マルチリージョン 高可用性 / DR構成

import * as cdk from "aws-cdk-lib";
import { Construct } from "constructs";
import * as ec2 from "aws-cdk-lib/aws-ec2";
import * as autoscaling from "aws-cdk-lib/aws-autoscaling";
import * as elbv2 from "aws-cdk-lib/aws-elasticloadbalancingv2";
import * as rds from "aws-cdk-lib/aws-rds";

// 本スタックは Primary(東京) / Secondary(大阪) の各リージョンへデプロイし、
// Aurora Global Database と Route 53 フェイルオーバーで束ねる構成です。
export class MultiRegionHaStack extends cdk.Stack {
  constructor(scope: Construct, id: string, props: cdk.StackProps & { primary: boolean }) {
    super(scope, id, props);

    const vpc = new ec2.Vpc(this, "Vpc", { maxAzs: 2, natGateways: 1 });

    const asg = new autoscaling.AutoScalingGroup(this, "WebAsg", {
      vpc,
      instanceType: new ec2.InstanceType("t3.small"),
      machineImage: ec2.MachineImage.latestAmazonLinux2023(),
      minCapacity: 2,
      maxCapacity: 6,
      vpcSubnets: { subnetType: ec2.SubnetType.PRIVATE_WITH_EGRESS },
    });

    const alb = new elbv2.ApplicationLoadBalancer(this, "Alb", { vpc, internetFacing: true });
    alb.addListener("Http", { port: 80, open: true }).addTargets("Web", { port: 80, targets: [asg] });

    // Aurora Global Database：Primary でグローバルクラスタを作成し、Secondary を関連付け
    new rds.DatabaseCluster(this, "Aurora", {
      engine: rds.DatabaseClusterEngine.auroraPostgres({ version: rds.AuroraPostgresEngineVersion.VER_16_1 }),
      writer: rds.ClusterInstance.serverlessV2("writer"),
      vpc,
      storageEncrypted: true,
    });
    // NOTE: rds.CfnGlobalCluster("multi-region-high-availability-global") を作成し、両リージョンのクラスタを紐付けます。
    // NOTE: route53.CfnRecordSet で failover=(props.primary ? "PRIMARY" : "SECONDARY") と HealthCheck を設定します。
  }
}