$scope.signIn = function (username, password) {
    $http.post('/login', {username: username, password: password})
        .then(function (res) {
            if(res.data.success) {
                console.log('Logged in');
            } else {
                console.log('error logging in');
            }
        })
};

app.post('/login', function (req, res, next) {

    var auth = passport.authenticate('local', function (err, user) {
        if(err) { return next(err); }
        if(!user) { res.send({success: false, user: user}); }

        req.login(user, function (err) {
            if(err) { return next(err); }
            res.render('index', { success: true, user: user });
        });
    });

    auth(req, res, next);
});

.navbar-right(ng-controller='navbarLoginCtrl')
form.navbar-form(action='/login' method='post')
    .form-group
        input.form-control(name='username' placeholder='username', ng-model='username' required)
    .form-group
        input.form-control(name='password' type='password', placeholder='password', ng-model='password' required)
    button.btn.btn-default(type='submit' value="Submit") Sign in

.navbar-right(ng-controller='navbarLoginCtrl')
form.navbar-form
    .form-group
        input.form-control(name='username' placeholder='username', ng-model='username' required)
    .form-group
        input.form-control(name='password' type='password', placeholder='password', ng-model='password' required)
    button.btn.btn-default(ng-click='signIn(username, password)') Sign in

var User = mongoose.model('User');

passport.serializeUser(function (user, done) {
    if (user) {
        done(null, user._id);
    }
});

passport.deserializeUser(function (id, done) {

    User.findOne({_id: id}).exec(function (err, user) {
        if(user) {
            return done(null, user);
        } else {
            return done(null, false);
        }
    });
});

passport.use(new LocalStrategy(
    function (username, password, done) {
        User.findOne({username: username}, function (err, user) {
            if (user) return done(null, user);
            else return done(null, false);
        });
    }
));