1. Introduction

This tutorial aims to guide you through the process of deploying your Express.js and MongoDB application to a production server. Doing so will make your application accessible to users on the internet.

By the end of this tutorial, you will learn how to prepare your application for deployment, how to configure your MongoDB database, and how to deploy your application using Heroku.

Prerequisites for this tutorial include basic knowledge of Node.js, Express.js, MongoDB, and Git.

2. Step-by-Step Guide

2.1 Preparing your application for deployment

Before deploying your application, you need to ensure that it is ready for production. This includes setting up a production database, adding environment variables, and handling any other configurations that your application might need for production.

2.2 Configuring MongoDB for production

You need to set up a MongoDB database that your application can connect to in production. MongoDB Atlas is a cloud database service that you can use for this purpose. After you create a MongoDB Atlas account and set up a new cluster, you can get a connection string that your application will use to connect to the database.

2.3 Deploying your application

Heroku is a cloud platform that you can use to deploy your application. After you create a Heroku account, you can create a new application and connect your GitHub repository to it. Heroku will then build your application and deploy it.

3. Code Examples

3.1 Configuring MongoDB for production

// Import mongoose
const mongoose = require('mongoose');

// Connect to MongoDB Atlas
mongoose.connect(process.env.MONGODB_URI, {
  useNewUrlParser: true,
  useUnifiedTopology: true,
});

In the code snippet above, process.env.MONGODB_URI is the MongoDB Atlas connection string. It is stored in an environment variable so that it is not exposed in your code.

3.2 Deploying your application

After you have pushed your code to your GitHub repository, you can deploy your application on Heroku.

# Log in to Heroku
heroku login

# Create a new Heroku application
heroku create your-app-name

# Push your code to Heroku
git push heroku master

4. Summary

In this tutorial, you have learned how to prepare your Express.js and MongoDB application for deployment, how to set up a MongoDB Atlas database for production, and how to deploy your application using Heroku.

Next, you can learn more about monitoring and scaling your application in production. You can also explore other deployment options, such as AWS or Azure.

5. Practice Exercises

5.1 Exercise 1

Create a simple Express.js application that connects to a MongoDB database and deploy it to Heroku.

5.2 Exercise 2

Modify your application to use environment variables for sensitive information, such as your MongoDB connection string.

5.3 Exercise 3

Add error handling to your application to ensure that it can recover gracefully from errors in production.

Remember, practice is crucial in mastering web development. Keep building and deploying applications to reinforce what you've learned.