既存の Route 53 ホストゾーンのドメイン名を使って ALB にアクセスする構成を AWS CDK で構築してみた

import {
  aws_certificatemanager as acm,
  aws_route53 as route53,
  aws_ec2 as ec2,
  aws_elasticloadbalancingv2 as elbv2,
  aws_route53_targets as route53Targets,
  Stack,
  StackProps,
} from 'aws-cdk-lib';
import { Construct } from 'constructs';

export class CdkSampleStack extends Stack {
  constructor(scope: Construct, id: string, props: StackProps) {
    super(scope, id, props);

    /**
     * 環境変数からドメイン名を取得
     */
    const domainName = process.env.DOMAIN_NAME || 'example.com';

    /**
     * 既存のホストゾーンを取得
     */
    const hostedZone = route53.HostedZone.fromLookup(this, 'HostedZone', {
      domainName,
    });

    /**
     * ACM 証明書を作成
     */
    const certificate = new acm.Certificate(this, 'Certificate', {
      domainName,
      validation: acm.CertificateValidation.fromDns(hostedZone),
    });

    /**
     * VPC を作成
     */
    const vpc = new ec2.Vpc(this, 'Vpc');

    /**
     * ALB を作成
     */
    const loadBalancer = new elbv2.ApplicationLoadBalancer(
      this,
      'LoadBalancer',
      {
        vpc,
        internetFacing: true,
      }
    );

    /**
     * 証明書を紐付けたリスナーを作成
     */
    loadBalancer.addListener('Listener', {
      port: 443,
      certificates: [certificate],
      defaultAction: elbv2.ListenerAction.fixedResponse(200, {
        contentType: 'text/plain',
        messageBody: 'Hello, CDK!',
      }),
    });

    /**
     * ホストゾーンに ALB の DNS 名をエイリアス登録
     */
    new route53.ARecord(this, 'AliasRecord', {
      zone: hostedZone,
      target: route53.RecordTarget.fromAlias(
        new route53Targets.LoadBalancerTarget(loadBalancer)
      ),
    });
  }
}

{
  "availability-zones:account=XXXXXXXXXXXX:region=ap-northeast-1": [
    "ap-northeast-1a",
    "ap-northeast-1c",
    "ap-northeast-1d"
  ],
  "hosted-zone:account=XXXXXXXXXXXX:domainName=ZZZZZZZZZZZZ:region=ap-northeast-1": {
    "Id": "/hostedzone/YYYYYYYYYYYYYYYY",
    "Name": "ZZZZZZZZZZZZ",
  }
}

$ curl https://${DOMAIN_NAME}
Hello, CDK!

$ npx cdk synth
（中略）

Error: Cannot retrieve value from context provider hosted-zone since account/region are not specified at the stack level. Configure "env" with an account and region when you define your stack.See https://docs.aws.amazon.com/cdk/latest/guide/environments.html for more details.

import { App } from 'aws-cdk-lib';
import { CdkSampleStack } from '../lib/cdk-sample-stack';

const app = new App();

new CdkSampleStack(app, 'CdkSampleStack', {
  /**
   * 環境変数からリージョンとアカウント ID を取得
   *
   * MEMO: ホストゾーンの Lookup にはリージョンおよびアカウント ID の指定が必要
   */
  env: {
    region: process.env.CDK_DEFAULT_REGION,
    account: process.env.CDK_DEFAULT_ACCOUNT,
  },
});