Uploading multiple files to AWS S3 using NodeJS

I'm trying to upload all files within my directory to my S3 instance using NodeJS. I'm able to upload one file at a time if I explicitly give the file path + literal string for the Key: field.

Below is the script I'm using:

var AWS = require('aws-sdk'),
    fs = require('fs');

// For dev purposes only
AWS.config.update({ accessKeyId: '...', secretAccessKey: '...' });

// reg ex to match
var re = /\.txt$/;

// ensure that this file is in the directory of the files you want to run the cronjob on
fs.readdir(".", function(err, files) {
    if (err) {
    console.log( "Could not list the directory.", err)
    process.exit( 1 )
    }


    var matches = files.filter( function(text) { return re.test(text) } )
    // make one pass and print the files in the directoery
    // var matchedfiles = re.exec(files)
    numFiles = matches.length


    if ( numFiles ) {
        // Read in the file, convert it to base64, store to S3

        for( i = 0; i < numFiles; i++ ) {
            fs.readFile(matches[i], function (err, data) {
                if (err) { throw err; }

                // Buffer Pattern; how to handle buffers; straw, intake/outtake analogy
                var base64data = new Buffer(data, 'binary')


                var s3 = new AWS.S3()
                    s3.putObject({
                       Bucket: 'noonebetterhaventakenthisbucketnname',
                        Key: matches[i],
                        Body: base64data,
                        ACL: 'public-read'
                     }, function (resp) {
                        console.log(arguments);
                        console.log('Successfully uploaded package.')
                    })
            })
        }
    }
})

It produces this error for each file attempted to upload to S3:

{ '0': 
   { MissingRequiredParameter: Missing required key 'Key' in params
       at ParamValidator.fail (/Users/stevenle/Documents/aws-nodejs/node_modules/aws-sdk/lib/param_validator.js:50:37)
       at ParamValidator.validateStructure (/Users/stevenle/Documents/aws-nodejs/node_modules/aws-sdk/lib/param_validator.js:61:14)
       at ParamValidator.validateMember (/Users/stevenle/Documents/aws-nodejs/node_modules/aws-sdk/lib/param_validator.js:88:21)
       at ParamValidator.validate (/Users/stevenle/Documents/aws-nodejs/node_modules/aws-sdk/lib/param_validator.js:34:10)
       at Request.VALIDATE_PARAMETERS (/Users/stevenle/Documents/aws-nodejs/node_modules/aws-sdk/lib/event_listeners.js:114:42)
       at Request.callListeners (/Users/stevenle/Documents/aws-nodejs/node_modules/aws-sdk/lib/sequential_executor.js:105:20)
       at callNextListener (/Users/stevenle/Documents/aws-nodejs/node_modules/aws-sdk/lib/sequential_executor.js:95:12)
       at /Users/stevenle/Documents/aws-nodejs/node_modules/aws-sdk/lib/event_listeners.js:74:9
       at finish (/Users/stevenle/Documents/aws-nodejs/node_modules/aws-sdk/lib/config.js:313:7)
       at /Users/stevenle/Documents/aws-nodejs/node_modules/aws-sdk/lib/config.js:331:9
     message: 'Missing required key \'Key\' in params',
     code: 'MissingRequiredParameter',
     time: 2017-04-27T15:56:41.169Z },
  '1': null }
Successfully uploaded package.

How do I get the Key value to take in an iterative variable of file names?

via Steven_