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

Inspecting your container build results

In previous chapters, we discussed in detail the container build process and learned how to create custom images using Dockerfiles/Containerfiles or Buildah-native commands. We also illustrated how the second approach helps achieve a greater degree of control of the build workflow.

This section helps provide some best practices to inspect the build results and understand potentially related issues.

Troubleshooting builds from Dockerfiles

When using Podman or Buildah to run a build based on a Dockerfile/Containerfile, the build process prints all the instructions' outputs and related errors on the terminal stdout. For all RUN instructions, errors generated from the executed commands are propagated and printed for debugging purposes.

Let's now try to test some potential build issues. This is not an exhaustive list of errors; the purpose is to provide a method to analyze the root cause.

The first example shows a minimal...