Building web apps from scratch - Getting Started - Part 0

In the past few years, I had some fun studying how web apps are built from the ground up. It's been a great journey so I decided to share what I learned by making a series of posts showing how one can build a web app from scratch. We will build a simple social network featuring posting articles and following other users. If you follow along, by the end you'll have a fully functional website ready for real users!

This is the first time undertaking such an ambitious project, so I welcome any feedback :)

We'll be using the C programming language for everything, since it's low level enough to do things efficiently and not very opinionated. The libraries we will use are:

• BearSSL for encryption
• SQLite as database

but we can worry about that later.

Prerequisites

To follow along, you will need:

• A good grasp of C programming
• An idea of how HTTP works: what is a request, a response, and their general syntax.

Environment Setup

Our setup won't be very fancy. We will use a regular code editor to write our code and a terminal to build it. All of the code will work on both Linux and Windows.

On Linux, you must install:

• gcc and make for building our application
• gdb, valgrind, and strace for debugging

On Windows, you have two options:

1. Use WSL to simulate a Linux environment
2. Go native

WSL is harder to set up, but you will have access to the tools I listed above. Any considerations made for Linux will also apply to you.

If you still want to go native, then you should download w64devkit, which is is an unix-like environment for Windows built by the awesome author of nullprogram.com. It contains gcc, gdb, make and some other utilities.

Roadmap

We will start by building a blocking web server with the socket interface provided by the operating system. We will then add a database and implement the first version of our application. You could host this version online, but only as a test, since there will be no encryption. Then, we will reorganize our server to make it non-blocking, greatly increasing how many requests the server can handle at a given time. Finally, we will add encryption.

But before all of that, I decided to offer an overview of how networks work. This will give you a sense of what the OS is doing for us. So in the next post we will go over the general structure of the internet and the protocols it uses.