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nginx / sails.js: incomplete file upload

由 老子叫甜甜 提交于 2019-12-08 19:12:34

From the nginx debug log it seems that the problem is due to early return of response from the backend - note that in the last sendfile() call nginx was able to send only 2488810 out of 12584911 bytes it tried to:

...
2014/12/03 01:57:23 [debug] 39583#0: *1 chain writer in: 00000000011CC5D0
2014/12/03 01:57:23 [debug] 39583#0: *1 sendfile: @2776864 12584911
2014/12/03 01:57:23 [debug] 39583#0: *1 sendfile: 2488810, @2776864 2488810:12584911
2014/12/03 01:57:23 [debug] 39583#0: *1 chain writer out: 00000000011CC5D0
2014/12/03 01:57:23 [debug] 39583#0: *1 event timer del: 35: 1417568303245
2014/12/03 01:57:23 [debug] 39583#0: *1 event timer add: 35: 60000:1417568303254
2014/12/03 01:57:23 [debug] 39583#0: *1 http upstream request: "/admin/edit_object/6?"
2014/12/03 01:57:23 [debug] 39583#0: *1 http upstream process header
2014/12/03 01:57:23 [debug] 39583#0: *1 malloc: 00000000011CD000:262144
2014/12/03 01:57:23 [debug] 39583#0: *1 recv: fd:35 369 of 262144
2014/12/03 01:57:23 [debug] 39583#0: *1 http proxy status 200 "200 OK"
2014/12/03 01:57:23 [debug] 39583#0: *1 http proxy header: "X-Powered-By: Sails <sailsjs.org>"
...

And the backend returned an 200 OK answer. At this point nginx thinks that there is no reason to send the rest of the request body and stops sending it - this what causes incomplete uploaded files. Additionally, you have keepalive upstream connections configured, and you are hitting this bug - and this is why you see headers of an unrelated request.

Teaching the backend code to only send a response after the request is fully read, as in your test code, should resolve the problem.

So, the solution i found is to hack a bodyparser which use formidable.

No more problem :).

For the record, it was a bit of a hack to switch the bodyparser in the middlewares:

config/http.js

module.exports.http = {
  middleware: {
    bodyParser: false,
    cbodyParser: require('../bodyParser')(
        {urls: [/\/admin\/edit_object/]}),
    order: [
     'startRequestTimer',
     'cookieParser',
     'session',
     'cbodyParser',
     'handleBodyParserError',
     'compress',
     'methodOverride',
     'poweredBy',
     '$custom',
     'router',
     'www',
     'favicon',
     '404',
     '500'
   ],    
  }
};

bodyparser.js:

/**
 * Module dependencies
  // Configure body parser components
 */
var _ = require('lodash');
var util = require('util');
var formidable = require('formidable');

function mime(req) {
  var str = req.headers['content-type'] || '';
  return str.split(';')[0];
}

function parseMultipart(req, res, next) {
  req.form = new formidable.IncomingForm();
  req.form.uploadDir = sails.config.data.__uploadData;
  req.form.maxFieldsSize = sails.config.maxsize;
  req.form.multiple = true;
  // res.setTimeout(0);
  req.form.parse(req, function(err, fields, files) {
    if (err)
        return next(err);
    else {
      req.files = files;
      req.fields = fields;
      req.body = extend(fields, files);
      next();
    }
  });
}

function extend(target) {
  var key, obj;
  for (var i = 1, l = arguments.length; i < l; i++) {
    if ((obj = arguments[i])) {
      for (key in obj)
        target[key] = obj[key];
    }
  }
  return target;
}

function disable_parser(opts, req, res)  {
    var matched = false;
    try {
        var method = null;
        try {method = req.method.toLowerCase();}
        catch(err){ /* */}
        if(method) {
            _(opts.urls).forEach(function(turl) {
                if (method === 'post' && req.url.match(turl)) {
                    // console.log("matched"+ req.url);
                    if(!matched) matched = true;
                };});
        }
    } catch(err) { debug(err);/* pass */ }
    return matched;
}

module.exports = function toParseHTTPBody(options) {
  options = options || {};
  var bodyparser = require('skipper')(options);
  // NAME of anynonymous func IS IMPORTANT (same as the middleware in config) !!!
  return function cbodyParser(req, res, next) {
    var err_hdler = function(err) {};
    if (disable_parser(options, req, res) && mime(req) == 'multipart/form-data') {
        return parseMultipart(req, res, next);
    } else {
        return bodyparser(req, res, next);
    }
  };
};

Indeed, sails let to think that we can override the bodyParser, but we cant as it will result in an anonymous function but the express router only map "named" function...

We faced a similar issue. I dont know if our solution will work for you or not, but here goes.

For very large files, the csrf gets left out of request packet. So we need to send the csrf in request header rather than request body. For that we changed the XMLHttpRequest a little bit.

/*
Putting csrf in Header as some large
files need this mechanism to upload
*/
(function() {
  var send = XMLHttpRequest.prototype.send,
  token = csrfToken;   //csrfToken is global
  XMLHttpRequest.prototype.send = function(data) {
    this.setRequestHeader('X-CSRF-Token', token);
    return send.apply(this, arguments);
  };
}());

From now, every request will have csrf in the header. This solved the problem for us. Hope this helps you too.

标签
node.js
nginx
sails.js
skipper
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