エクスプレスセッションはミドルウェアでは定義されていませんが、コントローラーで定義されています

セッションがミドルウェアでは定義されていないが、コントローラーでは定義されているエクスプレスセッションで問題が発生しました。

これは、コントローラーにセッションを配置するときの私のコードです

exports.login = (req, res, next) => {
    User.find({username: req.body.username}, (err, data) => {
        if (data.length === 1) {
            const password = data[0]['password']
            bcrypt.compare(req.body.password, password, (err, check) => {
                if (err) console.error(err)
                if (check) {
                    req.session.username = data[0]['username']
                    req.session.userid = data[0]['id']
                    console.log("session when logged in => " + req.session.username) //the session is defined
                    res.redirect('/dashboard')
                } else {
                    res.status(304).send('password salah')
                }
            });
        } else {
            res.status(304).send('username / password tidak tersedia')
        }
    })
}

しかし、私がセッションをミドルウェアでチェックすると

const usermiddleware = (req, res, next) => {
    console.log(req.session.username + " => session in middleware") //undefined
    if (req.session.username) {
        next()
    } else {
        res.redirect('/') //runs here
    }
}

これは私のapp.jsです

let createError = require('http-errors');
let express = require('express');
let path = require('path');
let cookieParser = require('cookie-parser');
let logger = require('morgan');
let bodyparser = require('body-parser');
let mongoose = require('mongoose');
let session = require('express-session')
var socket_io = require('socket.io');
let app = express();
let io = socket_io();
app.io = io;


io.on("connection", socket => {
    console.log("A user connected");
});
app.use((req, res, next) => {
    req.io = io;
    next()
})

app.use(session({
    secret: 'asd123',
    saveUninitialized: true,
    resave: true,
    cookie: {
        secure: true
    } 
}))
app.use((req, res, next) => {
    app.locals.username = req.session.username || ""
    app.locals.userid = req.session.userid || ""
    next()
})

app.use((req, res, next) => {
    mongoose.connect('mongodb://localhost/inventory', {
        useNewUrlParser: true,
        keepAlive: true,
        keepAliveInitialDelay: 300000
    });
    const db = mongoose.connection;
    db.on('error', console.error.bind(console, 'connection error:'));
    db.once('open', () => {
        req.db = mongoose.connection;
        next()
    });
})

let indexRouter = require('./routes/index');
let usersRouter = require('./routes/users');


// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');

app.use(logger('dev'));
app.use(bodyparser.json());
app.use(bodyparser.urlencoded({extended: true}));
app.use(express.json());
app.use(express.urlencoded({extended: false}));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.use('/', indexRouter);
app.use('/users', usersRouter);

// catch 404 and forward to error handler
app.use((req, res, next) => {
    next(createError(404));
});

// error handler
app.use(function (err, req, res, next) {
    // set locals, only providing error in development
    res.locals.message = err.message;
    res.locals.error = req.app.get('env') === 'development' ? err : {};

    // render the error page
    res.status(err.status || 500);
    res.render('error');
});

module.exports = app;

これは私のフルインデックスルーターです

let express = require('express');
let router = express.Router();
const usermiddleware = (req, res, next) => {
    console.log(req.session.username + " => session middleware")
    if (req.session.username) {
        next()
    } else {
        res.redirect('/')
    }
}

const auth = require('../controller/auth');
const page = require('../controller/page');

router.get('/', page.index);
router.post('/register', auth.register);
router.post('/login', auth.login);
router.get('/logout', auth.logout)

router.get('/dashboard', usermiddleware, page.dashboard);
router.get('/admin', usermiddleware, usermiddleware, page.admin);

module.exports = router;

注：ソケットioとmonggoseを備えたエクスプレスジェネレーターでエクスプレスセッションを使用しています