Terraform_Snippets/module/main.tf

variable "ebs_kms_key" { default = null}

variable "mongo_disk_size_default" { default = 100}
variable "mongo_disk_size" { default = null}

variable "mongo_disk_type_default" { default = 100}
variable "mongo_disk_type" { default = null}

variable "mongo_disk_encryption" { default = null}
variable "mongo_disk_kms_key" { default = null}

variable "mongo_mount_default" { default = "mongo"}
variable "mongo_device_name" { default = "/dev/sdh"}

variable "mysql_disk_size" { default = null}
variable "ifs_disk_size" { default = null}

variable "num_instances" { default = 2}
variable "enable_mysql" { default = false}
variable "enable_mongo" { default = false}
variable "enable_ifs" { default = false}

provider "aws" {
  version = "~> 2.0"
  region  = "us-east-2"
}

resource "aws_instance" "test" {
  count = var.num_instances
  ami           = "ami-05c1fa8df71875112"
  instance_type = "t2.micro"
  availability_zone = "us-east-2a"
  tags = {
    Name = "test${count.index}"
    Count = count.index
  }
}

resource "aws_ebs_volume" "mongo" {
  count = var.enable_mongo == true ? var.num_instances : 0
  availability_zone = "us-east-2a"
  size =  var.mongo_disk_size != null ? var.mongo_disk_size : var.mongo_disk_size_default
  encrypted = var.mongo_disk_encryption != null ? var.mongo_disk_size[count.index] : true
  type = var.mongo_disk_type != null ? var.mongo_disk_size[count.index] : var.mongo_disk_type_default
  kms_key_id = var.mongo_disk_kms_key != null ? var.mongo_disk_kms_key : var.ebs_kms_key
  tags = {
    Name = "Mongo${count.index}"
    Count = count.index
    Mount = "mongo"
  }
}

resource "aws_volume_attachment" "mongo_att" {
  count = var.enable_mongo == true ? var.num_instances : 0
  device_name = var.mongo_device_name
  volume_id   = aws_ebs_volume.mongo[count.index].id
  instance_id = aws_instance.test[count.index].id
}