Mongoose + Heroku + mLab

Configurate Heroku with:

heroku config:set MONGOLAB_URI=mongodb://[username]:[password]@xx000000.mlab.com:00000/[project-name]

Add to app.js:

const mongodbUri = process.env.MONGOLAB_URI;

mongoose.connect(mongodbUri, (err, res) => {
    if (err) {
        console.log(err);
    } else {
        console.log('success!!!!!!!!!');
    }
});

At the bottom:

const port = process.env.PORT

app.listen(process.env.PORT);