Lambda function unable to get data from dynamo DB for amazon lex - Null response

Question

I am pretty new to node and facing a problem while trying to do a simple test on AWS lambda-dynamo DB integration in order to get a response for Amazon Lex request. If someone can say what needs to be changed that would be much appreciated. thanks..

Runtime - Node js 10.x and also tried on node js 8.10.. Below is the node JS sample code :

const AWS = require('aws-sdk');

var DBHandler = require("./DBHandler")

exports.handler = async (event) => {

    console.log('This event is' +JSON.stringify(event))

    var intent = event.currentIntent.name;

    DBHandler.getalldetails(intent , function (err , data ) {
        if (err) {
            context.fail(err);
        } else {
            var response = {
            "dialogAction": {
            "type": "Close",
            "fulfillmentState": "Fulfilled",
            "message": {
                "contentType": "PlainText",
                "content": "data.Item.Message."
            } 
          }
        }

    return response
    //callback ( null, response );
        }
    });
};

Below is the ./DBHandler in another file under the same lamdba function folder.

const AWS = require('aws-sdk');

AWS.config.update({
    region:"eu-west"
});

var docClient = new AWS.DynamoDB.DocumentClient();

var tableName = "testholly";
//exports.handler = (event,context,callback) => {

var getalldetails = (Intent,callback) => {

    var params = {
        TableName : tableName,
        Key: {
            "Intent":Intent
        }
    };
    docClient.get(params,function (err,data) {
        callback (err , data);
    });
};module.exports = {
    getalldetails
};

Siva Sumanth · Accepted Answer · 2019-11-19 06:25:51Z

1

First check the Dynamo DB access permissions to that lambada. If at all not given, create a role to access the dynamoDB table and assign it to the lambda function.

If you want to access the dynamodb without role then use cognito pool ID or AWS access key Secret access key in AWS.config();

Sample:

AWS.config.update({
  accessKeyId: "",
  secretAccessKey: "",
  region: "us-east-1"
});

OR

 AWS.config.update({ 
          "region":"us-east-1"
    });
 AWS.config.credentials = new AWS.CognitoIdentityCredentials({ 
      IdentityPoolId:"Your identity_pool_id"
   });

answered Nov 19, 2019 at 6:25

Siva Sumanth

6624 silver badges11 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

LostJon · Accepted Answer · 2019-10-24 20:06:09Z

0

your response is not within your callback from getAllDetails()....it should be. So something like:

exports.handler = async (event, context, callback) => {

    console.log('This event is' + JSON.stringify(event))

    var intent = event.currentIntent.name;

    DBHandler.getalldetails(intent, function (err, data) {
        if (err) {
            context.fail(err);
        } else {
            var response = {
                "dialogAction": {
                    "type": "Close",
                    "fulfillmentState": "Fulfilled",
                    "message": {
                        "contentType": "PlainText",
                        "content": data.Item.Message
                    }
                }
            }
            callback(null, response)
        }
    });
};

You cannot use await w/ callbacks, you would need to "promisify" that bad boy. In the above, I pass the callback to the handler.

edited Oct 24, 2019 at 20:06

answered Oct 24, 2019 at 14:55

LostJon

2,39713 silver badges21 bronze badges

3 Comments

Gaurav Kulkarni Over a year ago

Hi LostJon - i get a syntax error if i move callback to pass to the handler. Parsing error - unexpected token callback

Gaurav Kulkarni Over a year ago

Thanks again LostJon - i had tried that option already, no errors but null value from Dynamo DB...

LostJon Over a year ago

can you confirm that your accessing code actually retrieves data? if not, that can be your issue

Collectives™ on Stack Overflow

Lambda function unable to get data from dynamo DB for amazon lex - Null response

2 Answers 2

Comments

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related