Disclaimer: This is a series about me, creating a web application in Node.js. The completed example is available here.
- Beginning Node.js - callbacks - part 1
- Beginning Node.js - REST API with Express 4 - part 2
- Beginning Node.js - REST API with a Mongodb backend - part 3
- Beginning Node.js - REST API with a Mongodb backend (refactoring) - part 4
- Beginning Node.js - Testing - part 5
- Beginning Node.js - local authentication with Passport-Local Mongoose- part 6
I have a deep respect for all those developers out there that write fantastic modules I can use in my projects. One little gem is passport-local-mongoose. I've written about it before but as you see I'm doing it again.
What is passport-local-mongoose?
You can plug-in passport-local-mongoose into your Mongoose Userschema. This decorates the User object with a set of methods. E.g.
- authenticate
- register
- setPassword
- serialize
- deserialize
It also hashes the passwords. This saves a lot of work.
What we should work on
- Users should be able to register
- Users should be able to authenticate
- Users should be able to change their password
- Users should be able to change their e-mail address
- There should be a 'forgot password' procedure
- Users should be able to delete their accounts
This article covers only 'register' and 'authenticate'. You can go ahead and clone the restaurant github repo for a full example.
To add local authentication to your app you'll need to run:
var mongoose = require('mongoose'),
    Schema = mongoose.Schema,
    passportLocalMongoose = require('passport-local-mongoose');
var User = new Schema({});
var options = ({missingPasswordError: "Foutief password"});
User.plugin(passportLocalMongoose,options);
module.exports = mongoose.model('User', User)
Of course, you may add your own properties to the model:
var mongoose = require('mongoose'),
    Schema = mongoose.Schema,
    passportLocalMongoose = require('passport-local-mongoose');
var User = new Schema({
    uuid: {
        type: String,
        required: false
    },
    firstname: {
        type: String,
        required: true
    },
    active: {
        type: String,
        required: false
    }
});
var options = ({missingPasswordError: "Wrong password"});
User.plugin(passportLocalMongoose,options);
module.exports = mongoose.model('User', User)
Now let's hook up Passport in our app.
Controller
Let's create a user controller which contains the register, the login and the getLogin functions (to check if a user has logged in).
Create a file named controller.user.js and put it in the app folder:
var mongoose = require('mongoose');
var User = require('./model.user');
exports.register = function (req, res) {
    console.log("registering: " + req.body.firstName);
    User.register(new User({
        username: req.body.username,
        firstname: req.body.firstname
    }), req.body.password, function (err, user) {
        if (err) {
            console.log(err);
            return res.send(err);
        } else {
            res.send({
                success: true,
                user: user
            });
        }
    });
};
exports.login = function (req, res, next) {
    User.authenticate()(req.body.username, req.body.password, function (err, user, options) {
        if (err) return next(err);
        if (user === false) {
            res.send({
                message: options.message,
                success: false
            });
        } else {
            req.login(user, function (err) {
                res.send({
                    success: true,
                    user: user
                });
            });
        }
    });
};
exports.getLogin = function (req, res) {
    console.log(req.user);
    if (req.user) {
        return res.send({
            success: true,
            user: req.user
        });
    } //res.send(500, {status:500, message: 'internal error', type:'internal'}); == deprecated
    res.send({
        success: false,
        message: 'not authorized'
    });
};
What happens?
1. User.authenticate and User.register:
The User.authenticate and User.register are functions we get from passport-local-mongoose. I just took this code as an example.
2. Check if a user is logged in with 'if(req.user)'
If a user is logged in, the req.user property is populated with the user object.
So if it exists, the user is logged in.
Routes
//mongodb
var mongoose = require('mongoose');
var User = require('./model.user');
var users = require('./controller.user');
var passport = require('passport');
var LocalStrategy = require('passport-local').Strategy;
var cookieParser = require('cookie-parser');
var session = require('express-session');
module.exports = function (app) {
    //initialize passport
    passport.use(User.createStrategy());
    // use static serialize and deserialize of model for passport session support
    passport.serializeUser(User.serializeUser());
    passport.deserializeUser(User.deserializeUser());
    //need this according to passport guide
    app.use(cookieParser());
    app.use(session({
        secret: 'the princess and the frog',
        saveUninitialized: true,
        resave: true
    }));
    app.use(passport.initialize());
    app.use(passport.session());
    //routes
    app.route('/register').post(users.register);
    app.route('/login').post(users.login);
    app.route('/login').get(users.getlogin);
   
   
};
Add this file to main.js, like so:
require('./app/routes.user')(app);
This will be your completed main.js:
var express = require('express');
var app = express();
var bodyparser = require('body-parser');
var mongoose = require('mongoose');
app.use(bodyparser.urlencoded({
  extended: true
}));
app.use(bodyparser.json());
mongoose.connect('mongodb://localhost:27017/restaurant');
require('./app/routes.food')(app);
require('./app/routes.user')(app);
app.use(express.static(__dirname + '/public'));
app.set('port', process.env.PORT || 3001);
app.listen(app.get('port'));
console.log("the server is running on http://localhost:" + app.get('port'));
Let's try this
Install Postman or another REST API test tool.
- Don't forget to configure the headers: Content-Type application/json
First, let's register a user (click POST):
Second, let's login:
Check the login status:
The end of this series
This is where this series end. I hope anyone will enjoy this and at least learns  something from my struggles. I know I did!
Your feedback is more than welcome by the way.  



Hello Jaqueline and thank you for the useful article! I have the following question, I see in your github repo (https://github.com/jacqinthebox/Restaurant/blob/master/app/controller.user.js) how you use the setPassword method of passport-local-mongoose. My question is how to I create a password change form, where a user would submit in the same form his old password and his new one. Obviously for this to work I would have to check his old password to see that it matches to the one already in the database and if it matched I would update his password using the setPassword method, my question is what is the optimal way taking into account security issues, to implement this first step (password comparison).