Support multiple route tables for a single tgw #139
Description
Is your request related to a new offering from AWS?
Is this functionality available in the AWS provider for Terraform?
- Yes ✅: 0.0.0?
I assume we've always been able to associate more than one tgw route table with a tgw?
Is your request related to a problem? Please describe.
We want to associate multiple tgw route tables to a single tgw. We also want to manage routes for each of the tgw route tables.
Within our network account we want to create a tgw per region. Within the region we will create "environment" VPCs, eg prod, nonprod, uat. Each VPC will attach to the tgw but each environment will be routed using a table dedicated to the environment. Thus each tgw will have four route tables, the default, prod, nonprod, and uat.
Describe the solution you'd like.
It would be great if we could create n tgw route tables for a tgw and associate attachments with one of the tgw route tables.
Describe alternatives you've considered.
A main module and then one module instance per "environment".
This is unworkable, because tgw route tables are only managed when create_tgw and create_tgw_routes are both true.
module "transit_gateway" {
source = "terraform-aws-modules/transit-gateway/aws"
version = "2.13.0"
name = var.tgw_name
vpc_attachments = var.tgw_vpc_attachments
transit_gateway_cidr_blocks = var.tgw_cidr_blocks
amazon_side_asn = "64535"
create_tgw = true
tgw_default_route_table_tags = data.aws_default_tags.aws.tags
tgw_route_table_tags = data.aws_default_tags.aws.tags
tgw_vpc_attachment_tags = data.aws_default_tags.aws.tags
tgw_tags = data.aws_default_tags.aws.tags
enable_auto_accept_shared_attachments = var.tgw_enable_auto_accept_shared_attachments
}
module "nonprod" {
source = "terraform-aws-modules/transit-gateway/aws"
version = "2.13.0"
# 💥 this configuration would not lead to tgw route table creation 😢 💥
# https://github.com/terraform-aws-modules/terraform-aws-transit-gateway/blob/master/main.tf#L94
create_tgw = false
create_tgw_routes = true
vpc_attachments = {
"nonprod" = {
name = "some-non-prod-thing"
tgw_id = module.transit_gateway.ec2_transit_gateway_id
description = "some-non-prod-thing attachment to network"
vpc_id = module.vpc.vpc_id
subnet_ids = module.vpc.private_subnets
vpc_route_table_ids = module.vpc.private_route_table_ids
tgw_destination_cidr = "10.0.0.0/8"
security_group_referencing_support = false
dns_support = true
ipv6_support = false
transit_gateway_default_route_table_association = false
transit_gateway_default_route_table_propagation = false
}
}
}