feat(vpc): add named subnets (#1032)

Signed-off-by: nitrocode <7775707+nitrocode@users.noreply.github.com>
Co-authored-by: Dan Miller <daniel@cloudposse.com>

modules/vpc/README.md

@@ -131,6 +131,8 @@ components:
 | <a name="input_region"></a> [region](#input\_region) | AWS Region | `string` | n/a | yes |
 | <a name="input_stage"></a> [stage](#input\_stage) | ID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release' | `string` | `null` | no |
 | <a name="input_subnet_type_tag_key"></a> [subnet\_type\_tag\_key](#input\_subnet\_type\_tag\_key) | Key for subnet type tag to provide information about the type of subnets, e.g. `cpco/subnet/type=private` or `cpcp/subnet/type=public` | `string` | n/a | yes |
+| <a name="input_subnets_per_az_count"></a> [subnets\_per\_az\_count](#input\_subnets\_per\_az\_count) | The number of subnet of each type (public or private) to provision per Availability Zone. | `number` | `1` | no |
+| <a name="input_subnets_per_az_names"></a> [subnets\_per\_az\_names](#input\_subnets\_per\_az\_names) | The subnet names of each type (public or private) to provision per Availability Zone.<br>This variable is optional.<br>If a list of names is provided, the list items will be used as keys in the outputs `named_private_subnets_map`, `named_public_subnets_map`,<br>`named_private_route_table_ids_map` and `named_public_route_table_ids_map` | `list(string)` | <pre>[<br>  "common"<br>]</pre> | no |
 | <a name="input_tags"></a> [tags](#input\_tags) | Additional tags (e.g. `{'BusinessUnit': 'XYZ'}`).<br>Neither the tag keys nor the tag values will be modified by this module. | `map(string)` | `{}` | no |
 | <a name="input_tenant"></a> [tenant](#input\_tenant) | ID element \_(Rarely used, not included by default)\_. A customer identifier, indicating who this instance of a resource is for | `string` | `null` | no |
 | <a name="input_vpc_flow_logs_bucket_environment_name"></a> [vpc\_flow\_logs\_bucket\_environment\_name](#input\_vpc\_flow\_logs\_bucket\_environment\_name) | The name of the environment where the VPC Flow Logs bucket is provisioned | `string` | `""` | no |

modules/vpc/main.tf

@@ -157,6 +157,8 @@ module "subnets" {
   public_subnets_additional_tags  = local.public_subnets_additional_tags
   private_subnets_additional_tags = local.private_subnets_additional_tags
   vpc_id                          = module.vpc.vpc_id
+  subnets_per_az_count            = var.subnets_per_az_count
+  subnets_per_az_names            = var.subnets_per_az_names
 
   context = module.this.context
 }

modules/vpc/variables.tf

@@ -207,3 +207,30 @@ variable "interface_vpc_endpoints" {
   description = "A list of Interface VPC Endpoints to provision into the VPC."
   default     = []
 }
+
+variable "subnets_per_az_count" {
+  type        = number
+  description = <<-EOT
+    The number of subnet of each type (public or private) to provision per Availability Zone.
+  EOT
+  default     = 1
+  nullable    = false
+  validation {
+    condition = var.subnets_per_az_count > 0
+    # Validation error messages must be on a single line, among other restrictions.
+    # See https://github.com/hashicorp/terraform/issues/24123
+    error_message = "The `subnets_per_az` value must be greater than 0."
+  }
+}
+
+variable "subnets_per_az_names" {
+  type        = list(string)
+  description = <<-EOT
+    The subnet names of each type (public or private) to provision per Availability Zone.
+    This variable is optional.
+    If a list of names is provided, the list items will be used as keys in the outputs `named_private_subnets_map`, `named_public_subnets_map`,
+    `named_private_route_table_ids_map` and `named_public_route_table_ids_map`
+  EOT
+  default     = ["common"]
+  nullable    = false
+}