Define socket.io once and use it in any view I want?

app.js

// Setup basic express server
var express = require('express');
var app = express();

// Spool up server
var server = app.listen(app.get('port'), function() {
  console.log('App listening on port %d', app.get('port'));
});

// Import socket_api
var socket_api = require('./socket_api').mount(server);

var home = require('./routes/home')(socket_api)
app.use('/', home);               // mount middleware for site root

home.js

var express = require('express');
var router = express.Router();

module.exports = function(socket_api) {
  // INDEX
  router.get('/', function(request, response, next) {
    response.render('home');

    // I WANT TO BE ABLE TO USE SOCKET.IO HERE AS DEFINED IN SOCKET_API SO I AM NOT IMPORTING IT
    // CONSTANTLY. IF ALTERATIONS HAVE TO BE MADE TO ACCOMODATE IMPORTING AND DEFINING SOCKET.IO ONCE SURE
    // BUT CONSTANTLY IMPORTING IT REQUIRES EXPORTING APP.JS AND EXPOSING `SERVER` WHICH ISN'T DRY.
    // E.G. TO HAVE io.on('connection') ETC RIGHT HERE
  });
  
  return router
}

socket_api.js

var socketio = require('socket.io');

module.exports.mount = function(server) {
  io = socketio.listen(server);

  io.on('connection', function(socket) {
    console.log('Connection!');
    socket.on('disconnect', function() {
      console.log('Disconnection!');
    });

    socket.on('clicked!', function() {
      console.log("asddsasdaads");
    });
  });

  return io;
}

Hello, Could you use socket inside the routes? Is there any caveat to it?