In the fourth and final (phew!) part of my guide to Docker, we'll be meeting Docker Compose, which is the smart way to run multi-container apps and gives us greater control over them.

Welcome to part three of my four-part guide to Docker, where we're building a PHP-based to-do app. This time out we'll look at multi-container apps and introduce a second, MySQL container to store our data!

In this, the second part of my Docker tutorial, we'll be building a PHP-based to-do app. Along the way we'll meet some new Docker concepts, including volumes, which are the key to developing within Docker.

Docker answers the question, "what's the best way to ship an app including not just its content but also its environment (runtime)?" In this four-part guide we'll be learning Docker via a to-do app built in PHP and MySQL.