How to Deploy a Node.js Express & MongoDB App

You’ve built your Express server and mongoose models on your local machine. Now it's time to put it on the web so a frontend SPA or mobile client can communicate with it.

Prepare Your MongoDB Connection String

Ensure that in your `server.js` or `app.js`, you are reading the database URI from the environment variables rather than hardcoding it:

mongoose.connect(process.env.MONGO_URI)
  .then(() => console.log('Database connected'))
  .catch(err => console.error(err));

Use the Dynamic PORT

Your cloud environment will assign a port dynamically. Allow your app to listen on the cloud's port, rather than hardcoding `3000`.

const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
  console.log(`Server listening on port ${PORT}`);
});

Cloud Deployment

1. Create an account in MongoDB Atlas (it’s free), set up your database, and get your connection string. Be sure to whitelist IP address `0.0.0.0/0` so your cloud server can connect.
2. In your Remoud dashboard, create a new app from your GitHub repository.
3. In your App's Settings panel, add an Environment Variable with the key `MONGO_URI` and paste the connection string you got from Atlas.
4. Click Save. Your environment is secure.
5. Wait for the container to build via `npm install` and start your app via `npm start`.