unable to proxy a PDF file in node.js

Question

I need to download a pdf from an endpoint I receive from an external service, store the pdf in my database and send it back to the browser (or whoever is calling the API on my system). For some reasons I can't understand if I put the service's URL directly on the browser it opens the pdf correctly, but if I run this code

var express = require('express');
var request = require('request');

var app = express();
var _PORT = 9008;

console.log("starting server on port " + _PORT);

// will return an unordered list of all items.
app.get('/', function(req, res) {
    console.log("Proxying stuff");

    var get_options = {
        'rejectUnauthorized': false,
        'url': 'http://www.urartuuniversity.com/content_images/pdf-sample.pdf',
        'method': 'GET'
    };

    request(get_options, function(err, get_resp, body){
        if(err){
            console.log(err.message);
            res.json({error: err})
        }

        console.log('data received from service:' + body.length);

        res.type('application/pdf');
        res.end(body);
    });
});

app.listen(_PORT);

by calling localhost:9008/ from the browser I only get 2 blank pages. I kind of tried them all changing all possible configurations and encodings but so far I only got blank pages.

In case you need more informations please ask.

Answer 1

Pleae change

var get_options = {
        'rejectUnauthorized': false,
        'url': 'http://www.urartuuniversity.com/content_images/pdf-sample.pdf',
        'method': 'GET'
    };

    request(get_options, function(err, get_resp, body){
        if(err){
            console.log(err.message);
            res.json({error: err})
        }

        console.log('data received from service:' + body.length);

        res.type('application/pdf');
        res.end(body);
    });

to

request
  .get('http://www.urartuuniversity.com/content_images/pdf-sample.pdf')
  .on('response', function(response) {
    console.log(response.statusCode) 
    console.log(response.headers['content-type'])
  })
  .on('end', function(){
     // store pdf into DB here.
     fs.createReadStream('pdf-sample.pdf').pipe(res); // send the pdf to client
  })
  .pipe(fs.createWriteStream('pdf-sample.pdf')) //store the pdf in your server

Answer 2

So, I finally found how to do it:

request
    .get('http://www.urartuuniversity.com/content_images/pdf-sample.pdf')
    .on('response', function(response) {

        var chunks = [];
        response.on('data', function(chunk){
            chunks.push(chunk);
        });

        response.on('end', function(){
            var finalData = new Buffer.concat(chunks);
            myDatabase.store(finalData);

            res.type('application/pdf');
            res.end(finalData, 'binary');
        });

Answer 3

This could be super easy as

app.use('/pdf', (req, res) => {
  let url = 'http://www.urartuuniversity.com/content_images/pdf-sample.pdf';
  let src = request(url);
  req.pipe(src).pipe(res);
});

You don't have to store data on the server this way.