8. 2 つ目の EC2 インスタンスを ELB に登録

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作成

• 作成者： moritalous
• 作成日： 2023/08/14

参照元：8. 2 つ目の EC2 インスタンスを ELB に登録

追加したEC2をELBの配下に登録します。

listener.addTargets('instance', {
  targets: [
    new targets.InstanceTarget(instance),
    new targets.InstanceTarget(instance2)
    ],
  port: 80,
  healthCheck: {
    path: '/wp-includes/images/blank.gif'
  }
})
    
instance.connections.allowFrom(loadBalancer, ec2.Port.tcp(80))
instance2.connections.allowFrom(loadBalancer, ec2.Port.tcp(80))

注記

セキュリティグループの設定ですが、プログラミング言語的にこのような記述も可能です。

const instances: ec2.IInstance[] = [instance, instance2]
instances.forEach((i) => i.connections.allowFrom(loadBalancer, ec2.Port.tcp(80)))

課題

ELBに2台目のEC2を登録してください。

回答

bin/handson-cdk.ts

import * as cdk from "aws-cdk-lib";
import { Construct } from "constructs";
// import * as sqs from 'aws-cdk-lib/aws-sqs';
import * as ec2 from "aws-cdk-lib/aws-ec2";
import { Asset } from 'aws-cdk-lib/aws-s3-assets';
import * as rds from "aws-cdk-lib/aws-rds";
import * as elb from "aws-cdk-lib/aws-elasticloadbalancingv2";
import * as targets from 'aws-cdk-lib/aws-elasticloadbalancingv2-targets';

export class HandsonCdkStack extends cdk.Stack {
  constructor(scope: Construct, id: string, props?: cdk.StackProps) {
    super(scope, id, props);

    // The code that defines your stack goes here

    // example resource
    // const queue = new sqs.Queue(this, 'HandsonCdkQueue', {
    //   visibilityTimeout: cdk.Duration.seconds(300)
    // });

    const vpc = new ec2.Vpc(this, "VPC", {
      natGateways: 0,
    });
    
    const instance = new ec2.Instance(this, 'EC2Instance', {
      vpc: vpc, 
      instanceType: ec2.InstanceType.of(ec2.InstanceClass.T2, ec2.InstanceSize.MICRO),
      machineImage: ec2.MachineImage.latestAmazonLinux2023(),

      vpcSubnets: {
        subnetType: ec2.SubnetType.PUBLIC
      },
      
      associatePublicIpAddress: true,
      
      instanceName: 'webserver1-user1',
      
    })

    instance.connections.allowFromAnyIpv4(ec2.Port.tcp(80))
    
    const asset = new Asset(this, 'Asset', {
      path: './asset/install_wordpress.sh'
    })
    
    const localPath = instance.userData.addS3DownloadCommand({
      bucket: asset.bucket,
      bucketKey: asset.s3ObjectKey
    })
    
    instance.userData.addExecuteFileCommand({
      filePath: localPath
    })
    
    asset.grantRead(instance.role)
    
    new cdk.CfnOutput(this, 'EC2PublicIP', {
      value: instance.instancePublicIp
    })

    const instance2 = new ec2.Instance(this, 'EC2Instance2', {
      vpc: vpc, 
      instanceType: ec2.InstanceType.of(ec2.InstanceClass.T2, ec2.InstanceSize.MICRO),
      machineImage: ec2.MachineImage.genericLinux({
        "ap-northeast-1": "ami-066ce4a60894618ce"
      }),

      vpcSubnets: {
        subnetType: ec2.SubnetType.PUBLIC
      },
      
      associatePublicIpAddress: true,
      
      instanceName: 'webserver2-user1',
      
    })
    
    const rdsInstance = new rds.DatabaseInstance(this, 'RdsDBInstance', {
      vpc: vpc,
      engine: rds.DatabaseInstanceEngine.MYSQL,
      instanceType: ec2.InstanceType.of(ec2.InstanceClass.T2, ec2.InstanceSize.MICRO),
      
      databaseName: 'wordpress',
      
      vpcSubnets: {
        subnetType: ec2.SubnetType.PRIVATE_ISOLATED
      },
    })
    
    rdsInstance.connections.allowDefaultPortFrom(instance)
    rdsInstance.connections.allowDefaultPortFrom(instance2)
    
    new cdk.CfnOutput(this, 'RDSDomainName', {
      value: rdsInstance.dbInstanceEndpointAddress
    })

    const loadBalancer = new elb.ApplicationLoadBalancer(this, 'ELB', {
      vpc: vpc,
      internetFacing: true,
    })

    const listener = loadBalancer.addListener('Listener', {
      port: 80
    })
    
    listener.addTargets('instance', {
      targets: [
        new targets.InstanceTarget(instance),
        new targets.InstanceTarget(instance2)
        ],
      port: 80,
      healthCheck: {
        path: '/wp-includes/images/blank.gif'
      }
    })
    
    instance.connections.allowFrom(loadBalancer, ec2.Port.tcp(80))
    instance2.connections.allowFrom(loadBalancer, ec2.Port.tcp(80))
    
    new cdk.CfnOutput(this, 'ELBDomainName', {
      value: loadBalancer.loadBalancerDnsName
    })

  }
}