Cloudformation CustomResource“响应不是有效的 JSON”

问题描述

我第一次尝试实现 Custom Resource。每当我尝试部署包含堆栈时，自定义资源的创建都会失败并显示“响应不是有效的 JSON”，但我不知道为什么。

import json
import os
import requests

import logging
# https://stackoverflow.com/questions/37703609
log = logging.getLogger(__name__)
log.setLevel(logging.DEBUG)


def handler(event,context):
    try:
        log.debug(f'DEBUG - called!')
        log.info(f'Event: {event}')
        if event['RequestType'] in ['Create','Update']:
          pass
          # I _will_ have logic here eventually - when this is working!
        else:
            log.info('Non-create/update RequestType')

        # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/crpg-ref-responses.html
        responseData = dict(
            {
                'Status': 'SUCCESS','PhysicalResourceId': event['PhysicalResourceId']
                    if 'PhysicalResourceId' in event
                    else context.log_stream_name
            },**{key: event[key] for key in
               ['StackId','RequestId','LogicalResourceId']}
        )
        log.debug(f'Response data: {responseData}')
        requests.put(event['ResponseURL'],data=responseData)
    except Exception as e:
        log.error(f'Lambda Failed! {e}')
        # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/crpg-ref-responses.html
        responseData = dict(
            {
                'Status': 'Failed','Reason': f'See logs in {context["logStreamName"]}','PhysicalResourceId': event['PhysicalResourceId']
                    if 'PhysicalResourceId' in event
                    else context.log_stream_name,},**{key: event.get(key,'') for key in
               ['StackId',data=responseData)

下面是来自创建/删除循环的一些示例日志消息：

START RequestId: f151f270-acc6-4cff-b4c0-0eafaf4e5fef Version: $LATEST
[DEBUG] 2021-03-22T19:29:09.33Z f151f270-acc6-4cff-b4c0-0eafaf4e5fef    DEBUG - called!
[INFO]  2021-03-22T19:29:09.33Z f151f270-acc6-4cff-b4c0-0eafaf4e5fef    Event: {'RequestType': 'Create','Servicetoken': 'arn:aws:lambda:us-east-1:119281758091:function:prod-stage-ApplicationSta-FetchCommitHistoryFuncti-T7Z15V6TDZSO','ResponseURL': 'https://cloudformation-custom-resource-response-useast1.s3.amazonaws.com/arn%3Aaws%3Acloudformation%3Aus-east-1%3A119281758091%3Astack/prod-stage-ApplicationStack/94d24fa0-8b44-11eb-a285-0ec6977a61f1%7CFetchCommitsCustomresource%7C1d80a8f0-f72c-4e50-8039-6c0509dd24ee?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20210322T192907Z&X-Amz-SignedHeaders=host&X-Amz-Expires=7200&X-Amz-Credential=AKIA6L7Q4OWT3GW5BT7K%2F20210322%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=4cc0d2590330f42e8928bdfc2bf5a30c31bfb6228d681e11acf25ef17b8dde2c','StackId': 'arn:aws:cloudformation:us-east-1:119281758091:stack/prod-stage-ApplicationStack/94d24fa0-8b44-11eb-a285-0ec6977a61f1','RequestId': '1d80a8f0-f72c-4e50-8039-6c0509dd24ee','LogicalResourceId': 'FetchCommitsCustomresource','ResourceType': 'AWS::CloudFormation::Customresource','ResourceProperties': {'Servicetoken': 'arn:aws:lambda:us-east-1:119281758091:function:prod-stage-ApplicationSta-FetchCommitHistoryFuncti-T7Z15V6TDZSO'}}
[DEBUG] 2021-03-22T19:29:09.293Z    f151f270-acc6-4cff-b4c0-0eafaf4e5fef    Response data: {'Status': 'SUCCESS','PhysicalResourceId': '2021/03/22/[$LATEST]8801d1d794c04d25ad31fa43223cbe93','LogicalResourceId': 'FetchCommitsCustomresource'}
END RequestId: f151f270-acc6-4cff-b4c0-0eafaf4e5fef
REPORT RequestId: f151f270-acc6-4cff-b4c0-0eafaf4e5fef  Duration: 444.73 ms Billed Duration: 445 ms Memory Size: 128 MB Max Memory Used: 61 MB  Init Duration: 463.55 ms    
START RequestId: 616f7c98-1d76-4459-96d3-6257c5620a99 Version: $LATEST
[DEBUG] 2021-03-22T19:29:20.640Z    616f7c98-1d76-4459-96d3-6257c5620a99    DEBUG - called!
[INFO]  2021-03-22T19:29:20.640Z    616f7c98-1d76-4459-96d3-6257c5620a99    Event: {'RequestType': 'Delete','ResponseURL': 'https://cloudformation-custom-resource-response-useast1.s3.amazonaws.com/arn%3Aaws%3Acloudformation%3Aus-east-1%3A119281758091%3Astack/prod-stage-ApplicationStack/94d24fa0-8b44-11eb-a285-0ec6977a61f1%7CFetchCommitsCustomresource%7C85da252d-1d0d-4fe5-84eb-755f1e6dc646?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20210322T192920Z&X-Amz-SignedHeaders=host&X-Amz-Expires=7200&X-Amz-Credential=AKIA6L7Q4OWT3GW5BT7K%2F20210322%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=0bd2e0a28783980b9014289cd852bf02252cdf5cd11f4405d00707002e6e39e9','RequestId': '85da252d-1d0d-4fe5-84eb-755f1e6dc646','PhysicalResourceId': 'prod-stage-ApplicationStack-FetchCommitsCustomresource-1VTI0Q0VKIJDM','ResourceProperties': {'Servicetoken': 'arn:aws:lambda:us-east-1:119281758091:function:prod-stage-ApplicationSta-FetchCommitHistoryFuncti-T7Z15V6TDZSO'}}
[INFO]  2021-03-22T19:29:20.640Z    616f7c98-1d76-4459-96d3-6257c5620a99    Non-create/update RequestType
[DEBUG] 2021-03-22T19:29:20.640Z    616f7c98-1d76-4459-96d3-6257c5620a99    Response data: {'Status': 'SUCCESS','LogicalResourceId': 'FetchCommitsCustomresource'}
END RequestId: 616f7c98-1d76-4459-96d3-6257c5620a99
REPORT RequestId: 616f7c98-1d76-4459-96d3-6257c5620a99  Duration: 174.97 ms Billed Duration: 175 ms Memory Size: 128 MB Max Memory Used: 61 MB

JSON 对我来说似乎是有效的（特别是 PhysicalResourceId 是非空的，这是我第一次仅使用 event['PhysicalResourceId'] 获取它时的问题。有什么问题？

解决方法

我认为您可能需要将字典转换为 requests.put 中的 json 字符串。

尝试类似：

requests.put(event['ResponseURL'],data=json.dumps(responseData))

amazon-cloudformation amazon-web-services aws-cloudformation-custom-resource