Comment by c-hendricks 3 days ago
So for my set of DVR services, quadlets would have me replace a single compose.yml with 6 .container files, and manually create the network, and have to stop and start all of the services individually.
Not sure I'm sold.
How would I share Quadlet files for my repo? Today I have a docker-compose.yml in my repo, the instructions to try it out are usually `docker compose up --build -d`.
I read about the recently released CLI support for quadlets [0] and the ability to install Quadlets from a URL but still cannot wrap my head around it (as in, no matter how I look at it, Quadlets seem to require non-trivially higher knowledge to use and more steps/files).
If we need a concrete example to discuss: https://github.com/oslc-op/refimpl/blob/main/src/docker-comp...
[0]: https://blog.podman.io/2025/08/level-up-your-container-game-...
Quadlet is only for managing containers. If you need to build images too, you need to use the "buildah" CLI tool. If you know what a systemd service file is, a quadlet is essentially just that. It's a service file that automatically handles the annoying details of creating a systemd service to start/stop your container properly.
But Quadlet needs a container image before it can create a container. The example compose file you linked includes steps for building Dockerfiles. Quadlet doesn't do that. Instead, you'll need to do it as a separate step using buildah (https://www.redhat.com/en/topics/containers/what-is-buildah)
Compose does a lot of stuff, so migrating away from it isn't always easy. In this case, you'd probably need to bring in a build system like Make or some custom scripts to build all the container images you need. Once you rebuild an image, you can restart your quadlet-managed containers with `systemctl restart my-container` and they'll automatically use the new image.
I don't do much web development these days, so I'm definitely not an authority on container-based development workflows. Maybe there are better tools out there, or maybe compose is still the best tool for that job. But quadlets are definitely the better choice when it comes to deploying/orchestrating your containers without getting into a full blown kubernetes setup.
Quadlet supports ".build" and ".image" files, and ".container"s can have an auto-update policy (supported by manually invoking `podman auto-update` or the daily timer.)
It sounds interesting, but with some caveats / things that require other tooling, maybe migrating all my services from compose to quadlets would end up a fairly lateral move.
Quadlets also support a .kube file. I have a similar use case where I have 6 containers I want to all run on the same network. So have a k8s YAML file that has a pod with the containers, their configuration and path mapping and then a have a `service.kube` file with a '[Kube]' section and a 'Yaml=/path/to/config.yaml' directive. That creates a single service to stop/start with systemd and has all the containers running on the same network in a single pod.
Not sure what your compose file looks like, but my container files are tiny, flat, and trivial to maintain.
> manually create the network
There's no way for me to know what your requirements are, but often times if you just need your containers to talk to each other, all you need is an empty file with a unique name. So `touch MyDVRNetwork.network` to create it, and add `Network=MyDVRNetwork` to your containerfiles.
> and have to stop and start all of the services individually.
Nope, container files are essentially already systemd service files. If you add them to the correct folder and set up the dependencies, systemd will automatically start them in the correct order at boot time, restart them if they fail, etc. That's the best part of quadlet IMO. Literally set it and forget it, and the process works the same for rootless containers (you just need to add them to your user folder instead of the system-wide folder)
It gets even more awesome when you combine them with something like Fedora CoreOS and Butane. With a few small text files, you can declaratively generate an OS image with all of your desired services ready to go. It is pure bliss.