feat: Optionally update VPC Route Tables for attached VPCs (#35)

Author: jmcorallo

README.md

@@ -96,6 +96,7 @@ No modules.
 | [aws_ram_resource_association.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/ram_resource_association) | resource |
 | [aws_ram_resource_share.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/ram_resource_share) | resource |
 | [aws_ram_resource_share_accepter.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/ram_resource_share_accepter) | resource |
+| [aws_route.this](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/route) | resource |
 
 ## Inputs
 

main.tf

@@ -19,6 +19,15 @@ locals {
     var.tags,
     var.tgw_default_route_table_tags,
   )
+
+  vpc_route_table_destination_cidr = flatten([
+    for k, v in var.vpc_attachments : [
+      for rtb_id in lookup(v, "vpc_route_table_ids", []) : {
+        rtb_id = rtb_id
+        cidr   = v["tgw_destination_cidr"]
+      }
+    ]
+  ])
 }
 
 resource "aws_ec2_transit_gateway" "this" {
@@ -76,6 +85,14 @@ resource "aws_ec2_transit_gateway_route" "this" {
   transit_gateway_attachment_id  = tobool(lookup(local.vpc_attachments_with_routes[count.index][1], "blackhole", false)) == false ? aws_ec2_transit_gateway_vpc_attachment.this[local.vpc_attachments_with_routes[count.index][0]["key"]].id : null
 }
 
+resource "aws_route" "this" {
+  for_each = { for x in local.vpc_route_table_destination_cidr : x.rtb_id => x.cidr }
+
+  route_table_id         = each.key
+  destination_cidr_block = each.value
+  transit_gateway_id     = aws_ec2_transit_gateway.this[0].id
+}
+
 ###########################################################
 # VPC Attachments, route table association and propagation
 ###########################################################