Pipe uploads to S3 with node.js and express

pipe_to_s3.js

var express = require('express')
  , knox = require('knox')

var bucket = 'your-bucket'
  , s3 = knox.createClient({
      secure: true,
      bucket: bucket,
      key: your_key,
      secret: your_secret
    })
  , app = express();

app.use(express.multipart({ defer: true }));

app.post('/upload', function (req, res) {
  var headers = {
    'x-amz-acl': 'public-read'
  }

  req.form.on('part', function (part) {
    headers['Content-Length'] = part.byteCount;
    s3.putStream(part, part.filename, headers, function (err, s3res) {
      if (err) {
        return res.send(500, err);
      }
      res.statusCode = s3res.statusCode;
      s3res.pipe(res);
    });
  });
});

app.listen(8888)