AWS Lambda 与 API 网关和 Node.js 返回 HTTP 50

Question

我正在测试 AWS Lambda 和 API 网关之间的功能。 我的 lambda function 正在使用节点，我已经定义了我想从 S3 中提取的参数。 这是我的 lambda：

console.log('Loading function');
const aws = require('aws-sdk');
const s3 = new aws.S3({ apiVersion: '2006-03-01' });

exports.handler = async (event, context) => {
    const bucket = event.Records[0].s3.bucket.name;
    const key = decodeURIComponent(event.Records[0].s3.object.key.replace(/\+/g, ' '));
    const params = {
        Bucket: 'testing-api-lambda-s3-jfr',
        Key: 'sample-file-testing.csv',
    };
    
    exports.sendRes = (body, status = 200) => {
    const response = {
        statusCode: status,
        headers: {
            "Content-Type": "application/json"
        },
        body: JSON.stringify(body)
    };
    return response;
};

lambda 上的测试事件返回 OK，所以我认为 lambda 很好：

Test Event Name
test

Response
"text/csv"

Function Logs
START RequestId: 07d8ea41-976b-4e49-9fb7-ccfafca15dcf Version: $LATEST
2022-02-03T19:38:46.871Z    07d8ea41-976b-4e49-9fb7-ccfafca15dcf    INFO    CONTENT TYPE: text/csv
END RequestId: 07d8ea41-976b-4e49-9fb7-ccfafca15dcf
REPORT RequestId: 07d8ea41-976b-4e49-9fb7-ccfafca15dcf  Duration: 499.10 ms Billed Duration: 500 ms Memory Size: 128 MB Max Memory Used: 80 MB

