amazon s3 - How do you stream an upload to S3 via node.js and show progress to user? -

the goal to:

1. be able upload file browser
2. be able stream upload directly s3
3. relay upload progress browser

it took me while figure out (and didn't quite find answer 3 on stackoverflow yet) posting answer in case else has same problem.

i'm open suggestions better solutions (the speeds on mine pretty horrible).

on frontend html

<input type="file" class="file" name="files[]"> 

on frontend js

require('blueimp-file-upload'); var socket = require('socket.io-client');  var filesize; var socketid;  // socket used transmit percent uploaded server socket.connect()   // when socket gives unique id save   // can identify client   .on('id', function (data) {     socketid = data;   })    .on('uploadprogress', function (data){     // can show progress bar percentage      var pct = data.loaded / filesize;   });  $('.file')     .change(function (){         // save file size can calculate perfectage         filesize = this.files[0].size;       })     .fileupload({         datatype: 'json',     })     .fileupload('option', {         url: '/upload?socketid=' + socketid     }); 

on server

var busboy = require('busboy'); var aws = require('aws-sdk'); var socket = require('socket.io'); var express = require('express'); var http = require('http');  // set express var app = express(); var server = http     .server(app)     .listen(80);  var io = socket(server);  // keeps track of open sockets var sockets = {};  io.on('connection', function (socket) {   var uniqueid = _.random(0, 100000000);   app.socket[uniqueid] = socket;   socket.emit('id', uniqueid); });  // set upload route app.post('/upload', function (req, res) {         aws.config.update({             appkey: '',             jskey: '',         });         var s3 = new aws.s3();          var busboy = new busboy({             headers: req.headers          });      busboy.on('file', function(fieldname, file, filename) {         s3.upload({             bucket: 'bucketname',             key: new date().gettime() + filename,             body: file //stream         }, function(err, file){             res.json({                 success: true             });         }).on('httpuploadprogress', function(evt) {              //emit progress             sockets[req.query.socketid].emit('uploadprogress', evt);         });     });      req.pipe(busboy); });