AWS CDK - Launch an EC2 Autoscaling Group with userdata read of disk

cdk-asg-userdata.ts

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

    // Security group
    const webSg = new ec2.SecurityGroup(this, 'WebSG',{
      vpc: vpc,
      allowAllOutbound: true,
      description: "Web Server Security Group"
    });
    webSg.addIngressRule(ec2.Peer.anyIpv4(), ec2.Port.tcp(8080), 'Web from anywhere')

    // ASG Configuration
    const asg = new autoscaling.AutoScalingGroup(this, 'ASG', {
      vpc: vpc,
      instanceType: ec2.InstanceType.of(ec2.InstanceClass.BURSTABLE2, ec2.InstanceSize.MICRO),
      machineImage: new ec2.AmazonLinuxImage(), // get the latest Amazon Linux image
      maxCapacity: 5,
      minCapacity: 1,
      desiredCapacity: 3,
      role: instanceRole
    });

    // Add user Data
    var bootscript:string;
    bootscript = fs.readFileSync('assets/userdata.sh','utf8');

    asg.addUserData(bootscript);
    asg.addSecurityGroup(webSg)