Book Image

Podman for DevOps

By : Alessandro Arrichiello, Gianni Salinetti
Book Image

Podman for DevOps

By: Alessandro Arrichiello, Gianni Salinetti

Overview of this book

As containers have become the new de facto standard for packaging applications and their dependencies, understanding how to implement, build, and manage them is now an essential skill for developers, system administrators, and SRE/operations teams. Podman and its companion tools Buildah and Skopeo make a great toolset to boost the development, execution, and management of containerized applications. Starting with the basic concepts of containerization and its underlying technology, this book will help you get your first container up and running with Podman. You'll explore the complete toolkit and go over the development of new containers, their lifecycle management, troubleshooting, and security aspects. Together with Podman, the book illustrates Buildah and Skopeo to complete the tools ecosystem and cover the complete workflow for building, releasing, and managing optimized container images. Podman for DevOps provides a comprehensive view of the full-stack container technology and its relationship with the operating system foundations, along with crucial topics such as networking, monitoring, and integration with systemd, docker-compose, and Kubernetes. By the end of this DevOps book, you'll have developed the skills needed to build and package your applications inside containers as well as to deploy, manage, and integrate them with system services.
Table of Contents (19 chapters)
1
Section 1: From Theory to Practice: Running Containers with Podman
7
Section 2: Building Containers from Scratch with Buildah
12
Section 3: Managing and Integrating Containers Securely

Preparing your environment

Once the Podman packages have been installed, Podman is ready to be used out of the box. However, some minor customizations can be useful to provide better interoperability with external registries or to customize runtime behaviors.

Customizing the container registries search list

Podman searches for and downloads images from a list of trusted container registries. The /etc/containers/registries.conf file is a TOML config file that can be used to customize whitelisted registries that are allowed to be searched and used as image sources, as well as registry mirroring and insecure registries without TLS termination.

In this config file, the unqualified-search-registries key is populated with an array of unqualified registries with no specification regarding images repositories and tags.

On a Fedora system, with a new installation of Podman, this key has the following content:

unqualified-search-registries = ["registry.fedoraproject.org...