Modularisasi Infrastruktur dengan Terraform Modules

modules/
└── aws_web_cluster/
    ├── main.tf       # Resource yang dibuat oleh modul (EC2, SG, dsb)
    ├── variables.tf  # Input yang diwajibkan saat memanggil modul
    ├── outputs.tf    # Nilai yang dikembalikan modul ke pemanggil
    └── README.md     # Dokumentasi cara pakai modul

variable "cluster_name" {
  type        = string
  description = "Nama prefix untuk cluster server"
}

variable "server_count" {
  type        = number
  default     = 2
}

variable "instance_type" {
  type    = string
  default = "t2.micro"
}

variable "subnet_id" {
  type        = string
  description = "ID subnet tempat server akan ditempatkan"
}

resource "aws_instance" "cluster_nodes" {
  count         = var.server_count
  ami           = "ami-0df7a207adb9748c7" # Ubuntu 22.04 LTS
  instance_type = var.instance_type
  subnet_id     = var.subnet_id

  tags = {
    Name = "${var.cluster_name}-node-${count.index + 1}"
  }
}

output "instance_ids" {
  value = aws_instance.cluster_nodes[*].id
}

output "private_ips" {
  value = aws_instance.cluster_nodes[*].private_ip
}

module "dev_web_cluster" {
  source       = "../../modules/aws_web_cluster"
  cluster_name = "dev-app"
  server_count = 1                 # Cukup 1 server murah untuk dev
  instance_type= "t2.nano"
  subnet_id    = "subnet-xxxxxxx"
}

module "prod_web_cluster" {
  source       = "../../modules/aws_web_cluster"
  cluster_name = "prod-app"
  server_count = 5                 # 5 server bertenaga tinggi untuk produksi
  instance_type= "t3.medium"
  subnet_id    = "subnet-yyyyyyy"
}

# Mengambil output dari modul prod:
output "production_ips" {
  value = module.prod_web_cluster.private_ips
}

module "vpc" {
  source  = "terraform-aws-modules/vpc/aws"
  version = "5.1.2"

  name = "enterprise-vpc"
  cidr = "10.0.0.0/16"

  azs             = ["ap-southeast-1a", "ap-southeast-1b"]
  private_subnets = ["10.0.1.0/24", "10.0.2.0/24"]
  public_subnets  = ["10.0.101.0/24", "10.0.102.0/24"]

  enable_nat_gateway = true
  single_nat_gateway = true

  tags = {
    Terraform   = "true"
    Environment = "prod"
  }
}