在AWS CDK应用程序中，可以使用Lamnda函数以及CloudFormation生命周期事件钩子来解决此问题。以下是一些代码示例，用于向AWS CDK自动缩放组添加Lifecycle Hook，以便在初始启动时发送通知：

import * as lambda from '@aws-cdk/aws-lambda';
import * as autoscaling from '@aws-cdk/aws-autoscaling';
import * as cdk from '@aws-cdk/core';

const app = new cdk.App();

const asg = new autoscaling.AutoScalingGroup(app, 'MyASG', {
  instanceType: new InstanceType('t2.micro'),
  machineImage: new AmazonLinuxImage(),
  maxCapacity: 4,
  minCapacity: 1,
});

// Create the Lambda function that will receive the notification
const lifecycleHookFn = new lambda.Function(this, 'LifecycleHookFn', {
  runtime: lambda.Runtime.NODEJS_12_X,
  code: lambda.Code.fromInline('console.log(event);'),
  handler: 'index.handler',
});

// Add the lifecycle hook to the Auto Scaling Group
asg.addLifecycleHook('MyLifecycleHook', {
  defaultResult: autoscaling.DefaultResult.CONTINUE,
  heartbeatTimeout: cdk.Duration.minutes(5),
  lifecycleTransition: autoscaling.LifecycleTransition.INSTANCE_LAUNCHING,
  notificationTarget: new lambda.LambdaTarget(lifecycleHookFn),
  role: new iam.Role(asg, 'MyLifecycleHookRole', {
    assumedBy: new iam.ServicePrincipal('cloudformation.amazonaws.com'),
    inlinePolicies: {
      CfnDoNotDeletePolicy: new iam.PolicyDocument({
        statements: [
          new iam.PolicyStatement({
            actions: [
              'autoscaling:CompleteLifecycleAction',
            ],
            resources: ['*'],
          }),
        ],
      }),
    },
  }),
});

这将向Auto Scaling Group添加Lifecycle Hook，该挂钩将通知Lambda函数在Auto Scaling Group启动实例时。在此示例中，Lambda函数只是简单地记录传递给它的事件。你可以根据自己的需求