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

Migrating existing images and playing with a command's alias

Podman has one great feature that lets any previous Docker user easily adapt and switch to it – complete command-line interface (CLI) compatibility with Docker.

Let's demonstrate this CLI compatibility with Docker by creating a shell command alias for the docker command:

# alias docker=podman
# docker
Error: missing command 'podman COMMAND'
Try 'podman --help' for more information.

As you can see, we have created a command alias that binds the podman command to the docker one. If we try to execute the docker command after setting the alias, the output is returned from the podman command instead.

Let's try this out on the newly created alias by running a container:

# docker run --rm -it docker.io/wernight/funbox nyancat

We should see something very funny – a running cat, similar to the one shown in the following screenshot:

Figure 13.1...