text: const express = require('express');
  const mongoose = require('mongoose');
  const cors = require('cors');
  const http = require('http');
  const routes = require('./routes');
  const { setupWebsocket } = require('./websocket');
  const fs = require('fs');
  
  const app = express();
  const server = http.Server(app);
  
  setupWebsocket(server);
  
  const config_object = fs.readFileSync('./config.json');
  const content_config = JSON.parse(config_object);
  
  const uri_mongodb = 'mongodb://' + content_config.URI_MONGODB;
  
  mongoose.connect(uri_mongodb, {
      useCreateIndex: true,
      useNewUrlParser: true,
      useUnifiedTopology: true
  });
  
  app.use(cors());
  app.use(express.json());
  app.use(routes);
  mongoose.set('useFindAndModify', false);
  
  server.listen(content_config.PORT_BACKEND);
  