added outpost subnet support and example

Author: brylex418

examples/outpost-subnets/main.tf

@@ -0,0 +1,36 @@
+provider "aws" {
+  region = "us-west-2"
+}
+
+module "vpc" {
+  source = "../terraform-aws-vpc"
+
+  name = "outpost-example"
+
+  cidr = "10.0.0.0/16"
+
+  azs                   = ["us-west-2a", "us-west-2b", "us-west-2c"]
+  private_subnets       = ["10.0.1.0/24", "10.0.2.0/24", "10.0.3.0/24"]
+  public_subnets        = ["10.0.101.0/24", "10.0.102.0/24", "10.0.103.0/24"]
+  outpost_subnets       = ["10.0.50.0/24"]
+  create_outpost_subnet = true
+  outpost_arn = "arn:aws:outposts:us-west-2:116668991109:outpost/op-0a8c1ab53b023a5a4"
+
+  enable_ipv6 = true
+
+  enable_nat_gateway = true
+  single_nat_gateway = true
+
+  public_subnet_tags = {
+    Name = "overridden-name-public"
+  }
+
+  tags = {
+    Owner       = "user"
+    Environment = "dev"
+  }
+
+  vpc_tags = {
+    Name = "vpc-name"
+  }
+}

main.tf

@@ -419,6 +419,30 @@ resource "aws_subnet" "private" {
   )
 }
 
+#################
+# Outpost subnet
+#################
+resource "aws_subnet" "outpost" {
+  count = var.create_vpc && var.create_outpost_subnet == true ? length(var.outpost_subnets) : 0
+
+  vpc_id     = local.vpc_id
+  cidr_block = var.outpost_subnets[count.index]
+  availability_zone    = var.outpost_az
+  outpost_arn = var.outpost_arn
+
+  tags = merge(
+    {
+      "Name" = format(
+        "%s-${var.outpost_subnet_suffix}-%s",
+        var.name,
+        element(var.azs, count.index),
+      )
+    },
+    var.tags,
+    var.outpost_subnet_tags,
+  )
+}
+
 ##################
 # Database subnet
 ##################
@@ -1042,6 +1066,16 @@ resource "aws_route_table_association" "private" {
   )
 }
 
+resource "aws_route_table_association" "outpost" {
+  count = var.create_vpc && var.create_outpost_subnet == true ? length(var.outpost_subnets) : 0
+
+  subnet_id = element(aws_subnet.outpost.*.id, count.index)
+  route_table_id = element(
+  aws_route_table.private.*.id,
+  var.single_nat_gateway ? 0 : count.index,
+  )
+}
+
 resource "aws_route_table_association" "database" {
   count = var.create_vpc && length(var.database_subnets) > 0 ? length(var.database_subnets) : 0
 
@@ -1201,3 +1235,4 @@ resource "aws_default_vpc" "this" {
     var.default_vpc_tags,
   )
 }
+

variables.tf

@@ -124,6 +124,12 @@ variable "private_subnet_suffix" {
   default     = "private"
 }
 
+variable "outpost_subnet_suffix" {
+  description = "Suffix to append to outpost subnets name"
+  type        = string
+  default     = "outpost"
+}
+
 variable "intra_subnet_suffix" {
   description = "Suffix to append to intra subnets name"
   type        = string
@@ -160,6 +166,12 @@ variable "private_subnets" {
   default     = []
 }
 
+variable "outpost_subnets" {
+  description = "A list of outpost subnets inside the VPC"
+  type        = list(string)
+  default     = []
+}
+
 variable "database_subnets" {
   description = "A list of database subnets"
   type        = list(string)
@@ -2267,6 +2279,12 @@ variable "private_subnet_tags" {
   default     = {}
 }
 
+variable "outpost_subnet_tags" {
+  description = "Additional tags for the outpost subnets"
+  type        = map(string)
+  default     = {}
+}
+
 variable "public_route_table_tags" {
   description = "Additional tags for the public route tables"
   type        = map(string)
@@ -2902,3 +2920,21 @@ variable "create_egress_only_igw" {
   type        = bool
   default     = true
 }
+
+variable "create_outpost_subnet" {
+  description = "Controls if an outpost subnet is deployed"
+  type        = bool
+  default     = false
+}
+
+variable "outpost_arn" {
+  description = "ARN of outpost you want to create a subnet in"
+  type = string
+  default = ""
+}
+
+variable "outpost_az" {
+  description = "AZ where outpost is anchored"
+  type = string
+  default = ""
+}