AWS Lambda：没有名为“ cfnresponse”的模块

Question

我已经部署了一个AWS Lambda，其中包含：

import json
import boto3
import cfnresponse
import urllib.request
from botocore.exceptions import ClientError

def lambda_handler(event, context):
...
cfnresponse.send(event, context, status, responseData, "CustomResourcePhysicalID")

我试图cfnresponse在我的cloudformations中获取的值：

Resources:
  API:
    Type: Custom::API
    Version: '1.0'
    Properties:
      ServiceToken: arn:aws:lambda:eu-west-1:1234567891011:function:getCountry
Outputs:
  Status:
    Value:
       !GetAtt API.Data

现在，cfn卡住了，我得到了错误：

Unable to import module 'lambda_function': No module named 'cfnresponse' 

我究竟做错了什么？当我检查文档时，似乎是这样做的方法。

Answer 1

您是否在 中指定了函数的源代码ZipFile？如果您指定实际的 zip 文件，则不会包含该模块。

当您使用ZipFile属性指定函数的源代码并且该函数与 AWS CloudFormation 自定义资源交互时，您可以加载 cfn-response 模块以向这些资源发送响应。该模块包含一个 send 方法，该方法通过 Amazon S3 预签名 URL（ResponseURL）将响应对象发送到自定义资源。

如果您需要使用实际的 zip 文件，或者由于任何其他原因这不起作用，您可以自己包含该模块。它的源代码可在您提供的链接中找到。对于 Python 3，它是：

#  Copyright 2016 Amazon Web Services, Inc. or its affiliates. All Rights Reserved.
#  This file is licensed to you under the AWS Customer Agreement (the "License").
#  You may not use this file except in compliance with the License.
#  A copy of the License is located at http://aws.amazon.com/agreement/ .
#  This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, express or implied.
#  See the License for the specific language governing permissions and limitations under the License.

from botocore.vendored import requests
import json

SUCCESS = "SUCCESS"
FAILED = "FAILED"

def send(event, context, responseStatus, responseData, physicalResourceId=None, noEcho=False):
    responseUrl = event['ResponseURL']

    print(responseUrl)

    responseBody = {}
    responseBody['Status'] = responseStatus
    responseBody['Reason'] = 'See the details in CloudWatch Log Stream: ' + context.log_stream_name
    responseBody['PhysicalResourceId'] = physicalResourceId or context.log_stream_name
    responseBody['StackId'] = event['StackId']
    responseBody['RequestId'] = event['RequestId']
    responseBody['LogicalResourceId'] = event['LogicalResourceId']
    responseBody['NoEcho'] = noEcho
    responseBody['Data'] = responseData

    json_responseBody = json.dumps(responseBody)

    print("Response body:\n" + json_responseBody)

    headers = {
        'content-type' : '',
        'content-length' : str(len(json_responseBody))
    }

    try:
        response = requests.put(responseUrl,
                                data=json_responseBody,
                                headers=headers)
        print("Status code: " + response.reason)
    except Exception as e:
        print("send(..) failed executing requests.put(..): " + str(e))

Answer 2

Cfnresponse仅在python 2.7中默认在lambda中可用。可能您正在使用3.6。