AWS Lambda For The Impatient Part 2

In the first part of the AWS Lambda for the Impatient tutorial series we set to create our very first lambda function and call it through an open, public, unrestricted and unauthenticated endpoint.This time around we add security so that calling our lambdas will require the client to authenticate through an IAM Role and User name.

Step 1 - Create a new Lambda function and API Gateway endpoint
As happened in the first part, we create a new lambda called lambda_basic_execution_helloWorldNodeJS but with the added suffix of _auth. So that we can tell it apart, call it lambda_basic_execution_helloWorldNodeJS_auth.
Despite the name change, the function's code remains the same as last time:

use strict';
exports.handler = (event, context, callback) => {
 console.log('Received event:',
                 JSON.stringify(event, null, 2));
 var inputObj = JSON.parse(event["body"]);
 callback(null, {
    "statusCode": 200,
    "headers": { },
 // Echo back the first key value
    "body": JSON.stringify(
                    {"received":inputObj.key1})
 })

}

full article on i-programmer