[Terraform]RDS拡張モニタリングのメトリクスをCloudWatchで可視化する

# ---------------------------------------------
# RDS
# ---------------------------------------------
resource "aws_db_instance" "sqlserver_example" {
  identifier        = "mydb-sqlserver-instance"
  # SQL Server Express Edition
  engine            = "sqlserver-ex"
  # 使用したいバージョンに適宜変更してください
  engine_version    = "16.00.4131.2.v1"
　　　　# SQL Serverに適したインスタンスクラス
  instance_class    = "db.t3.micro"
  allocated_storage = 20
  storage_type      = "gp2"
  # 任意のユーザ名
  username          = "XXX"
  # 任意のパスワード
  password          = "XXX"
  license_model     = "license-included"

  # 拡張モニタリングの設定
  monitoring_interval = 60 # 60秒間隔でモニタリング
  monitoring_role_arn = aws_iam_role.rds_monitoring_role.arn

  # SQL Server固有の設定
  port     = 1433
  timezone = "Tokyo Standard Time"

  db_subnet_group_name   = aws_db_subnet_group.rds.name
  vpc_security_group_ids = [aws_security_group.rds.id]

  # マルチAZ設定
  multi_az = false

  # メンテナンスウィンドウ
  maintenance_window = "Sun:20:00-Sun:22:00"

  # パラメータグループとオプショングループ
  parameter_group_name = "default.sqlserver-ex-16.0"
  option_group_name    = "default:sqlserver-ex-16-00"
}

# ---------------------------------------------
# 拡張モニタリング用IAMロール
# ---------------------------------------------
resource "aws_iam_role" "rds_monitoring_role" {
  name = "rds-monitoring-role"
  assume_role_policy = jsonencode({
    Version = "2012-10-17"
    Statement = [
      {
        Action = "sts:AssumeRole"
        Effect = "Allow"
        Principal = {
          Service = "monitoring.rds.amazonaws.com"
        }
      }
    ]
  })
}

resource "aws_iam_role_policy_attachment" "rds_monitoring_policy" {
  role       = aws_iam_role.rds_monitoring_role.name
  policy_arn = "arn:aws:iam::aws:policy/service-role/AmazonRDSEnhancedMonitoringRole"
}

{
    "engine": "SqlServer",
    "instanceID": "mydb-sqlserver-instance",
    "instanceResourceID": "db-XXXX",
    "timestamp": "2024-08-10T14:26:21Z",
    "version": 1,
    "uptime": "0 days, 02:04:16",
    "numVCPUs": 2,
    "cpuUtilization": {
        "idle": 68.72,
        "kern": 8.74,
        "user": 22.54
    },
    "memory": {
        "commitTotKb": 1548652,
        "commitLimitKb": 2067996,
        "commitPeakKb": 1794628,
        "physTotKb": 1019420,
      　　　　// ★今回可視化するメトリクス
        "physAvailKb": 58648,
        "sysCacheKb": 56596,
        "kernTotKb": 272036,
        "kernPagedKb": 151552,
        "kernNonpagedKb": 120484,
        "sqlServerTotKb": 127336,
        "pageSize": 4096
    },
		// その他要素...
}

$.instanceID = "${aws_db_instance.sqlserver_example.identifier}" && $.memory.physAvailKb > 0

# ---------------------------------------------
# メトリクスフィルター（OS利用可能なメモリ）
# ---------------------------------------------
resource "aws_cloudwatch_log_metric_filter" "rds_os_available_memory" {
  name           = "RDSMemoryUsed-${aws_db_instance.sqlserver_example.identifier}"
  pattern        = <<PATTERN
{ $.instanceID = "${aws_db_instance.sqlserver_example.identifier}" && $.memory.physAvailKb > 0 }
PATTERN
  log_group_name = "RDSOSMetrics"

  metric_transformation {
    name      = "PhysicalAvailableMemory"
    namespace = "CustomRDSMetrics"
    value     = "$.memory.physAvailKb"
    unit      = "Kilobytes"
  }
}