Node JS upload binary file to another server

Question

I've got an audio file which I post to a server for translation. I've managed to create a request in postman, but I do not know how to write the file to this server. Below is the code I have got so far:

var http = require("https");

var options = {}

var req = http.request(options, function (res) {
  var chunks = [];

  res.on("data", function (chunk) {
    chunks.push(chunk);
  });

  res.on("end", function () {
    var body = Buffer.concat(chunks);
    console.log(body.toString());
   });
});

options{} is filled with method/hostname/port ofcourse. In postman I add "binary" file, but I cannot figger out how to write a file to the request in Node JS.

Answer 1

One solution that would easily fit into your current program without too much work is to make use of the form-data module on npm.

The form-data module makes ease of multipart requests in node. The following is a simple example of how to use.

var http = require("https");
var FormData = require('form-data');
var fs = require('fs')

var form = new FormData();
form.append('my_field', fs.createReadStream('my_audio.file'));

var options = {
  host: 'your.host',
  port: 443,
  method: 'POST',
  // IMPORTANT!
  headers: form.getHeaders()
}

var req = http.request(options, function (res) {
  var chunks = [];

  res.on("data", function (chunk) {
    chunks.push(chunk);
  });

  res.on("end", function () {
    var body = Buffer.concat(chunks);
    console.log(body.toString());
   });
});

// Pipe form to request
form.pipe(req);

In a "real-world" scenario you would want to do a lot more error checking. Also, there are plenty of other http clients on npm that make this process easy as well (the request module uses form-data BTW). Check out request, and got if you are interested.

For sending a binary request the fundamentals are still the same, req is a writable stream. As such, you can pipe data into the stream, or write directly with req.write(data). Here's an example.

var http = require('https');
var fs = require('fs');

var options = {
  // ...
  headers: {
    'Content-Type': 'application/octet-stream'
  }
}

var req = http.request(options, function (res) {
  var chunks = [];

  res.on("data", function (chunk) {
    chunks.push(chunk);
  });

  res.on("end", function () {
    var body = Buffer.concat(chunks);
    console.log(body.toString());
   });
});


var audioFile = fs.createReadStream('my_audio.file', { encoding: 'binary' });
audioFile.pipe(req);

Note, that if you use the write method explicitly req.write(data) you must call req.end(). Also, the you may want to take a look at the encoding options for Node's Buffer (docs).

Answer 2

You can use the request package on npm.

Install the request module from npm: npm install request --save

Then use the request module to send your request.

Have a look at https://www.npmjs.com/package/request for details on implementation.