node.js - AWS API Gateway "Unsupported method\"未定义\""作为响应

Question

我正在设置一个 AWS Lambda 函数来连接到我的 DynamoDB。为了访问它，我还设置了一个 API 网关。

当我测试它时，lambda 似乎可以工作。因此，我认为问题出在 API 网关设置中。

对于 lambda，我配置了以下测试事件: 我配置了一个测试事件，如下所示:

{
  "httpMethod": "GET"
}

此测试事件给了我以下响应:

Response:
{
  "statusCode": "200",
  "body": "{\"Items\":[{\"id\":1,\"brand\":\"Test brand\",\"title\":\"Test product\"}],\"Count\":1,\"ScannedCount\":1}",
  "headers": {
    "Content-Type": "application/json"
  }
}

对于 API 网关，我尝试过以下测试:

我尝试在 lambda 管理控制台中自动创建 API 网关。重新创建 lambda 和 API 网关。

Lambda 函数:

console.log('Loading function');

const doc = require('dynamodb-doc');

const dynamo = new doc.DynamoDB();


/**
 * Demonstrates a simple HTTP endpoint using API Gateway. You have full
 * access to the request and response payload, including headers and
 * status code.
 *
 * To scan a DynamoDB table, make a GET request with the TableName as a
 * query string parameter. To put, update, or delete an item, make a POST,
 * PUT, or DELETE request respectively, passing in the payload to the
 * DynamoDB API as a JSON body.
 */
exports.handler = (event, context, callback) => {
    //console.log('Received event:', JSON.stringify(event, null, 2));

    const done = (err, res) => callback(null, {
        statusCode: err ? '400' : '200',
        body: err ? err.message : JSON.stringify(res),
        headers: {
            'Content-Type': 'application/json',
        },
    });

    switch (event.httpMethod) {
        case 'DELETE':
            dynamo.deleteItem(JSON.parse(event.body), done);
            break;
        case 'GET':
            dynamo.scan({ "TableName": "productdb" }, done);
            //dynamo.scan({"TableName":"productdb"})
            break;
        case 'POST':
            dynamo.putItem(JSON.parse(event.body), done);
            break;
        case 'PUT':
            dynamo.updateItem(JSON.parse(event.body), done);
            break;
        default:
            done(new Error(`Unsupported method "${event.httpMethod}"`));
    }
};

测试中的 API 网关日志:

Execution log for request 885e5505-2212-11e9-aee0-7f024016f574
Sun Jan 27 09:04:20 UTC 2019 : Starting execution for request: 885e5505-2212-11e9-aee0-7f024016f574
Sun Jan 27 09:04:20 UTC 2019 : HTTP Method: GET, Resource Path: /
Sun Jan 27 09:04:20 UTC 2019 : Method request path: {}
Sun Jan 27 09:04:20 UTC 2019 : Method request query string: {}
Sun Jan 27 09:04:20 UTC 2019 : Method request headers: {}
Sun Jan 27 09:04:20 UTC 2019 : Method request body before transformations: 
Sun Jan 27 09:04:20 UTC 2019 : Endpoint request URI: https://lambda.eu-central-1.amazonaws.com/2015-03-31/functions/arn:aws:lambda:eu-central-1:304886708348:function:dynamoDBService/invocations
Sun Jan 27 09:04:20 UTC 2019 : Endpoint request headers: {x-amzn-lambda-integration-tag=885e5505-2212-11e9-aee0-7f024016f574, Authorization=*****************************************************************************************************************************************************************************************************************************************************************************************500617, X-Amz-Date=20190127T090420Z, x-amzn-apigateway-api-id=lqhm3agxxf, X-Amz-Source-Arn=arn:aws:execute-api:eu-central-1:304886708348:lqhm3agxxf/test-invoke-stage/GET/, Accept=application/json, User-Agent=AmazonAPIGateway_lqhm3agxxf, X-Amz-Security-Token=FQoGZXIvYXdzEOH//////////wEaDFvawdYGjH/+gSI14yK9AzQFZtlDghAr2NUHIhLGWmeJkKL8sUP3L6fu0h5PtFPN7wA7hgfWMtUNHCWyGykG0g5Zs81zKx5bUGMLCMK2zuVwD4WMgBRmkx40bZYehHdeS8czOxRTbQIqwP1lfZ0d74l4MqG4g8XpigkcLACLEn6buaq37rO4WYOo+J8ecFeSpti+u+V8OON4idxxXEHiYGJEc23OwjVvf3GTr1EUscB+Lsp/nw58oCWQArUA6LLSwcnGYXYcmnPav2Xs8mJgvqnVowxxYre0N8Gca8D9XBN2Y93/qnVTsOI5nWHSUQOnwaoXSZzgBAXKrUV1S5X+UH3zQI9p [TRUNCATED]
Sun Jan 27 09:04:20 UTC 2019 : Endpoint request body after transformations: 
Sun Jan 27 09:04:20 UTC 2019 : Sending request to https://lambda.eu-central-1.amazonaws.com/2015-03-31/functions/arn:aws:lambda:eu-central-1:304886708348:function:dynamoDBService/invocations
Sun Jan 27 09:04:20 UTC 2019 : Received response. Integration latency: 17 ms
Sun Jan 27 09:04:20 UTC 2019 : Endpoint response body before transformations: {"statusCode":"400","body":"Unsupported method \"undefined\"","headers":{"Content-Type":"application/json"}}
Sun Jan 27 09:04:20 UTC 2019 : Endpoint response headers: {Date=Sun, 27 Jan 2019 09:04:20 GMT, Content-Type=application/json, Content-Length=108, Connection=keep-alive, x-amzn-RequestId=6c00229e-caa1-4d37-aeaa-7c1cbd0ddd71, x-amzn-Remapped-Content-Length=0, X-Amz-Executed-Version=$LATEST, X-Amzn-Trace-Id=root=1-5c4d7414-e52b0fba267596b50fdbb102;sampled=0}
Sun Jan 27 09:04:20 UTC 2019 : Method response body after transformations: {"statusCode":"400","body":"Unsupported method \"undefined\"","headers":{"Content-Type":"application/json"}}
Sun Jan 27 09:04:20 UTC 2019 : Method response headers: {X-Amzn-Trace-Id=Root=1-5c4d7414-e52b0fba267596b50fdbb102;Sampled=0, Access-Control-Allow-Origin=*, Content-Type=application/json}
Sun Jan 27 09:04:20 UTC 2019 : Successfully completed execution
Sun Jan 27 09:04:20 UTC 2019 : Method completed with status: 200

我希望结果与 lambda 返回的测试事件相同。

Answer 1

当您创建 API 方法时，您需要选择“使用 Lambda 代理集成”选项，以便可以在Lambda 函数中的 event 对象。

来自docs :

You can set up a Lambda proxy integration for any API method. But a Lambda proxy integration is more potent when it is configured for an API method involving a generic proxy resource. The generic proxy resource can be denoted by a special templated path variable of {proxy+}, the catch-all ANY method placeholder, or both. The client can pass the input to the backend Lambda function in the incoming request as request parameters or applicable payload. The request parameters include headers, URL path variables, query string parameters, and the applicable payload. The integrated Lambda function verifies all of the input sources before processing the request and responding to the client with meaningful error messages if any of the required input is missing.

您可以在 API Gateway 实例的“创建方法”屏幕上找到“使用 Lambda 代理集成”选项:

编辑:作为引用，您可以看出 API Gateway 方法未使用 Lambda 代理集成，因为在“集成请求”下，类型为“LAMBDA”，但在使用 Lambda 代理集成时类型是“LAMBDA_PROXY”。