aws-lambda - Lambda 函数完成后 Amazon Cloudformation 堆栈挂起

Question

我有一个简单的模板来创建 S3 存储桶，然后调用 Lambda 函数将对象从公共(public)存储桶复制到其中:

AWSTemplateFormatVersion: 2010-09-09
Transform: AWS::Serverless-2016-10-31
Description: Create an S3 Bucket, populate it with a copy of a sample CSV file
Parameters:
  bucketname:
    Type: String
    Description: Name of bucket where the CSV file will be bootstrapped, bucket names MUST be unique across AWS and no Upper Case characters - 8 or more characters
    MinLength: 8
Outputs:
  bucketURL:
    Value:
      Fn::Join:
        - ''
        - - 'https://s3.amazonaws.com/'
          - !Ref bucketname
Resources:
  S3Bucket:
    Type: AWS::S3::Bucket
    DeletionPolicy: Retain
    Properties:
      BucketName: !Ref bucketname
  deploytos3:
    Type: AWS::Serverless::Function
    Properties:
      Handler: index.handler
      Runtime: nodejs12.x
      CodeUri: 's3://mongodb-aws-jam/lambdaDeploy.zip'
      Policies:
        - AWSLambdaBasicExecutionRole
        - AmazonS3FullAccess
  DeploymentCustomResource:
    Type: Custom::deploytos3
    Properties:
      ServiceToken: !GetAtt deploytos3.Arn
      bucketname: !Ref bucketname

这是 Lambda 函数:

const AWS = require('aws-sdk');
var response = require('cfn-response');

const s3 = new AWS.S3();
const srcBucket = "mongodb-aws-jam"
const srcKey = "SampleData.csv"

exports.handler = async (event, context) => {
    console.log("start")
    myBucket = event.ResourceProperties['bucketname']
    console.log(`Will bootstrap ${srcKey} object in ${myBucket} bucket`)

    const copyparams = {
        Bucket : myBucket,
        CopySource : `/${srcBucket}/${srcKey}`,
        Key : srcKey
    };

    try {
        await s3.copyObject(copyparams).promise();
    } catch (error) {
        const errorText = `Failed to copy file to ${myBucket}/${srcKey}: error`
        console.log(errorText)
        // callback(null, {statusCode: 500, body: errorText})
        response.send(event, context, response.FAILED, {Error: errorText})
        return
    }
    resultText = `Copied file to ${myBucket}/${srcKey}`
    console.log(resultText)
    // callback(null, {statusCode: 200, body: resultText})
    response.send(event, context, response.SUCCESS, {})
};

堆栈成功创建并引导新存储桶，但堆栈历史记录显示 DeploymentCustomResource 资源从未超过 CREATE_IN_PROGRESS 状态，即使 lambda 日志显示该功能成功完成。我尝试了使用回调的各种替代方法，并将函数减少到不执行任何工作，但堆栈总是挂起。

有什么建议吗？

Answer 1

由于 CloudFormation (CFN) 等待函数的正确响应，您的函数陷入 CREATE_IN_PROGRESS 状态。您的代码没有提供它。

自定义资源的函数需要特殊设计。必须正确处理CFN事件，并做出相应的响应。

对于nodejs中的函数，您可以使用辅助库 cfn-response，如cfn-response module所示。 Nodejs 中自定义资源函数的示例为 here .