Core 2711

main.tf

@@ -12,10 +12,14 @@ locals {
 
   vpc_route_table_destination_cidr = flatten([
     for k, v in var.vpc_attachments : [
-      for rtb_id in try(v.vpc_route_table_ids, []) : {
-        rtb_id = rtb_id
-        cidr   = v.tgw_destination_cidr
-      }
+      for rtb_id in try(v.vpc_route_table_ids, []) : [
+        for tgw_route in try(v.tgw_routes, []) : {
+          vpc_attachment_id = k
+          rtb_id            = rtb_id
+          cidr              = tgw_route.destination_cidr_block
+          tgw_id            = v.tgw_id
+        }
+      ]
     ]
   ])
 }
@@ -110,11 +114,11 @@ resource "aws_ec2_transit_gateway_route" "this" {
 }
 
 resource "aws_route" "this" {
-  for_each = { for x in local.vpc_route_table_destination_cidr : x.rtb_id => x.cidr }
+  for_each = { for index, x in local.vpc_route_table_destination_cidr : "${x.tgw_id}-${x.rtb_id}-${x.cidr}" => { "rtb_id" : x.rtb_id, "cidr" : x.cidr, "tgw_id" : x.tgw_id } }
 
-  route_table_id         = each.key
-  destination_cidr_block = each.value
-  transit_gateway_id     = aws_ec2_transit_gateway.this[0].id
+  route_table_id         = each.value.rtb_id
+  destination_cidr_block = each.value.cidr
+  transit_gateway_id     = var.create_tgw ? aws_ec2_transit_gateway.this[0].id : each.value.tgw_id
 }
 
 resource "aws_ec2_transit_gateway_route_table_association" "this" {
@@ -173,3 +177,55 @@ resource "aws_ram_resource_share_accepter" "this" {
 
   share_arn = var.ram_resource_share_arn
 }
+
+# Transit Gateway Peering Attachment
+resource "aws_ec2_transit_gateway_peering_attachment" "this" {
+  for_each = var.tgw_peering_attachments
+
+  transit_gateway_id         = aws_ec2_transit_gateway.this[0].id
+  peer_transit_gateway_id    = each.value.peer_transit_gateway_id
+  peer_region                = each.value.peer_region
+  peer_account_id            = each.value.peer_account_id
+
+  tags = merge(
+    var.tags,
+    { Name = "${var.name}-peering-${each.key}" }
+  )
+
+  lifecycle {
+    create_before_destroy = true
+  }
+}
+
+# Accepting Peering Attachment
+resource "aws_ec2_transit_gateway_peering_attachment_accepter" "this" {
+  count = length([for k, v in var.tgw_peering_attachments : v if v.request_accepter])
+
+  transit_gateway_attachment_id = tolist([for attachment in aws_ec2_transit_gateway_peering_attachment.this : attachment.id])[count.index]
+
+  tags = merge(
+    var.tags,
+    { Name = "${var.name}-peering-accepter-${count.index}" }
+  )
+}
+
+# Transit Gateway Peering Route Table
+resource "aws_ec2_transit_gateway_route_table" "peering" {
+  count = length(var.tgw_peering_attachments) > 0 ? 1 : 0
+
+  transit_gateway_id = aws_ec2_transit_gateway.this[0].id
+
+  tags = merge(
+    var.tags,
+    { Name = "${var.name}-tgw-peering-route-table" }
+  )
+}
+
+# Routes for Peering Attachments
+resource "aws_ec2_transit_gateway_route" "peering" {
+  for_each = { for r in var.tgw_peering_route_table_routes : "${r.peering_attachment_key}-${r.destination_cidr_block}" => r }
+
+  destination_cidr_block         = each.value.destination_cidr_block
+  transit_gateway_route_table_id = aws_ec2_transit_gateway_route_table.peering[0].id
+  transit_gateway_attachment_id  = aws_ec2_transit_gateway_peering_attachment.this[each.value.peering_attachment_key].id
+}

variables.tf

@@ -163,3 +163,27 @@ variable "ram_tags" {
   type        = map(string)
   default     = {}
 }
+
+################################################################################
+# TGW Peering Settings
+################################################################################
+variable "tgw_peering_attachments" {
+  description = "A map of transit gateway peering attachments"
+  type = map(object({
+    peer_transit_gateway_id = string
+    peer_region             = string
+    peer_account_id         = string
+    request_accepter        = bool
+  }))
+  default = {}
+}
+
+variable "tgw_peering_route_table_routes" {
+  description = "A list of routes for the Transit Gateway Peering Route Table"
+  type = list(object({
+    destination_cidr_block = string
+    peering_attachment_key = string
+  }))
+  default = []
+}
+