Singed S3 Lambda

index.js

'use strict';

console.log('Loading function');

const aws = require('aws-sdk');
const s3 = new aws.S3({signatureVersion: 'v4'});

exports.handler = (event, context, callback) => {
    
    const bucket = process.env.S3_BUCKET_NAME;

    const requestBody = JSON.parse(event.body);
    
    console.log(requestBody);
    
    const key = requestBody["object_key"];
    
    console.log(key);
    
    const params = {Bucket: bucket, Key: key, Expires: 10};
    
    s3.getSignedUrl('putObject', params, (error, url) => {
        if (error) {
            callback(error);
        }else{
            var responseBody = {
                "URL": url
            };
            var response = {
                "statusCode": 200,
                "body": JSON.stringify(responseBody)
            };
            callback(null, response);
        }
    });
};