Send file over tcp socket via proxy with streams - node.js

Question

What i tried to achieve with node.js/io.js, is to send a file from one server to another one via a proxy. To avoid memory buffering i want to use streams.
The proxy should be able to connect to multiple targets dynamically. The target connection information for the proxy should be send prior to the filedata.
With normal socket communication and buffering it is not a problem. But how or in general can this be done with streams??
var net = require('net');
var fs = require('fs');
//create readstream from file
var myFile = fs.createReadStream('E:/sample.tar.gz');
// Proxy server
//####################################################################################################
var proxy = net.createServer(function (socket) {
// Create a new connection to the TCP server
var client = net.connect('9010');
// 2-way pipe between client and TCP server
socket.pipe(client).pipe(socket);
}).listen(9000);
// Targetserver
//####################################################################################################
var server = net.createServer(function (socket) {
// create filestream to write data into file
var destfile = fs.createWriteStream('E:/sample_copy.tar.gz')
socket.on('data', function (buffer) {
console.log('Get data on targetserver...');
// write buffer to file
destfile.write(buffer);
});
socket.on('end', function () {
// release file from writestream
destfile.end();
});
}).listen(9010);
// Client
//####################################################################################################
// Send file to proxy
var client = new net.Socket();
// connect to proxy
client.connect('9000', '127.0.0.1', function () {
console.log('Connection to proxy opened');
});
// send data to proxy
myFile.pipe(client);
// read response from taget
client.on('data', function(data) {
console.log('Response: ' + data);
// close the client socket completely
client.destroy();
});
// Add a 'close' event handler for the client socket
client.on('close', function() {
console.log('Connection to proxy closed');
});
Any hint to a good tutorial is also welcome.
TMOE

Answer 1

socket.write() already uses streams under the hood so you don't need to do anything special. Just send it the usual Buffer object or string and it will use a stream.
From the current source code of io.js, here's what happens when you use socket.write():
Socket.prototype.write = function(chunk, encoding, cb) {
if (typeof chunk !== 'string' && !(chunk instanceof Buffer))
throw new TypeError('invalid data');
return stream.Duplex.prototype.write.apply(this, arguments);
};
And stream is declared like this:
const stream = require('stream');
Apologies if I've misunderstood your question/requirements! By all means, clarify if I have misunderstood you and I'll try again (or delete this answer so it's not a distraction).