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

Setting up the prerequisites for the host operating system

As we saw in Chapter 1, Introduction to Container Technology, containers were born to help simplify and create system services that can be distributed on standalone hosts.

In the following sections, we will learn how to run MariaDB and a GIT service in containers while managing those containers like any other service – that is, through Systemd and the systemctl command.

First, let's introduce systemd, a system and service manager for Linux that runs as the first process on boot (as PID 1) and acts as an init system that brings up and maintains userspace services. Once a new user logs in to the host system, separate instances are executed to start their services.

The systemd daemon starts services and ensures priority with a dependency system between various entities called units. There are 11 different types of units.

Fedora 34 and later has systemd enabled and running by default. We can check if it...