feat: Add support for multiple VPCs when creating private hosted zones (#27)

examples/complete/main.tf

@@ -22,9 +22,14 @@ module "zones" {
 
     "private-vpc.terraform-aws-modules-example.com" = {
       comment = "private-vpc.terraform-aws-modules-example.com"
-      vpc = {
+      vpc = [
+        {
           vpc_id = module.vpc.vpc_id
-      }
+        },
+        {
+          vpc_id = module.vpc2.vpc_id
+        },
+      ]
       tags = {
         Name = "private-vpc.terraform-aws-modules-example.com"
       }
@@ -141,3 +146,10 @@ module "vpc" {
   name = "my-vpc-for-private-route53-zone"
   cidr = "10.0.0.0/16"
 }
+
+module "vpc2" {
+  source = "terraform-aws-modules/vpc/aws"
+
+  name = "my-second-vpc-for-private-route53-zone"
+  cidr = "10.1.0.0/16"
+}

examples/complete/outputs.tf

+# zones
+output "this_route53_zone_zone_id" {
+  description = "Zone ID of Route53 zone"
+  value       = module.zones.this_route53_zone_zone_id
+}
+
+output "this_route53_zone_name_servers" {
+  description = "Name servers of Route53 zone"
+  value       = module.zones.this_route53_zone_name_servers
+}
+
+output "this_route53_zone_name" {
+  description = "Name of Route53 zone"
+  value       = module.zones.this_route53_zone_name
+}
+
+# records
 output "this_route53_record_name" {
   description = "The name of the record"
   value       = module.records.this_route53_record_name

modules/zones/main.tf

@@ -6,7 +6,7 @@ resource "aws_route53_zone" "this" {
   force_destroy = lookup(each.value, "force_destroy", false)
 
   dynamic "vpc" {
-    for_each = length(keys(lookup(each.value, "vpc", {}))) == 0 ? [] : [lookup(each.value, "vpc", {})]
+    for_each = try(tolist(lookup(each.value, "vpc", [])), [lookup(each.value, "vpc", {})])
 
     content {
       vpc_id     = vpc.value.vpc_id

modules/zones/outputs.tf

@@ -7,3 +7,8 @@ output "this_route53_zone_name_servers" {
   description = "Name servers of Route53 zone"
   value       = { for k, v in aws_route53_zone.this : k => v.name_servers }
 }
+
+output "this_route53_zone_name" {
+  description = "Name of Route53 zone"
+  value       = { for k, v in aws_route53_zone.this : k => v.name }
+}