How to parse stream from multipart data in koa2

Question

so I'm uploading stream data inside multipart form-data

var Koa = require('koa');
var Router = require('koa-router');
const HttpStatus = require('http-status');
const fs = require('fs');
const koaBody = require('koa-body');
const request = require('request');

var FormData = require('form-data');

var formData = {
  my_field: 'my_value',
  my_file: fs.createReadStream('robot.jpg'),
};

request.post({url:'http://localhost:3456/fileStorage', formData: formData}, function(err, httpResponse, body) {
  if (err) {
    return console.error('upload failed:', err);
  }
  console.log('Upload successful!  Server responded with:', body);
});

In the server side I tried koa-multer, get errors when trying to access the file. Just use the plain koa-body, I can see the file is uploaded, but cannot save it back to a file, any hints pls ?

{ my_file: 
   File {
     domain: null,
     _events: {},
     _eventsCount: 0,
     _maxListeners: undefined,
     size: 15562,
     path: '/var/folders/l6/lmwkwk196_qfxxngv5ys0lp00000gn/T/upload_fc48a19e6ee5abf8a9a361d784725b78',
     name: 'robot.jpg',
     type: 'image/jpeg',
     ...
}

The source is this

var Koa = require('koa');
var Router = require('koa-router');
const HttpStatus = require('http-status');
const fs = require('fs');
const koaBody = require('koa-body');
//const multiparty = require('multiparty');
//const multer = require('koa-multer');
var app = new Koa();
var router = new Router();
//const upload=multer({desk: './uploads/' });

router
    .post(`/upload`, koaBody({multipart:true}),
    (ctx) => {
        console.log('----- hello ----');
        console.log(ctx.request.body.files);
        console.error('---------------');
        const writeStream = fs.createWriteStream('./111.jpg');
        ctx.request.body.files.my_file.pipe(writeStream);
    });
app.use(router.routes());
app.use(router.allowedMethods());

app.listen(3456);

Answer 1

ok, I just did this const readStream = fs.createReadStream(ctx.request.body.files.my_file.path);

so I can receive the file stream in the multipart from the http post.