Utility Function to Download Files from S3

s3-util.js

/*global module, require, Promise, console */

const aws = require("aws-sdk");
const fs = require("fs");
const s3 = new aws.S3();

const downloadFileFromS3 = function (bucket, fileKey, filePath) {
  "use strict";
  console.log("Downloading", bucket, fileKey, filePath);
  return new Promise(function (resolve, reject) {
    const file = fs.createWriteStream(filePath),
      stream = s3
        .getObject({
          Bucket: bucket,
          Key: fileKey,
        })
        .createReadStream();
    stream.on("error", reject);
    file.on("error", reject);
    file.on("finish", function () {
      console.log("downloaded", bucket, fileKey);
      resolve(filePath);
    });
    stream.pipe(file);
  });
};

module.exports = {
  downloadFileFromS3: downloadFileFromS3,
};