app.js

const express = require('express')
const BusBoy = require('busboy')
const path = require('path')
const os = require('os')
const fs = require('fs')

const app = express()

app.post('/', (req, res) => {
  const busboy = new BusBody({ headers: req.headers })
  busboy.on('file', (fieldname, file, filename, encoding, mimetype) => {
    const saveTo = path.join(os.tmpDir(), path.basename(fieldname))
    file.pipe(fs.createWriteStream(saveTo))
  }).on('finish', () => {
    res.json({ ok: true })
  })
})

app.listen(process.env.PORT || 8080, () => {
 console.log('server running on port 8080')
})