AWS Lambda 関数 から RDS Data API による Aurora データベースへのアクセスを X-Ray で可視化する

import serverlessExpress from "@codegenie/serverless-express";
import cors from "cors";
import express, { Request, Response } from "express";
import {
  RDSDataClient,
  ExecuteStatementCommand,
} from "@aws-sdk/client-rds-data";
import { captureAWSv3Client } from "aws-xray-sdk";

const app = express();
app.use(cors());
app.use(express.json());

// 環境変数の取得
const DATABASE_NAME = process.env.DATABASE_NAME;
const CLUSTER_ARN = process.env.CLUSTER_ARN;
const SECRET_ARN = process.env.SECRET_ARN;

// RDS Data API クライアントの初期化
const rdsDataClient = captureAWSv3Client(new RDSDataClient({})); // captureAWSv3Client を使うことで X-Ray によるトレースを有効化

app.get("/hello", async (_: Request, res: Response): Promise<void> => {
  try {
    // テーブルのカウントを取得するだけのクエリを実行
    const command = new ExecuteStatementCommand({
      resourceArn: CLUSTER_ARN,
      secretArn: SECRET_ARN,
      database: DATABASE_NAME,
      sql: "SELECT COUNT(*) as table_count FROM information_schema.tables",
    });

    // 1回目のクエリ実行
    const result = await rdsDataClient.send(command);

    // カウント結果を取得
    const tableCount = result.records?.[0]?.[0]?.longValue || 0;

    res.status(200).json({
      table_count: tableCount,
    });
  } catch (error) {
    console.error("Error counting tables:", error);
    res.status(500).json({
      error: "Internal server error",
      message: "Failed to count tables",
    });
  }
});

export const handler = serverlessExpress({ app });

import * as cdk from "aws-cdk-lib";
import * as apigateway from "aws-cdk-lib/aws-apigateway";
import * as lambda_nodejs from "aws-cdk-lib/aws-lambda-nodejs";
import * as aws_lambda from "aws-cdk-lib/aws-lambda";
import * as rds from "aws-cdk-lib/aws-rds";
import * as ec2 from "aws-cdk-lib/aws-ec2";
import { Construct } from "constructs";

export class MainStack extends cdk.Stack {
  constructor(scope: Construct, id: string) {
    super(scope, id);

    const DEFAULT_DATABASE_NAME = "mydatabase";

    /**
     * VPC の作成
     */
    const vpc = new ec2.Vpc(this, "VPC", {
      subnetConfiguration: [
        {
          cidrMask: 24,
          name: "PrivateIsolated",
          subnetType: ec2.SubnetType.PRIVATE_ISOLATED,
        },
      ],
      natGateways: 0,
      restrictDefaultSecurityGroup: true,
    });

    /**
     * RDS Aurora PostgreSQL クラスターの作成
     */
    const auroraCluster = new rds.DatabaseCluster(this, "AuroraCluster", {
      engine: rds.DatabaseClusterEngine.auroraPostgres({
        version: rds.AuroraPostgresEngineVersion.VER_17_4,
      }),
      writer: cdk.aws_rds.ClusterInstance.serverlessV2("Writer"),
      vpc,
      vpcSubnets: {
        subnetType: ec2.SubnetType.PRIVATE_ISOLATED,
      },
      defaultDatabaseName: DEFAULT_DATABASE_NAME,
      removalPolicy: cdk.RemovalPolicy.DESTROY,
    });

    /**
     * Lambda-lith 関数ハンドラー
     */
    const handler = new lambda_nodejs.NodejsFunction(this, "Handler", {
      entry: "src/rest-api-router.ts",
      tracing: aws_lambda.Tracing.ACTIVE, // AWS X-Ray によるトレースを有効化
      environment: {
        DATABASE_NAME: DEFAULT_DATABASE_NAME,
        CLUSTER_ARN: auroraCluster.clusterArn,
        SECRET_ARN: auroraCluster.secret?.secretArn || "",
      },
    });
    auroraCluster.grantDataApiAccess(handler); // Lambda 関数に RDS Data API アクセス権限を付与

    /**
     * API Gateway REST API
     */
    new apigateway.LambdaRestApi(this, "RestApi", {
      handler,
      deployOptions: {
        tracingEnabled: true, // AWS X-Ray によるトレースを有効化
      },
    });
  }
}

$ curl https://jaezq1ier7.execute-api.ap-northeast-1.amazonaws.com/prod/hello
{"table_count":200}