update

vpc-transit-gateway-association/routing.tf

@@ -1,5 +1,6 @@
 module "routing_attachment_ipv4" {
   source = "git@github.e.it.census.gov:terraform-modules/aws-vpc-setup.git//routing?ref=tf-upgrade"
+  count  = var.transit_gateway_routing_type == "self" ? 1 : 0
   vpc_id = var.vpc_id
 
   vpc_full_name      = var.vpc_full_name
@@ -38,12 +39,13 @@ data "aws_ec2_managed_prefix_list" "tgw_ipv4" {
 
 # pick the first prefix list found, either NAME or NAME.ipv4
 resource "aws_route" "gateway_ipv4" {
-  for_each = module.routing_ipv4.private_route_table_ids
+  count    = var.transit_gateway_routing_type == "self" ? 1 : 0
+  for_each = var.transit_gateway_routing_type == "self" ? module.routing_attachment_ipv4[0].private_route_table_ids : {}
 
   route_table_id = each.value
   #  destination_cidr_block = "10.128.0.0/16"
   destination_prefix_list_id = one([for k, v in data.aws_ec2_managed_prefix_list.tgw_ipv4 : k if v.address_family == "IPv4"])
-  transit_gateway_id         = data.aws_ec2_transit_gateway.gateway_east.id
+  transit_gateway_id         = data.aws_ec2_transit_gateway.gateway_self.id
 
-  depends_on = [aws_ec2_transit_gateway_vpc_attachment.vpc_attachment]
+  depends_on = var.transit_gateway_routing_type == "self" ? [aws_ec2_transit_gateway_vpc_attachment.vpc_attachment] : []
 }