Terraformモジュールで再利用可能なインフラを作る

module "<NAME>" {
  source = "<SOURCE>"
  # 設定（入力変数など）
}

variable "cluster_name" {
  description = "クラスターリソースの名前"
  type        = string
}

variable "instance_type" {
  description = "起動するEC2タイプの種類"
  type        = string
}

variable "min_size" {
  description = "EC2インスタンスのASGの最小値"
  type        = number
}

variable "max_size" {
  description = "EC2インスタンスのASGの最大値"
  type        = number
}

variable "db_remote_state_bucket" {
  description = "S3バケットの名前（データベースのリモートステート）"
  type        = string
}

variable "db_remote_state_key" {
  description = "S3でのデータベースのリモートステートのパス"
  type        = string
}

provider "aws" {
  region = "ap-northeast-1"
}

module "webserver_cluster" {
  source = "../../../modules/services/webserver-cluster"

  cluster_name           = "webservers-stage"
  db_remote_state_bucket = "tf-state-backend-20251128"
  db_remote_state_key    = "stage/data-stores/mysql/terraform.tfstate"

  instance_type = "t2.micro"
  min_size      = 2
  max_size      = 2
}

module "webserver_cluster" {
  source = "../../../modules/services/webserver-cluster"

  cluster_name           = "webservers-prod"
  db_remote_state_bucket = "tf-state-backend-20251128"
  db_remote_state_key    = "prod/data-stores/mysql/terraform.tfstate"

  instance_type = "m4.large"  # より大きいインスタンス
  min_size      = 2
  max_size      = 10          # スケールアウト可能
}

locals {
  http_port    = 80
  any_port     = 0
  any_protocol = "-1"
  tcp_protocol = "tcp"
  all_ips      = ["0.0.0.0/0"]
}

resource "aws_security_group_rule" "allow_http_inbound" {
  type              = "ingress"
  security_group_id = aws_security_group.alb.id
  from_port         = local.http_port  # 80
  to_port           = local.http_port
  protocol          = local.tcp_protocol
  cidr_blocks       = local.all_ips
}

output "asg_name" {
  value       = aws_autoscaling_group.example.name
  description = "The name of the Auto Scaling Group"
}

output "alb_security_group_id" {
  value       = aws_security_group.alb.id
  description = "ALBのセキュリティグループID"
}

resource "aws_autoscaling_schedule" "scale_out_during_business_hours" {
  scheduled_action_name  = "scale-out-during-business-hours"
  min_size               = 2
  max_size               = 10
  desired_capacity       = 10
  recurrence             = "0 9 * * *"  # 毎日9時

  autoscaling_group_name = module.webserver_cluster.asg_name  # 出力を参照
}

# Before（動かない）
user_data = base64encode(templatefile("user-data.sh", { ... }))

# After（正しく動く）
user_data = base64encode(templatefile("${path.module}/user-data.sh", { ... }))

resource "aws_security_group" "alb" {
  name = "${var.cluster_name}-alb"

  ingress {  # リソース内に直接書く
    from_port   = 80
    to_port     = 80
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }
}

resource "aws_security_group" "alb" {
  name = "${var.cluster_name}-alb"
}

resource "aws_security_group_rule" "allow_http" {
  type              = "ingress"
  security_group_id = aws_security_group.alb.id
  from_port         = 80
  to_port           = 80
  protocol          = "tcp"
  cidr_blocks       = ["0.0.0.0/0"]
}

# live/stage/main.tf - テスト用ポートを追加
resource "aws_security_group_rule" "allow_testing" {
  type              = "ingress"
  security_group_id = module.webserver_cluster.alb_security_group_id
  from_port         = 12345
  to_port           = 12345
  protocol          = "tcp"
  cidr_blocks       = ["0.0.0.0/0"]
}

git tag -a "v0.0.1" -m "First release"
git push --follow-tags

# stage: 新バージョンをテスト
source = "github.com/user/modules//services/webserver-cluster?ref=v0.0.2"

# prod: 安定版を維持
source = "github.com/user/modules//services/webserver-cluster?ref=v0.0.1"