The New Kid on the Block: What is Podman and its Definition in the Tech World

In recent years, container technology has transformed the IT industry and software development landscape, offering a more efficient and secure way of deploying applications. As part of this trend, Podman has emerged as a popular alternative to the widely used Docker platform. With adoption rates steadily increasing, it has become crucial for organizations to understand the key benefits and best practices associated with this tool. In this glossary, we will discuss the basics of Podman, how it works, its key advantages, use cases, best practices, and recommended resources for learning more about this innovative technology.

“Podman is like running a marathon with containers, providing freedom, flexibility, and a lightweight solution for your container needs.” – Linus Torvalds

What is Podman? Definition of Pod Manager Tool

Podman, short for “Pod Manager,” is an open-source container management tool developed by Red Hat that aims to provide a more secure and lightweight alternative to Docker. Podman allows users to create, manage, and run containers without the need for a daemon, a critical distinction that sets it apart from Docker. This feature enables Podman to run containers with less overhead and security risk compared to other container platforms. Furthermore, Podman is compatible with the Open Container Initiative (OCI) standards, allowing seamless interoperability with other OCI-compliant container tools.

ℹ️ Synonyms: containerd, CRI-O, Docker, kubernetes, OCI, runc, Buildah, Skopeo

How it Works

At its core, Podman operates as a command-line tool for managing containers, with commands that closely resemble those of Docker. Users can create, start, stop, and remove containers using these familiar commands. However, unlike Docker, Podman does not rely on a central daemon to manage containers. Instead, it creates a direct connection between the container process and the host system, eliminating the need for a separate container runtime.

Podman also enables the creation of “pods,” groups of containers that share the same network namespace, storage, and cgroup settings. This feature allows containers within a pod to work together more closely and share resources, resembling the native behavior of Kubernetes, the popular container orchestration platform.

Benefits of using Podman

• Greater security: Podman’s daemonless architecture reduces the potential attack surface and eliminates the need for root privileges, resulting in a more secure container environment.
• Lower resource consumption: The absence of a daemon makes Podman lighter on system resources compared to Docker, enabling it to run with less overhead and faster startup times.
• Better compatibility: As an OCI-compliant tool, Podman works seamlessly with other container management systems like Kubernetes, ensuring smooth integration with existing container workflows.
• Simplified container management: Podman’s pod-based approach allows containers to share network and storage resources, simplifying container management and streamlining deployment processes.
• Ease of use: With commands similar to Docker, developers and operators can easily adapt to Podman without the need for extensive re-training.

Podman use cases

Podman’s versatility and ease of use make it well-suited for a variety of use cases, including:

Development and testing

Developers can use Podman to create and test containers on their local machines, simulating production environments without the need for dedicated test infrastructure.

Continuous integration and deployment (CI/CD)

Podman can be used as part of a CI/CD pipeline, allowing developers to build and deploy containers as part of an automated process, ensuring consistent and reliable application delivery.

Microservices architecture

Organizations implementing a microservices architecture can use Podman to manage their containers and pods, enabling greater scalability and flexibility in application development and deployment.

Multi-tenant environments

Podman’s enhanced security features make it an ideal choice for multi-tenant environments, such as shared development environments or cloud-based container platforms.

Code Examples

$ sudo apt-get update -y
$ sudo apt-get install -y software-properties-common uidmap
$ sudo add-apt-repository -y ppa:projectatomic/ppa
$ sudo apt-get update -y
$ sudo apt-get install -y podman

# Pull a container image
$ podman pull alpine

# Run a container
$ podman run -it alpine sh

# In the container
/ # echo "Hello from an Alpine container!"
Hello from an Alpine container!
/ # exit

# List containers
$ podman ps -a

CONTAINER ID  IMAGE                            COMMAND  CREATED             STATUS                       PORTS  NAMES
4b987a9b2e95  docker.io/library/alpine:latest  sh       About a minute ago  Exited (0) About a minute ago         kind_montalcini

# Remove a container
$ podman rm 4b987a9b2e95

4b987a9b2e951034d6dabbedf9ba814883428542bec5144f029c29a7aeb2d2dc

# List images
$ podman images

REPOSITORY         TAG     IMAGE ID      CREATED      SIZE
docker.io/alpine   latest  14119a10abf4  4 weeks ago  5.87 MB

# Remove an image
$ podman rmi 14119a10abf4

Untagged: docker.io/library/alpine:latest
Deleted: 14119a10abf48370778b9b0a36d0f97651076db8f6a2bdc66e7a1534419f97dd

Best Practices

To get the most out of Podman, it is essential to follow best practices that can help ensure the stability, security, and efficiency of your containerized applications. These include using the latest stable version of Podman, embracing its pod-based container management approach to streamline your workflow, setting appropriate resource limits, and adhering to the principle of least privilege by restricting access to containers and their resources. Additionally, organizations should always regularly monitor and audit container logs and other security-related information, as well as maintain well-documented and up-to-date container security policies.

Most recommended books about Podman

If you are interested in learning more about Podman, the following books are highly recommended:

1. Podman: The Definitive Guide by Brent Baude and Urvashi Mohnani: This comprehensive guide offers a deep dive into the world of Podman, covering all aspects of container management, from installation to advanced use cases.
2. From Docker to Podman: Transitioning to the Next Generation of Container Technology by Daniel J. Walsh: This book details the process of transitioning from Docker to Podman and provides insights into the key benefits and differences between the two platforms.
3. Podman in Action by Dusan Kostic: Offering practical examples and hands-on exercises, this book showcases Podman’s powerful features and provides step-by-step instructions for using them effectively.

Conclusion

As container technology continues to shape the IT industry, tools like Podman offer developers and operators a more secure and efficient way to manage their containerized applications. By understanding the core concepts of Podman, embracing its benefits, and following best practices, organizations can streamline their container workflows and improve the overall security and reliability of their applications. Additionally, resources such as books and online tutorials can aid in further understanding and leveraging the full potential of this powerful container management tool.

Tags: cli, containerization, deployment, development, docker.