var bucketReader = require('bucket-reader');

var bucketName = .... // S3 Bucket name
var keyName = .... // file name with relative path

bucketReader.BucketData(bucketName, keyName, function(err, data) { 
  if (err) {
        console.log(err, err.stack);
    } else {
        console.log(data);
    }
  });