Add spare subnets module

Author: hazim1093

modules/network.tf

@@ -26,6 +26,11 @@ variable "private_persistence_subnets" {
   default     = []
 }
 
+variable "spare_subnets" {
+  description = "A list of CIDR blocks for spare subnets inside the VPC."
+  default     = []
+}
+
 ## VPC-Peering variables
 # Default values assigned inorder to mark them optional
 variable "peer_vpc_id" {
@@ -112,6 +117,15 @@ module "private_persistence_subnet" {
   azs                         = "${var.azs}"
 }
 
+module "spare_subnet" {
+  source = "./spare-subnet"
+
+  name          = "${var.name}-spare"
+  vpc_id        = "${module.vpc.vpc_id}"
+  spare_subnets = "${var.spare_subnets}"
+  azs           = "${var.azs}"
+}
+
 module "network_acl" {
   source = "./network-acl"
 

modules/spare-subnet/main.tf

@@ -0,0 +1,10 @@
+resource "aws_subnet" "spare" {
+  vpc_id            = "${var.vpc_id}"
+  cidr_block        = "${var.spare_subnets[count.index]}"
+  availability_zone = "${var.azs[count.index]}"
+  count             = "${length(var.azs)}"
+
+  tags {
+    Name = "${var.name}-${var.azs[count.index]}"
+  }
+}

modules/spare-subnet/output.tf

@@ -0,0 +1,3 @@
+output "subnet_ids" {
+  value = "${join(",", aws_subnet.spare.*.id)}"
+}

modules/spare-subnet/variables.tf

@@ -0,0 +1,15 @@
+variable "name" {
+  default = "spare"
+}
+
+variable "vpc_id" {}
+
+variable "spare_subnets" {
+  description = "A list of CIDR blocks for spare subnets inside the VPC."
+  type        = "list"
+}
+
+variable "azs" {
+  description = "A list of Availability zones in the region"
+  type        = "list"
+}