> but instead to create a bespoke mechanism involving a bunch of tiny files, all of which is insanely system (linux) specific, and therefore completely non-portable.

To nit pick slightly, it's not really a bespoke mechanism it's just re-using the mechanisms provided by systemd. Quadlets are implemented as a systemd generator in order to re-use the existing service management system that exists on essentially all major Linux distros. Quadlets are less a direct competitor with compose (hence why Podman implements the compose spec) and more a way to better integrate containers with the rest of a system. The closer Podman native equivalent to compose is Kube files.

FWIW, for me docker compose works just fine with podman. I am not sure what kind of additional configuration is needed these days, make sure you are running podman with the socket thing and perhaps set DOCKER_HOST. It's just a client / frontend to an API that podman provides.

Depends on your point of view.

It can be argued that it’s Docker that is reinventing the wheel and doing its own bespoke process management, journal management etc when all of these are solved problems on Linux. Podman is instead reusing the platform which exists, Quadlets are just reusing systemd, so as a sysadmin I can manage, control and monitor docker containers using the same standard tooling that I already use to manage, control and monitor all the other processes which are running on the system.

Architecturally I find the above argument attractive. The problem is chronology. Docker and docker compose came before systems was ubiquitous and long before Quadlets, so it’s natural to think of Quadlets as reinventing the wheel.

Personally I wish docker had not rejected composition/integration around systemd. Would have made everyone’s job a lot easier in the long term.

Quadlets are awesome and honestly I think one of the best additive things that podman has on top of the regular docker toolset.

I use podman regularly, and despite it being a good drop-in replacement like 95% of the time, the 5% of the time where it isn't seamless are super painful. For example, skaffold (https://skaffold.dev/) pukes all over itself when you try to run podman as a drop in replacement. I'm sure there are plenty of other examples, but that one stops me from using podman at work in addition to in my personal projects.

Well, but that's kinda the point, isn't it? You know that other mechanisms are possible, but you opted out for a user systemd file. I know that too, and I also just use systemd for that. Because the alternative doesn't look much easier. I guess it makes sense that they try to discourage it now, because for serious deployment it isn't the best option. But when I install Podman on my laptop, I really wish the systemd configs would be added automatically without me even knowing.

I mean, really, if we keep in mind that formally these are 2 totally unrelated projects, it's hard to complain. Yes, it's almost seamless. But since when installing Podman everyone thinks roughly "I am installing a newer better Docker version", and we all already have a few dozens of custom Docker containers running, it's hard no to wish it was even more seamless and backwards-compatible. I remember the transition process wasn't nearly as smooth as I hoped, and every small glitch is kinda stressful, because you know that currently all of it "somehow works", and if something breaks you probably won't even notice right away.

Linux. It’s not the installation of podman that can be fiddly. It’s the setting up systemd unit files and local user accounts for rootless / daemonless deployment of containerized apps that can be a headache.

It’s not hard. It’s just fiddly.

Or, to look at it another way, the answer is that it’s the developers who don’t want to learn something new that, objectively speaking, might turn out to be better than what they’re used to.