Part 2 of the book covers the underlying design of Podman. Chapter 5 explains all of the different configuration files used with Podman. Podman is developed using multiple different container libraries, each with a distinct method of configuration. You learn how to configure your container storage and where to store your containers as well as images. You also learn how to configure the container registries you use for pulling and pushing container images. Finally, you learn about containers.conf, which allows you to fully customize the way Podman works. Basically, you can change the default values used by the Podman CLI for every container you create.
Chapter 6 then takes a deep dive into how rootless containers work. Rootless containers are a key feature of Podman that allows you to fully work with containers and pods as a normal user, without any additional privileges. This chapter also introduces you to how the user namespace works and allows you to use more than a single UID within a container, without being root. Finally, you will learn some of the problems with rootless containers and how to work around them.