Lambda execution failed with status 200 due to customer function error: 'name'

Question

我是 AWS 服务的新手。尝试使用 AWS SAM(yaml)、Lambdas 和 API 网关实现简单的 CRUD。面临 POST 方法的问题。 Lambda 本身工作正常，但如果我在 API 网关内尝试它 - 得到：

Lambda execution failed with status 200 due to customer function error: 'name'

这是 Lambda 代码本身：

import json
import boto3
import os


dynamodb = boto3.resource('dynamodb')
table_name = os.environ.get('DYNAMO_TABLE', 'dragons-table')
region = os.environ.get('REGION_NAME', 'us-east-1')
table = dynamodb.Table(table_name)


def lambda_handler(event, context):
    table.put_item(
        Item={
            'name': event['name'],
            'breed': event['breed'],
            'danger_rating': event['danger_rating']
        }
    )
    response = {
        'message': "Item added"
    }
    return {
        "statusCode": 201,
        "body": json.dumps(response),
    }

这是执行后的日志：

Thu Feb 03 10:48:15 UTC 2022 : Endpoint response body before transformations: {"errorMessage": "'name'", "errorType": "KeyError", "requestId": "83fcc181-b4b5-4a6d-b035-4ea12eaa892e", "stackTrace": ["  File \"/var/task/post_dragons.py\", line 13, in lambda_handler\n    name = event['name']\n"]}
Thu Feb 03 10:48:15 UTC 2022 : Lambda execution failed with status 200 due to customer function error: 'name'. Lambda request id: 83fcc181-b4b5-4a6d-b035-4ea12eaa892e
Thu Feb 03 10:48:15 UTC 2022 : Method completed with status: 502

Lambda 代理集成肯定是开启的，所以event 不能为空...

非常感谢您的帮助。谢谢:)

更新：添加 print(event) 后添加了 CloudWatch 日志：

{'resource': '/dragons', 'path': '/dragons', 'httpMethod': 'POST', 'headers': {'Accept': '*/*', 'Accept-Encoding': 'gzip, deflate, br', 'CloudFront-Forwarded-Proto': 'https', 'CloudFront-Is-Desktop-Viewer': 'true', 'CloudFront-Is-Mobile-Viewer': 'false', 'CloudFront-Is-SmartTV-Viewer': 'false', 'CloudFront-Is-Tablet-Viewer': 'false', 'CloudFront-Viewer-Country': 'UA', 'Content-Type': 'application/json', 'Host': 'HOST.execute-api.us-east-1.amazonaws.com', 'Postman-Token': 'b63589cf-40dc-43bb-bc16-37a4044170ef', 'User-Agent': 'PostmanRuntime/7.29.0', 'Via': '1.1 HOST.cloudfront.net (CloudFront)', 'X-Amz-Cf-Id': '==', 'X-Amzn-Trace-Id': 'Root=', 'X-Forwarded-For': '91.208.153.1, 54.239.171.73', 'X-Forwarded-Port': '443', 'X-Forwarded-Proto': 'https'}, 'multiValueHeaders': {'Accept': ['*/*'], 'Accept-Encoding': ['gzip, deflate, br'], 'CloudFront-Forwarded-Proto': ['https'], 'CloudFront-Is-Desktop-Viewer': ['true'], 'CloudFront-Is-Mobile-Viewer': ['false'], 'CloudFront-Is-SmartTV-Viewer': ['false'], 'CloudFront-Is-Tablet-Viewer': ['false'], 'CloudFront-Viewer-Country': ['UA'], 'Content-Type': ['application/json'], 'Host': ['HOST.execute-api.us-east-1.amazonaws.com'], 'Postman-Token': ['b63589cf-40dc-43bb-bc16-37a4044170ef'], 'User-Agent': ['PostmanRuntime/7.29.0'], 'Via': ['1.1 13182ff42379bbc1098730eb0992dbae.cloudfront.net (CloudFront)'], 'X-Amz-Cf-Id': ['Zv9A5svGpQsMHJl9JpF7I6E6lbCmrKnhuzJJtoGjaKnpNMMk4aibvg=='], 'X-Amzn-Trace-Id': ['Root='], 'X-Forwarded-For': ['91.208.153.1, 54.239.171.73'], 'X-Forwarded-Port': ['443'], 'X-Forwarded-Proto': ['https']}, 'queryStringParameters': None, 'multiValueQueryStringParameters': None, 'pathParameters': None, 'stageVariables': None, 'requestContext': {'resourceId': 'q5leiw', 'resourcePath': '/dragons', 'httpMethod': 'POST', 'extendedRequestId': 'M9nWSGX0IAMFW3g=', 'requestTime': '03/Feb/2022:11:13:56 +0000', 'path': '/Prod/dragons', 'accountId': '939694363734', 'protocol': 'HTTP/1.1', 'stage': 'Prod', 'domainPrefix': 'HOST', 'requestTimeEpoch': , 'requestId': '', 'identity': {'cognitoIdentityPoolId': None, 'accountId': None, 'cognitoIdentityId': None, 'caller': None, 'sourceIp': '91.208.153.1', 'principalOrgId': None, 'accessKey': None, 'cognitoAuthenticationType': None, 'cognitoAuthenticationProvider': None, 'userArn': None, 'userAgent': 'PostmanRuntime/7.29.0', 'user': None},  'body': '{\r\n    "name": "dragon",\r\n    "breed": "dragon",\r\n    "danger_rating": 6,\r\n    "description": "description"\r\n}', 'isBase64Encoded': False}

更新：我发现了新的有趣的东西 - API 网关中我的请求正文的类型 - 字符串。为什么这样？如果我测试 Lambda - 一切正常，但是 API Gateway 确实...

Answer 1

根据您共享的日志，名称键不直接在事件对象下。您必须通过以下方式获得价值：

table.put_item(
        Item={
            'name': event['body']['name']
            .
            .
        }
    )

Answer 2

正如我之前注意到的那样 API 网关将请求主体作为字符串，而不是 JSON。

我刚刚添加了 json.loads(event['body'])。就这样:)

不管怎么说，这听起来像是一个丑陋的骇客。如果您知道更好的解决方案，请写信给我。

谢谢大家 ;)

您也可以在这里找到更好的解释：

Lambda execution failed with status 200 due to customer function error: 'name'

Lambda execution failed with status 200 due to customer function error: 'name'

python

amazon-web-services

aws-lambda

aws-api-gateway