Upload to s3 from node.js

import aws          from 'aws-sdk-promise';
import url          from 'url';
import https        from 'https';
import fs           from 'mz/fs';
import _            from 'lodash';
import path         from 'path';
import crypto       from 'crypto';

(async function() {

// Compute hash
var filename = path.join(__dirname, 'test.tar.gz');
var hash = await new Promise((accept, reject) => {
  var md5 = crypto.createHash('md5');
  var stream = fs.createReadStream(filename);
  stream.on('data', d => md5.update(d));
  stream.on('end', () => accept(md5.digest('base64')));
  stream.on('error', reject);
});
console.log("hash: " + hash);

// Generated signed url
var s3 = new aws.S3();
var signedURL = await new Promise((accept, reject) => {
  s3.getSignedUrl('putObject', {
    Bucket:       'test-bucket-for-any-garbage',
    Key:          'jonasfj-upload-test/test.tar',
    ContentType:  'application/x-tar',
    Expires:      15 * 60, // URL expiration
    ContentMD5:   hash,
    Metadata: {
      "content-sha256":  "Hello World2"
    }
  }, (err, url) => err ? reject(err) : accept(url));
});

console.log("Signed URL: "  + signedURL);

// Open file
var stat      = await fs.stat(filename);
var stream    = fs.createReadStream(filename);

// Upload
var urlOpts = url.parse(signedURL);

var req = https.request({
  method:     'PUT',
  host:       urlOpts.host,
  path:       urlOpts.path,
  headers: {
    'content-type':     'application/x-tar',
    'content-length':   stat.size,
    'content-encoding': 'gzip',
    'cache-control':    'public, no-transform',
    'content-md5':      hash
  }
});

// Pipe stream
stream.pipe(req);

var res = await new Promise((accept, reject) => {
  req.on('response', accept);
  req.on('error', reject);
  req.setTimeout(5 * 60 * 1000, reject);
});

// Print status code
console.log("Response Code: " + res.statusCode);

// Discard response text
res.resume();


})().catch(err => console.log(err.stack));