Request ID
07d8ea41-976b-4e49-9fb7-ccfafca15dcf

在我的 API 网关上，我将其配置为 GET，没有定义查询字符串或路径参数：

在测试中，错误是：

{
  "message": "Internal server error"
}

完整的 API 网关执行日志：

Execution log for request 2866b8b2-bd57-49f7-aad9-1a9279612364
Thu Feb 03 19:44:42 UTC 2022 : Starting execution for request: 2866b8b2-bd57-49f7-aad9-1a9279612364
Thu Feb 03 19:44:42 UTC 2022 : HTTP Method: GET, Resource Path: /
Thu Feb 03 19:44:42 UTC 2022 : Method request path: {}
Thu Feb 03 19:44:42 UTC 2022 : Method request query string: {}
Thu Feb 03 19:44:42 UTC 2022 : Method request headers: {}
Thu Feb 03 19:44:42 UTC 2022 : Method request body before transformations: 
Thu Feb 03 19:44:42 UTC 2022 : Endpoint request URI: https://lambda.us-east-1.amazonaws.com/2015-03-31/functions/arn:aws:lambda:us-east-1:143578772304:function:getObjectNode/invocations
Thu Feb 03 19:44:42 UTC 2022 : Endpoint request headers: {X-Amz-Date=20220203T194442Z, x-amzn-apigateway-api-id=vzcwgufch1, Accept=application/json, User-Agent=AmazonAPIGateway_vzcwgufch1, Host=lambda.us-east-1.amazonaws.com, X-Amz-Content-Sha256=ec78e1a3cab036558869aced97bcd18b2213fcab99c7a38ddc15d6bf509a5f5b, X-Amzn-Trace-Id=Root=1-61fc30aa-f6d4b97e6327eed29d022b45, x-amzn-lambda-integration-tag=2866b8b2-bd57-49f7-aad9-1a9279612364, Authorization=*********************************************************************************************************************************************************************************************************************************************************************************************************************************************a0c1a3, X-Amz-Source-Arn=arn:aws:execute-api:us-east-1:143578772304:vzcwgufch1/test-invoke-stage/GET/, X-Amz-Security-Token=IQoJb3JpZ2luX2VjEEQaCXVzLWVhc3QtMSJIMEYCIQDE4SYIymD/u99+1dzLRSk8U+DbUxCC9ygNy6aYr1SjhQIhAN9P2Oh/UyQl1L0mLSNTGhNRFGz2G5irLwGI7gHbs/4eKvoDCHwQABoMM [TRUNCATED]
Thu Feb 03 19:44:42 UTC 2022 : Endpoint request body after transformations: {"resource":"/","path":"/","httpMethod":"GET","headers":null,"multiValueHeaders":null,"queryStringParameters":null,"multiValueQueryStringParameters":null,"pathParameters":null,"stageVariables":null,"requestContext":{"resourceId":"dw7k4w6igh","resourcePath":"/","httpMethod":"GET","extendedRequestId":"M-yKsEC5IAMFegA=","requestTime":"03/Feb/2022:19:44:42 +0000","path":"/","accountId":"143578772304","protocol":"HTTP/1.1","stage":"test-invoke-stage","domainPrefix":"testPrefix","requestTimeEpoch":1643917482625,"requestId":"2866b8b2-bd57-49f7-aad9-1a9279612364","identity":{"cognitoIdentityPoolId":null,"cognitoIdentityId":null,"apiKey":"test-invoke-api-key","principalOrgId":null,"cognitoAuthenticationType":null,"userArn":"arn:aws:iam::143578772304:user/fernando","apiKeyId":"test-invoke-api-key-id","userAgent":"aws-internal/3 aws-sdk-java/1.12.138 Linux/5.4.156-94.273.amzn2int.x86_64 OpenJDK_64-Bit_Server_VM/25.312-b07 java/1.8.0_312 vendor/Oracle_Corporation cfg/retry-mod [TRUNCATED]
Thu Feb 03 19:44:42 UTC 2022 : Sending request to https://lambda.us-east-1.amazonaws.com/2015-03-31/functions/arn:aws:lambda:us-east-1:143578772304:function:getObjectNode/invocations
Thu Feb 03 19:44:42 UTC 2022 : Received response. Status: 200, Integration latency: 24 ms
Thu Feb 03 19:44:42 UTC 2022 : Endpoint response headers: {Date=Thu, 03 Feb 2022 19:44:42 GMT, Content-Type=application/json, Content-Length=261, Connection=keep-alive, x-amzn-RequestId=62424064-5199-48b7-ad4e-f8976d86e514, X-Amz-Function-Error=Unhandled, x-amzn-Remapped-Content-Length=0, X-Amz-Executed-Version=$LATEST, X-Amzn-Trace-Id=root=1-61fc30aa-f6d4b97e6327eed29d022b45;sampled=0}
Thu Feb 03 19:44:42 UTC 2022 : Endpoint response body before transformations: {"errorType":"TypeError","errorMessage":"Cannot read property '0' of undefined","trace":["TypeError: Cannot read property '0' of undefined","    at Runtime.exports.handler (/var/task/index.js:12:33)","    at Runtime.handleOnce (/var/runtime/Runtime.js:66:25)"]}
Thu Feb 03 19:44:42 UTC 2022 : Lambda execution failed with status 200 due to customer function error: Cannot read property '0' of undefined. Lambda request id: 62424064-5199-48b7-ad4e-f8976d86e514
Thu Feb 03 19:44:42 UTC 2022 : Method completed with status: 502

有什么建议么？ 谢谢你

Answer 1

执行日志中的错误消息表明event object 没有包含一些存储桶信息的数组Records 。 原因是API网关请求事件没有这个数组。 只要您不在 REST 请求正文中传递存储桶信息，API 网关就不会与您的存储桶有关。

此外，您期望使用以下行从 API 网关请求中获得存储桶名称和密钥：

const bucket = event.Records[0].s3.bucket.name;
const key = decodeURIComponent(event.Records[0].s3.object.key.replace(/\+/g, ' '));

但是你从来没有在任何地方真正使用过这些变量，本质上是用这些行硬编码你自己的存储桶名称和密钥：

const params = {
    Bucket: 'testing-api-lambda-s3-jfr',
    Key: 'sample-file-testing.csv',
};

如果不需要，只需从代码中删除这两行即可。

const bucket = event.Records[0].s3.bucket.name;
const key = decodeURIComponent(event.Records[0].s3.object.key.replace(/\+/g, ' '));

I feel like you are confusing how the event object should look like when your Lambda is triggered by an S3 event, compared to what it would look like if the Lambda would be triggered by API Gateway proxy integration. 如果您想知道当 API 网关调用event object 时它是如何构造的，您可能需要查看 AWS 文档中的此页面。

Answer 2

根据执行日志，您的 API 网关无法转换从 lambda 收到的响应。

您需要为您的 API 提供一个 model 定义响应结构，以便它可以转换响应。 这属于映射模板。

https://docs.aws.amazon.com/apigateway/latest/developerguide/set-up-gateway-response-using-the-console.html