Add multi tier selection option

Author: opensource4learn

main.tf

@@ -1,4 +1,8 @@
 # AWS VPC
+provider "aws" {
+  region = "ap-south-1"
+}
+
 terraform {
   required_version = ">= 0.12.0"
 }
@@ -33,6 +37,7 @@ module "public_subnet" {
   cluster_prefix          = var.cluster_prefix
   cluster_environment     = var.cluster_environment
   subnet_type             = ["public"]
+  cluster_architecture = var.cluster_architecture
 }
 
 # AWS NAT Gateway Module
@@ -53,12 +58,13 @@ module "private_subnet" {
   cluster_environment = var.cluster_environment
   subnet_bits         = var.subnet_bits
   subnet_type         = ["private", "storage"]
+  cluster_architecture = var.cluster_architecture
 }
 
 # AWS VPC Security Groups Module
 module "security_group" {
-  source              = "./modules/security-groups"
-  vpc_id              = aws_vpc.vpc.id
-  cluster_prefix      = var.cluster_prefix
-  cluster_environment = var.cluster_environment
+  source               = "./modules/security-groups"
+  vpc_id               = aws_vpc.vpc.id
+  cluster_prefix       = var.cluster_prefix
+  cluster_environment  = var.cluster_environment
 }

modules/subnets/main.tf

@@ -5,38 +5,44 @@ data "aws_availability_zones" "available_zones" {}
 module "aws_public_subnet" {
   source              = "./resources"
   create              = contains(var.subnet_type, "public") ? 1 : 0
+  tier                = var.cluster_architecture == "1-tier" ? 1 : 0
   cluster_prefix      = var.cluster_prefix
   cluster_environment = var.cluster_environment
   vpc_id              = var.vpc_id
   cidr                = var.cidr
   subnet_bits         = var.subnet_bits
   subnet_type         = "public"
+  cluster_architecture  = var.cluster_architecture
 }
 
 # AWS Private Subnets
 module "aws_private_subnet" {
   source              = "./resources"
   create              = contains(var.subnet_type, "private") ? 1 : 0
+  tier                = var.cluster_architecture == "2-tier" ? 1 : 0
   cluster_prefix      = var.cluster_prefix
   cluster_environment = var.cluster_environment
   vpc_id              = var.vpc_id
   cidr                = var.cidr
   offset              = length(data.aws_availability_zones.available_zones.names)
   subnet_bits         = var.subnet_bits
   subnet_type         = "private"
+  cluster_architecture  = var.cluster_architecture
 }
 
 # AWS Storage Subnets
 module "aws_storage_subnet" {
   source              = "./resources"
   create              = contains(var.subnet_type, "storage") ? 1 : 0
+  tier                = var.cluster_architecture == "3-tier" ? 1 : 0
   cluster_prefix      = var.cluster_prefix
   cluster_environment = var.cluster_environment
   cidr                = var.cidr
   vpc_id              = var.vpc_id
   offset              = 2 * length(data.aws_availability_zones.available_zones.names)
   subnet_bits         = var.subnet_bits
   subnet_type         = "storage"
+  cluster_architecture  = var.cluster_architecture
 }
 
 # AWS Route Tables - Public Route
@@ -49,7 +55,7 @@ resource "aws_route" "public_route" {
 
 # AWS Route Tables - Private Route
 resource "aws_route" "private_route" {
-  count                  = contains(var.subnet_type, "private") ? length(data.aws_availability_zones.available_zones.names) : 0
+  count                  = var.cluster_architecture == "2-tier" || var.cluster_architecture == "3-tier" && contains(var.subnet_type, "private") ? length(data.aws_availability_zones.available_zones.names) : 0
   route_table_id         = module.aws_private_subnet.route_table_ids[count.index]
   destination_cidr_block = "0.0.0.0/0"
   nat_gateway_id         = var.aws_nat_gateway_id[count.index]

modules/subnets/resources/main.tf

@@ -4,7 +4,7 @@ data "aws_availability_zones" "available_zones" {}
 # AWS Subnets
 resource "aws_subnet" "subnets" {
   vpc_id            = var.vpc_id
-  count             = var.create > 0 ? length(data.aws_availability_zones.available_zones.names) : 0
+  count             = var.create > 0 && var.tier > 0 ? length(data.aws_availability_zones.available_zones.names) : 0
   cidr_block        = cidrsubnet(var.cidr, var.subnet_bits, var.offset + count.index)
   availability_zone = data.aws_availability_zones.available_zones.names[count.index]
 
@@ -18,7 +18,7 @@ resource "aws_subnet" "subnets" {
 # AWS Route Tables
 resource "aws_route_table" "route_table" {
   vpc_id = var.vpc_id
-  count  = var.create > 0 ? length(data.aws_availability_zones.available_zones.names) : 0
+  count  = var.create > 0 && var.tier > 0 ? length(data.aws_availability_zones.available_zones.names) : 0
 
   tags = {
     Name        = "${var.cluster_prefix}-${var.subnet_type}-${count.index + 1}"
@@ -29,7 +29,7 @@ resource "aws_route_table" "route_table" {
 
 # AWS Route Table - Subnet Association 
 resource "aws_route_table_association" "subnet_association" {
-  count          = var.create > 0 ? length(data.aws_availability_zones.available_zones.names) : 0
+  count          = var.create > 0 && var.tier > 0 ? length(data.aws_availability_zones.available_zones.names) : 0
   subnet_id      = element(aws_subnet.subnets.*.id, count.index)
   route_table_id = element(aws_route_table.route_table.*.id, count.index)
 }

modules/subnets/resources/variables.tf

@@ -19,6 +19,11 @@ variable "cluster_environment" {
   type        = string
 }
 
+variable "cluster_architecture" {
+  description = "To apply generic cluster_architecture to AWS VPC Resources"
+  type        = string
+}
+
 variable "cidr" {
   description = "CIDR block value is the size of the VPC"
   type        = string
@@ -29,6 +34,11 @@ variable "create" {
   type        = string
 }
 
+variable "tier" {
+  description = "tier"
+  type        = string
+}
+
 variable "subnet_bits" {
   description = "Subnet bits for cidrsubnet interpolation or Size we need to define for the Subnet (cidr of VPC + Subnet bits)"
   type        = string

modules/subnets/variables.tf

@@ -25,6 +25,11 @@ variable "cluster_environment" {
   type        = string
 }
 
+variable "cluster_architecture" {
+  description = "To apply generic cluster_environment to AWS VPC Resources"
+  type        = string
+}
+
 variable "subnet_bits" {
   description = "Subnet bits for cidrsubnet interpolation or Size we need to define for the Subnet (cidr of VPC + Subnet bits)"
   type        = string

variables.tf

@@ -2,19 +2,29 @@
 variable "cluster_prefix" {
   description = "To apply generic naming to AWS VPC Resources"
   type        = string
+  default     = "copper"
 }
 
 variable "cluster_environment" {
+  description = "To apply generic environment to AWS VPC Resources"
+  type        = string
+  default     = "devops"
+}
+
+variable "cluster_architecture" {
   description = "To apply generic cluster_environment to AWS VPC Resources"
   type        = string
+  default     = "1-tier"
 }
 
 variable "cidr" {
   description = "CIDR block value to define the size of the AWS VPC"
   type        = string
+  default     = "10.0.0.0/20"
 }
 
 variable "subnet_bits" {
   description = "Subnet bits for cidrsubnet interpolation or Size we need to define for the Subnet (cidr of VPC + Subnet bits)"
   type        = string
+  default     = "4"
 }