How to proxy multiple file upload using NodeJs?

So, i did not found execaly how to proxy request itself, as it would do nginx, but at least i figured out how to redirect request with all it's data to different source.

So, here we use express-fileupload to get our file data from req, and form-data to create a form and send data.

import app from '@app';
import { authMw as checkJwtAndAddToRequest } from '@middleware/Auth';
import { Router } from 'express';

import fileupload, { UploadedFile } from "express-fileupload";

import FormData from 'form-data';

//add this MW to add files to you'r req

app.use(checkJwtAndAddToRequest)
app.use(fileupload());

app.post('/upload', (req, res) => {
    const uploadableFiles: UploadedFile[] | UploadedFile | undefined = req.files?.formFieldName;

    if(!uploadableFiles) {
        throw Error('Pls add files to upload them');
    }

    //Transorm single file to same form as an array of files
    const files: UploadedFile[] = Array.isArray(uploadableFiles) ? uploadableFiles : Array<UploadedFile>(uploadableFiles);

    //create form
    const form = new FormData();

    //add files
    files.forEach(
        file => form.append('files[]', file.data.toString(), file.name)
    )

    //Submit 
    form.submit({
        protocol: 'http:',
        host: process.env.API_URL,
        path: '/api-path-for/file/upload',
        method: 'POST',
        headers: {
            //Add auth token if needed
            authorization: `Bearer ${String(req.body.jwtToken)}`
        }
    }, (err, response) => {
        if(err) {
            //handle error 
            res.status(503).send('File server is currently unavailable');
        }
        //return remote response to original client
        response.pipe(res)
    });
});