proxy-sr

Problem statement

For this first exercise, you are going to simply print all the requests that will be passing between VLC and the media server. To do so, you are going to create a local server. This local server will serve as a relay between VLC and the CDN. In order to make it work, you will have to consider the following points:

• You will give your local server URL to VLC so it hit your local server instead of the CDN
• You will request the CDN yourself and send back the result of each request to VLC through your server
• You will also need to give the original stream URL to your server when starting it, so it will know how to request content from the CDN
• Your server might need to be re-launched for each new stream to feed it with the right URL

The launch procedure will look like this:

1. Launch your local server with the stream URL
2. Then start a network video from VLC pointing to your local server

Each request is going to be printed two times, when it arrives from the player and when the CDN is going to answer to it.

The expected output will contain the following:

• [IN] When a request is intercepted from VLC
• [OUT] (ms) When the CDN answers and we send back the answer to the player

Prerequisites

• C++17 compiler
• CMake (version compatible with C++17 needed)
• libssl
• pthread

How to build

$ cmake -S . -B build
$ cmake --build build

$ cd build && ctest && cd -
$ ./build/proxy-sr
Usage: ./build/proxy-sr <uri>

Proxy server.
Try: ./build/proxy-sr https://bitdash-a.akamaihd.net/content/MI201109210084_1/m3u8s/f08e80da-bf1d-4e3d-8899-f0f6155f6efa.m3u8

Error: missing input.

Decision making

There are many reasons why I choose Python for the first implementation, here are some:

• Crossplatform, as long as you have Python installed, the proxy will work
• The standard library is HUGE and will help me to iterate faster on the problem
• You don't need root access to the server

Once I'll have a good enough understanding of the problem and how to solve it I will start the C++ implementation.

HTTP library

I use the cpp-httplib library mainly because it is a single-file header-only, thus easy to setup.