fix: allow IPv6 IPAM pool without requiring IPv4 IPAM

Author: owen-method

main.tf

@@ -30,11 +30,11 @@ resource "aws_vpc" "this" {
 
   region = var.region
 
-  cidr_block          = var.use_ipam_pool ? null : var.cidr
+  cidr_block          = var.use_ipam_pool && var.ipv4_ipam_pool_id != null ? null : var.cidr
   ipv4_ipam_pool_id   = var.ipv4_ipam_pool_id
   ipv4_netmask_length = var.ipv4_netmask_length
 
-  assign_generated_ipv6_cidr_block     = var.enable_ipv6 && !var.use_ipam_pool ? true : null
+  assign_generated_ipv6_cidr_block     = var.enable_ipv6 && !var.use_ipam_pool && var.ipv6_ipam_pool_id == null ? true : null
   ipv6_cidr_block                      = var.ipv6_cidr
   ipv6_ipam_pool_id                    = var.ipv6_ipam_pool_id
   ipv6_netmask_length                  = var.ipv6_netmask_length