格式错误的Lambda代理响应:通过无服务器部署python端点

时间:2017-10-05 04:31:56

标签: python amazon-web-services aws-lambda aws-api-gateway serverless

我正在尝试通过Lambda函数(通过无服务器构建)发回JSON响应,但它出错了。

我正在创建回复:

response = {}
response["file_name"] = file_name
response["status"] = status
response["description"] = message
response["data"] = data 
return {
    "isBase64Encoded": False,
    "statusCode": 200,
    "headers": {
        "Content-Type": "application/json",
    },
    "body": json.dumps(response)
}

但AWS只返回:

{
    "message": "Internal server error"
}

我正在打印出该响应对象,它是:

{'isBase64Encoded': False, 'statusCode': 200, 'headers': {'Access-Control-Allow-Origin': '*', 'Content-Type': 'application/json'}, 'body': '{"file_name": "upload-4660557513950187006.csv", "status": "success", "description": "Success.", "data": ""}'}

当我通过API网关调用时,这是我得到的日志:

Thu Oct 05 16:21:15 UTC 2017 : Endpoint request body after transformations: {"resource":"/parse","path":"/parse","httpMethod":"POST","headers":null,"queryStringParameters":null,"pathParameters":null,"stageVariables":null,"requestContext":{"path":"/parse","accountId":"317910044022","resourceId":"xik9xe","stage":"test-invoke-stage","requestId":"test-invoke-request","identity":{"cognitoIdentityPoolId":null,"accountId":"317910044022","cognitoIdentityId":null,"caller":"AIDAJGNM4CLIWDKHDDV2U","apiKey":"test-invoke-api-key","sourceIp":"test-invoke-source-ip","accessKey":"ASIAJHGYEQDHKLLRWL6A","cognitoAuthenticationType":null,"cognitoAuthenticationProvider":null,"userArn":"arn:aws:iam::317910044022:user/chase","userAgent":"Apache-HttpClient/4.5.x (Java/1.8.0_131)","user":"AIDAJGNM4CLIWDKHDDV2U"},"resourcePath":"/parse","httpMethod":"POST","apiId":"3gvwsa0cj2"},"body":"{\n\t\"file_name\": \"upload-4660557513950187006.csv\",\n\t\"vendor\": \"\"\n}","isBase64Encoded":false}
Thu Oct 05 16:21:15 UTC 2017 : Sending request to https://lambda.us-east-1.amazonaws.com/2015-03-31/functions/arn:aws:lambda:us-east-1:317910044022:function:PyParsingService-dev-parse/invocations
Thu Oct 05 16:21:16 UTC 2017 : Received response. Integration latency: 416 ms
Thu Oct 05 16:21:16 UTC 2017 : Endpoint response body before transformations: "{\"isBase64Encoded\": false, \"statusCode\": 200, \"headers\": {\"Access-Control-Allow-Origin\": \"*\", \"Content-Type\": \"application/json\"}, \"body\": \"{\\\"file_name\\\": \\\"upload-4660557513950187006.csv\\\", \\\"status\\\": \\\"success\\\", \\\"description\\\": \\\"Success.\\\", \\\"data\\\": \\\"\\\"}\"}"
Thu Oct 05 16:21:16 UTC 2017 : Endpoint response headers: {x-amzn-Remapped-Content-Length=0, x-amzn-RequestId=36059915-a9e9-11e7-8444-438990db7407, Connection=keep-alive, Content-Length=317, Date=Thu, 05 Oct 2017 16:21:15 GMT, X-Amzn-Trace-Id=root=1-59d65bfb-7000702549081b6682b894a9;sampled=0, Content-Type=application/json}
Thu Oct 05 16:21:16 UTC 2017 : Execution failed due to configuration error: Malformed Lambda proxy response
Thu Oct 05 16:21:16 UTC 2017 : Method completed with status: 502

对Python不太熟悉 - 任何帮助将不胜感激。根据{{​​3}},需要针对API网关正确格式化响应。不确定为什么我的回复不符合API Gateway正在寻找的内容。

1 个答案:

答案 0 :(得分:1)

我弄清楚我做错了什么。由于配置错误,执行失败:格式错误的Lambda代理响应错误引用了Lambda尝试通过API网关发回的响应。无服务器自动使用Lambda代理集成。当我查看响应时,我注意到在基本响应级别(例如,"{\"isBase64Encoded\": false, \"statusCode\": 200, ...})进行了额外的转义,我认为这会触发错误。果然,当我深入挖掘时,我意识到在创建响应之后我正在转储JSON(json.dumps()),这就是抛出错误。

感谢您的回复。我无意识的错误。