> The exam is online, using Google Chrome browser on Windows or MacOS ONLY.
  > Linux support IS NOT available at this time;

I had to read to whole thing twice to convince myself that it wasn't a joke.

BTW, I don't understand why there's a need for Docker certification in the first place.

Because they have to make money somehow. They took $300M in VC funding. Their product is open source and was subsumed by Kubernetes.

And podman seems to be better than docker in every respect, and it doesn't require special permissions.

I'm not an expert in this area. Are there any things docker does that podman cannot? Also how much code do do they share? (as in libraries used by both)

There is podman-compose as a drop-in ( https://github.com/containers/podman-compose ), but last i checked it wasn't supported by or developed by RedHat themselves, hence no first-party support. In addition to that, the feature parity just isn't there.

Also, there is no docker.sock, which tools like Portainer ( https://www.portainer.io/ ) need to interface with Docker, hence no control web apps and other tools are available for Podman.

Besides that, there is also Docker Swarm ( https://docs.docker.com/engine/swarm/ ), a lightweight orchestrator which can be a simpler alternative to Kubernetes in smaller and more resource constrained environments, which isn't available in Podman. In addition to that, Docker Swarm's deployment format is also extremely similar to the Docker Compose one (with additional functionality added for multi node clusters), which allowed for getting started with container orchestration in a more simple fashion.

If you're in a Kubernetes shop and simply need something for Kubernetes to interface with, then containerd (which Docker uses internally) and Podman are largely comparable.

In other circumstances, Podman doesn't have complete feature parity with Docker, despite popular claims and despite its architectural improvements.