I can only provide my experience; it was a drop-in replacement. I have 7 services running and 3 db containers. I was able to migrate using the Podman official instructions without issue.

from what I can gather its currently recommended to use quadlets to generate systemd units to achieve what compose was doing. podman compose is a thing but IIRC I didn't find that was straight drop in and I had to change the syntax or formatting a bit for it to work and from the brief testing I have put in quadlets seems less hassle, but if you use a non systemd distro then I don't know.

I'd say about 99% is the same.

Two notable things that were different were:

• Podman config file is different which I needed to edit where containers are stored since I have a dedicated location I want to use
• The preferred method for running Nvidia GPUs in containers is CDI, which imo is much more concise than Docker's Nvidia GPU device setup.

The second one is also documented on the CUDA Container Toolkit site, and very easy to edit a compose file to use CDI instead.

There's also some small differences here and there like podman asking for a preferred remote source instead of defaulting to dockerhub.