Adds option to route the entire VPC through the TGW

README.md

@@ -61,6 +61,7 @@ Check the `subnet_name_keyword_selector` variable if you want to change this.
 | hub\_destination\_cidr\_blocks | List of CIDRs to be routed for the hub | `list` | `[]` | no |
 | ram\_resource\_association\_id | Identifier of the Resource Access Manager Resource Association | `string` | `""` | no |
 | role\_to\_assume\_satellite | IAM role name to assume in the AWS account containing the TGW satellite (eg. ASSUME-ROLE-SATELLITE) | `string` | `""` | no |
+| route\_entire\_satellite\_vpc | Boolean flag for toggling the creation of network routes for all the subnets of the satellite VPC | `bool` | `false` | no |
 | satellite\_create | Boolean flag for toggling the handling of satellite resources | `bool` | `false` | no |
 | satellite\_destination\_cidr\_blocks | List of CIDRs to be routed for the satellite | `list` | `[]` | no |
 | subnet\_filters | List of maps selecting the subnet(s) for which the routing will be added | <pre>list(object({<br>    name   = string<br>    values = list(string)<br>  }))<br></pre> | <pre>[<br>  {<br>    "name": "tag:Name",<br>    "values": [<br>      "private"<br>    ]<br>  }<br>]<br></pre> | no |
@@ -82,7 +83,6 @@ Check the `subnet_name_keyword_selector` variable if you want to change this.
 - Collect TGW ID directly rather than using a RAM data source
   ([currently not supported][7])
 - Add support for VPN attachments
-- Add support for passing IDs of subnets while fetching routing table IDs
 
 [1]: https://en.wikipedia.org/wiki/Star_network
 [2]: https://github.com/Flaconi/terraform-aws-transit-gateway-hub

data.tf

@@ -28,6 +28,12 @@ data "aws_route_table" "this" {
   subnet_id = sort(data.aws_subnet_ids.this[0].ids)[count.index]
 }
 
+data "aws_route_tables" "all" {
+  provider = aws.satellite
+  count    = local.create && var.route_entire_satellite_vpc ? 1 : 0
+  vpc_id   = data.aws_vpc.this[0].id
+}
+
 data "aws_ec2_transit_gateway" "this" {
   provider = aws.hub
   count    = local.create && var.transit_gateway_hub_name != "" ? 1 : 0

examples/satellite/README.md

@@ -15,6 +15,7 @@ No provider.
 | role\_to\_assume\_hub | IAM role name to assume in the AWS account containing the TGW hub (eg. ASSUME-ROLE-HUB) | `string` | n/a | yes |
 | role\_to\_assume\_satellite | IAM role name to assume in the AWS account containing the TGW satellite (eg. ASSUME-ROLE-SATELLITE) | `string` | n/a | yes |
 | hub\_destination\_cidr\_blocks | List of CIDRs to be routed for the hub | `list` | `[]` | no |
+| route\_entire\_satellite\_vpc | Boolean flag for toggling the creation of network routes for all the subnets of the satellite VPC | `bool` | `false` | no |
 | satellite\_create | Boolean flag for toggling the handling of satellite resources | `bool` | `false` | no |
 | satellite\_destination\_cidr\_blocks | List of CIDRs to be routed for the satellite | `list` | `[]` | no |
 | subnet\_filters | List of maps selecting the subnet(s) for which the routing will be added | <pre>list(object({<br>    name   = string<br>    values = list(string)<br>  }))<br></pre> | <pre>[<br>  {<br>    "name": "tag:Name",<br>    "values": [<br>      "private"<br>    ]<br>  }<br>]<br></pre> | no |

examples/satellite/main.tf

@@ -25,4 +25,6 @@ module "tgw-satellite" {
   subnet_filters = var.subnet_filters
 
   transit_gateway_hub_name = var.transit_gateway_hub_name
+
+  route_entire_satellite_vpc = var.route_entire_satellite_vpc
 }

examples/satellite/variables.auto.tfvars

@@ -22,3 +22,5 @@ subnet_filters = [
 ]
 
 transit_gateway_hub_name = "test-tgw-fixture"
+
+route_entire_satellite_vpc = true

examples/satellite/variables.tf

@@ -71,3 +71,9 @@ variable "transit_gateway_id" {
   type        = string
   default     = ""
 }
+
+variable "route_entire_satellite_vpc" {
+  description = "Boolean flag for toggling the creation of network routes for all the subnets of the satellite VPC"
+  type        = bool
+  default     = false
+}

locals.tf

@@ -6,7 +6,7 @@ locals {
   transit_gateway_route_table_id = var.transit_gateway_route_table_id == "" ? data.aws_ec2_transit_gateway_route_table.this[0].id : var.transit_gateway_route_table_id
 
   routes_in_tables = [
-    for pair in setproduct(data.aws_route_table.this[*].route_table_id, var.satellite_destination_cidr_blocks) : {
+    for pair in setproduct(var.route_entire_satellite_vpc ? data.aws_route_tables.all[0].ids : data.aws_route_table.this[*].route_table_id, var.satellite_destination_cidr_blocks) : {
       table_id        = pair[0]
       dest_cidr_block = pair[1]
     }

variables.tf

@@ -85,3 +85,9 @@ variable "transit_gateway_hub_name" {
   type        = string
   default     = ""
 }
+
+variable "route_entire_satellite_vpc" {
+  description = "Boolean flag for toggling the creation of network routes for all the subnets of the satellite VPC"
+  type        = bool
+  default     = false
+}