fix: Output list of external_nat_ips when using external eips (#432)

Author: DrFaust92

README.md

@@ -453,6 +453,7 @@ It is possible to integrate this VPC module with [terraform-aws-transit-gateway
 | events\_endpoint\_security\_group\_ids | The ID of one or more security groups to associate with the network interface for CloudWatch Events endpoint | `list(string)` | `[]` | no |
 | events\_endpoint\_subnet\_ids | The ID of one or more subnets in which to create a network interface for CloudWatch Events endpoint. Only a single subnet within an AZ is supported. If omitted, private subnets will be used. | `list(string)` | `[]` | no |
 | external\_nat\_ip\_ids | List of EIP IDs to be assigned to the NAT Gateways (used in combination with reuse\_nat\_ips) | `list(string)` | `[]` | no |
+| external\_nat\_ips | List of EIPs to be used for `nay_public_ips` output (used in combination with reuse\_nat\_ips and external\_nat\_ip\_ids) | `list(string)` | `[]` | no |
 | flow\_log\_cloudwatch\_iam\_role\_arn | The ARN for the IAM role that's used to post flow logs to a CloudWatch Logs log group. When flow\_log\_destination\_arn is set to ARN of Cloudwatch Logs, this argument needs to be provided. | `string` | `""` | no |
 | flow\_log\_cloudwatch\_log\_group\_kms\_key\_id | The ARN of the KMS Key to use when encrypting log data for VPC flow logs. | `string` | `null` | no |
 | flow\_log\_cloudwatch\_log\_group\_name\_prefix | Specifies the name prefix of CloudWatch Log Group for VPC flow logs. | `string` | `"/aws/vpc-flow-log/"` | no |

outputs.tf

@@ -320,7 +320,7 @@ output "nat_ids" {
 
 output "nat_public_ips" {
   description = "List of public Elastic IPs created for AWS NAT Gateway"
-  value       = aws_eip.nat.*.public_ip
+  value       = var.reuse_nat_ips ? var.external_nat_ips : aws_eip.nat.*.public_ip
 }
 
 output "natgw_ids" {

variables.tf

@@ -298,6 +298,12 @@ variable "external_nat_ip_ids" {
   default     = []
 }
 
+variable "external_nat_ips" {
+  description = "List of EIPs to be used for `nay_public_ips` output (used in combination with reuse_nat_ips and external_nat_ip_ids)"
+  type        = list(string)
+  default     = []
+}
+
 variable "enable_dynamodb_endpoint" {
   description = "Should be true if you want to provision a DynamoDB endpoint to the VPC"
   type        = bool