For Meteor-Files https://github.com/VeliovGroup/Meteor-Files http upload simple example

Meteor-Files Http upload Example

import { Meteor } from 'meteor/meteor';
import { Accounts } from 'meteor/accounts-base';
import { FilesCollection } from 'meteor/ostrio:files';
import  * as fs from 'fs';
import  multer  from 'multer';

export const Avatars = new FilesCollection({
  collectionName: 'avatars',
  allowClientCode: false,
  onBeforeUpload: function (file) {
    // Allow upload files under 10MB, and only in png/jpg/jpeg formats
    if (file.size <= 10485760 && /png|jpg|jpeg/i.test(file.extension)) {
      return true;
    } else {
      return 'Please upload image, with size equal or less than 10MB';
    }
  },
  downloadRoute: 'cdn/storage/avatars',
  storagePath: "/app/uploads/images/avatars",
  public: true
});


if (Meteor.isServer) {
  const _multerInstanceConfig = { dest: '/tmp' }; // Temp dir for multer
  const _multerInstance = multer(_multerInstanceConfig);

  WebApp.connectHandlers.use(_multerInstance.single('dp')).use("/api/v1/avatar/upload", Meteor.bindEnvironment(function(req, res, next) {
    if (req.file !== undefined && req.file.mimetype.substr(0, 6) == 'image/' && req.headers.authtoken.length) {
      
      const hashedToken = Accounts._hashLoginToken(req.headers.authtoken);
      const user = Meteor.users.findOne({ 'services.resume.loginTokens.hashedToken': hashedToken });

      if (user) {
        Avatars.remove({ 'meta.userId': user._id });
        fs.stat(req.file.path, function (_statError, _statData) {
          const _addFileMeta = {
            fileName: req.file.originalname,
            type: req.file.mimetype,
            size: req.file.size,
            meta: {
              userId: user._id,
              username: user.username
            }
          };

          fs.readFile(req.file.path, function (_readError, _readData) {
            if (_readError) {
              console.log(_readError);
            } else {
              Avatars.write(_readData, _addFileMeta, function (_uploadError, _uploadData) {
                if (_uploadError) {
                  console.log(_uploadError);
                } else {
                  console.log('upload data=', _uploadData); 
                  fs.unlink(req.file.path); // remove temp upload
                }
              });
            }
          });
        });
      }
    }
    res.end();
  }))
}

Hi! Just uploaded a sample repo here https://github.com/mgscreativa/React-Native-Upload-Files-to-Meteor-Server