What you need for this book
The book is written with the help of Ubuntu server 16.04 and few virtual machines with VirtualBox. The recipes should work fine with Ubuntu version 14.04 and higher. For most of the recipes, a minimum hardware configuration of 512 MB memory with single CPU is enough. However, a few recipes such as OpenStack installation require additional hardware resources. The specific requirements are given in the respective recipes, if any.
Feel free to use any virtualization tool of your choice. Also, you can skip the local set up and use cloud servers. Many cloud providers give free introductory service for limited period. You can use these services to test your setup.