Podman (An alternative to Docker !?!) 🦭

Exploring new tech

What is Podman? 🤔

Podman is a daemonless, open source, Linux native tool for finding, running, building, sharing, and deploying applications that use Open Containers Initiative (OCI) Containers and Container Images.

It operates very similar to Docker and is simple to set up.

Containers can run as root or in a rootless manner.

Documentation : https://podman.io/

How different from Docker? 🐳

The primary distinctions between Docker and Podman (Pod Manager Tool) are as follows:

Daemonless This characteristic distinguishes itself from Docker, which executes operations via a docker daemon. Podman is lightweight and does not require an instance to be active at all times in order to execute containers.
Rootless Podman can be operated as root or as a non-root user. We can run Podman containers as non-root users while being compatible with container running.
Pods The word Pods was coined by Kubernetes. Pods are groups of containers that run as close together as feasible. Podman includes this capability by default for running many containers concurrently.

Architecture 🏛:

Many individuals still refer to a container as a Docker container.

This does not accurately represent the existing container ecosystem. Docker generates OCI container images that may be used with different runtimes. Kubernetes is one such example, as is Podman.

As a result, the essential functionality of Podman and Docker overlaps. Both generate images that may be used to run containers by the other. On top of the basic containerization functionality, the two runtimes provide their own specializations.

Setup

And as its OCI-compliant, Podman can be used as a drop-in replacement for the better-known Docker runtime. Most Docker commands can be directly translated to Podman commands.

Simply put alias as, docker=podman on your machine and youre set

Installation of Podman is pretty straightforward over a Mac. If youre on other OS, follow this documentation. WSL over Windows works.

Request admin access from Self-service app and then open terminal. The Mac client is available through Homebrew.

brew install podman

To start the Podman-managed VM:

podman machine init

And then

podman machine start

Once the installation is complete, you can then verify the installation information using:

podman info

TLDR 📌

As stated before, Podman is just an alias for docker. Whatever commands you can execute with docker, you can execute with Podman.

Building an Image

podman build -t containername

Docker file :

Image building via the command :

podman build

Push Image

podman push registryname/imagename:tag

List images

podman images

Command screenshot :

Run container

podman run imagename

Command screenshot :

Remove image

podman rmi imagename

Command screenshot :

Show Podman process status

podman ps -a

Rest of the support commands is shown as below :

If you use docker-compose , there is an alternative for this podman-compose.

Note : Natively docker-compose is yet not supported by Podman yet at the time of my testing of Podman Release v4.0.0 version. And the one available is very unreliable.

The setup is straightforward. Install Python if you dont already have it, and then podman-compose.

brew install python@3.10pip3 install podman-compose

Podman in conjunction with podman-compose works well.

Ive had trouble getting podman-compose over Mac because there isnt an official document for installation other than the one mentioned above.

Conclusion 💁🏻

Podman wraps around Dockers capabilities to provide a lightweight container runtime that can be used in Daemonless and Rootless modes.

Limitations of Podman 🥲

Linux based.
No support for Windows OS based Containers. (Supported now with the help of WSL)
Docker-Compose component is still non-reliant
No GUI unlike Docker Desktop, Rancher Desktop.
New product with bugs and still coming features.
No Docker Swarm.

That being said, Podman is still a new technology that is improving, and it may be best to wait and see until we see community acceptance of Podman and it becomes a more developed and reliable tool.

You can certainly experiment with it on your local workstations and learn more about it, but bringing it into your production system may take some time.

Please share your opinions about Podman and this topic in the comments section.