AWS node.js lambda请求dynamodb但无响应（无错误，无返回数据） [英] AWS node.js lambda request dynamodb but no response (no err, no return data)

问题描述

我正在使用react-native播放aws mobilehub，我希望它可以为我加快后端托管的速度。

I am playing the aws mobilehub with react-native and I was hoping that it can speed up the backend hosting for me.

但是，我无法使其后端API正常工作。经过他们的文档长期运行后，我确定了其lambda函数与dynamodb服务之间的问题。

However, I cannot get its backend API working. After a long run with their docs, I pin down the problem between its lambda function and dynamodb service.

任何想法都会受到赞赏！

Any thoughts are greatly appreciated!

正如标题所述：我的aws lambda函数可以请求其dynamodb，但没有响应。
这里出了什么问题？
或如何从AWS dynamodb获取调试信息？ （我已启用并启用了Cloudtrial，但它似乎也没有dynamodb的操作日志。）

As the titled says: my aws lambda functions can request its dynamodb but has no response. What went wrong here? Or how can I get debug info from AWS dynamodb? (I gg and enabled Cloudtrial but it doesn't seem to have operation logs of the dynamodb too.)

这里有最简单的node.js 6.10代码：

Here I have the simplest node.js 6.10 codes:

const AWS = require('aws-sdk');
AWS.config.update({region: 'us-east-2'});
const dynamodb = new AWS.DynamoDB.DocumentClient();

exports.handler = function(event, context, callback) {
    var responseCode = 200;
    var requestBody, httpMethod, res;
    console.log("request: " + JSON.stringify(event));

    // Request Body
    requestBody = event.body;

    /*testing dynamodb with put*/

    console.log("PUT begins");
    let putItemParams2 = {
        TableName: "xxxx-mobilehub-xxxx-Test",//tableName
        Item: {businessId:'putItemParams2r3',test:'yooo', hmm:'hhhh'}
    };
    console.log("putItemParams2: ",putItemParams2);
    dynamodb.put(putItemParams2, (err, data) => {
        console.log("putItemParams2");
        if (err) console.log("dynamodb err: ",err, err.stack); // an error occurred
        else     console.log("dynamodb data: ",data);           // successful response
    });
    console.log("PUT end");

    var response = {
        statusCode: responseCode
        //....
    };

    ...
    //comment out context.succeed here to avoid program termination before intended. 
    //console.log("response: " + JSON.stringify(response))
    //context.succeed(response);
};

日志

先前的代码为从AWS CloudWatch触发后，我可以看到日志：

Logs

When the previouse codes are triggered, from AWS CloudWatch I can see logs:

START RequestId: 3d7c5f7f-1b98-11e8-ad00-93a6d10c8f4e Version: $LATEST
[timestamp] PUT begins
[timestamp] putItemParams2: { TableName: 'xxx-mobilehub-xxxx-Test',
Item: { businessId: 'putItemParams2r3', test: 'yooo', hmm: 'hhhh'}}
[timestamp] put end
END RequestId: 3d7c5f7f-1b98-11e8-ad00-93a6d10c8f4e

所以没有错误，没有数据，没有响应。我检查了我的dynamodb，没有插入任何东西。

So no err, no data, no response. I checked my dynamodb and there is nothing insert.

条件＃1：此动态表具有公共访问权限，因为我想排除身份验证问题。

condition#1: this dynamodb table has public access since I want to rule out the auth problem.

条件＃2：我确保我的lambda函数可以访问这些表。例如arn：aws：dynamodb：：xxxx：table / xxxx-mobilehub-xxxx-允许一切

condition#2: I ensure that my lambda function has access to these tables. e.g. arn:aws:dynamodb::xxxx:table/xxxx-mobilehub-xxxx- allow everything

条件＃3：我为自己构建了一个简单的node.js执行（aws-sdk），并且该服务器使用相同的代码即可正常工作。
我能够获取&放入项目int&

condition#3: I build myself a simple node.js to execute the (aws-sdk)and this server works perfectly fine with the same code.. I am able to "get" &"put" items int & out from my dynamodb table.

我的本​​机代码使用'aws-amplify-反应本地。哪个API.put很好并且lambda函数至少正在接收api调用（来自问题＃1）。

my react-native code use 'aws-amplify-react-native'. Which the API.put is fine and the lambda function is at least receiving the api call (from problem#1).

但是，API.get返回403错误，并且lambda函数甚至没有此操作的日志。

However, API.get returns me 403 error, and the lambda function doesn't even has log for this operation..

async function getBusiness(){
    const path = "/Test";
    const api = "TestCRUD";
    let queryGetBusiness = {body: {userId: "hmmm"}};

    try {
        let apiResponse = await API.get(api, path, queryGetBusiness)//.then((data)=>{console.log(data)});
        let apiResponseJson = await JSON.stringify(apiResponse);
        console.log("response from saving Business: " + apiResponseJson);
    }
    catch (e) {console.log(e);}
} 

PS（AWS可以用此mobilehub做得更好。他们的文档缺少详细信息，而我猜awsmobile cloud-api调用存在一些问题。）

P.S.(AWS could do much better with this mobilehub.. their documentation is lacking details and awsmobile cloud-api invoke has some problems I guess.)

推荐答案

const AWS = require('aws-sdk');
AWS.config.update({ region: 'us-east-2' });
const dynamodb = new AWS.DynamoDB.DocumentClient();

exports.handler = function (event, context, callback) {
    var responseCode = 200;
    var requestBody, httpMethod, res;
    console.log("request: " + JSON.stringify(event));

    // Request Body
    requestBody = event.body;

    /*testing dynamodb with put*/
    console.log("PUT begins");
    let putItemParams2 = {
        TableName: "xxxx-mobilehub-xxxx-Test",//tableName
        Item: { businessId: 'putItemParams2r3', test: 'yooo', hmm: 'hhhh' }
    };
    console.log("putItemParams2: ", putItemParams2);
    dynamodb.put(putItemParams2, (err, data) => {
        console.log("putItemParams2");
        if (err) console.log("dynamodb err: ", err, err.stack); // an error occurred
        else {
            console.log("dynamodb data: ", data);
            context.succeed(response);
        }
        // Call these here
        console.log("PUT end");
    });

    //console.log("response: " + JSON.stringify(response))
};

确保在内部调用 context.succeed 回调函数。像上面一样。

Make sure you call context.succeed inside the callback function. Like above.

您也可以只使用 handler 函数的第三个参数-回调而不是 context.succeed 像 callback（null，response）;

You can also just use the third argument to handler function - callback instead of context.succeed like callback(null, response);

这篇关于AWS node.js lambda请求dynamodb但无响应（无错误，无返回数据）的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！