Creating an Amazon ECS Service with AutoScaling and expose it using an Application Load Balancer

import * as ecs_patterns from 'aws-cdk-lib/aws-ecs-patterns';
import * as elbv2 from 'aws-cdk-lib/aws-elasticloadbalancingv2';
import { Duration } from 'aws-cdk-lib';

    const sg_service = new ec2.SecurityGroup(this, 'MySGService', { vpc: vpc });
    sg_service.addIngressRule(ec2.Peer.ipv4('0.0.0.0/0'), ec2.Port.tcp(3000));
    
    const service = new ecs.FargateService(this, 'Service', {
      cluster,
      taskDefinition: fargateTaskDefinition,
      desiredCount: 2,
      assignPublicIp: false,
      securityGroups: [sg_service]
    });
    
    // Setup AutoScaling policy
    const scaling = service.autoScaleTaskCount({ maxCapacity: 6, minCapacity: 2 });
    scaling.scaleOnCpuUtilization('CpuScaling', {
      targetUtilizationPercent: 50,
      scaleInCooldown: Duration.seconds(60),
      scaleOutCooldown: Duration.seconds(60)
    });

    const lb = new elbv2.ApplicationLoadBalancer(this, 'ALB', {
      vpc,
      internetFacing: true
    });

    const listener = lb.addListener('Listener', {
      port: 80,
    });

    listener.addTargets('Target', {
      port: 80,
      targets: [service],
      healthCheck: { path: '/api/' }
    });

    listener.connections.allowDefaultPortFromAnyIpv4('Open to the world');

cdk synth

cdk deploy