ variable "associate_security_group_ids" {
 
 variable "database_name" {
   type        = string
+  default     = null
   description = "The name of the database to create when the DB instance is created"
 }
 
 variable "database_user" {
   type        = string
-  default     = ""
-  description = "(Required unless a `snapshot_identifier` or `replicate_source_db` is provided) Username for the master DB user"
+  default     = null
+  description = "Username for the primary DB user. Required unless a `snapshot_identifier` or `replicate_source_db` is provided."
 }
 
 variable "database_password" {
   type        = string
-  default     = ""
-  description = "(Required unless a snapshot_identifier or replicate_source_db is provided) Password for the master DB user"
+  default     = null
+  description = "Password for the primary DB user. Required unless a `snapshot_identifier` or `replicate_source_db` is provided."
 }
 
 variable "database_port" {
@@ -82,7 +83,7 @@ variable "iops" {
 
 variable "allocated_storage" {
   type        = number
-  description = "The allocated storage in GBs"
+  description = "The allocated storage in GBs. Required unless a `snapshot_identifier` or `replicate_source_db` is provided."
   default     = null
 }
 
@@ -94,7 +95,7 @@ variable "max_allocated_storage" {
 
 variable "engine" {
   type        = string
-  description = "Database engine type"
+  description = "Database engine type. Required unless a `snapshot_identifier` or `replicate_source_db` is provided."
   default     = null
   # http://docs.aws.amazon.com/cli/latest/reference/rds/create-db-instance.html
   # - mysql
@@ -105,7 +106,7 @@ variable "engine" {
 
 variable "engine_version" {
   type        = string
-  description = "Database engine version, depends on engine type"
+  description = "Database engine version, depends on engine type. Required unless a `snapshot_identifier` or `replicate_source_db` is provided."
   # http://docs.aws.amazon.com/cli/latest/reference/rds/create-db-instance.html
 }