Honestly I reach for podman or `nix develop` any chance I get. What is the edge that docker provides these days?

▲ jillesvangurp 3 hours ago | parent | next [-]

> What is the edge that docker provides these days?

hub.docker.com mainly, the centralized docker registry. A bit like Github, there are plenty of alternatives. But that's where you find most people pushing their containers.

And then there is Docker Desktop which a lot of users seem to like.

I switched to colima myself recently (on a mac). I think people overthink all this stuff a bit. Colima doesn't have a UI; but that's fine for me. I mainly use it to run stuff from the command line or from scripts. I wasn't using the Docker Desktop UI very much either.

Colima is a simple wrapper around Lima, which is a simple wrapper around qemu or Apple's virtualization layer. The resulting vm runs a simple Linux distribution with some file mounts and network tunneling to give you a similar experience as Docker Desktop. Which does exactly the same thing in the end of course.

Linux runs containers just fine. The main thing you need for containerization is a Linux kernel. People have actually hacked together docker alternatives with just bash and namespaces. I used a plain qemu vm for a while with the docker socket pointing to an ssh tunnel on my mac. Works amazingly well but it has some limitations. Colima is easier to manage.

People have mentioned several of the other alternatives already. They all can work with the same command line tooling. If you need a UI, colima is probably too barebones. But otherwise, things like IDEs and other tools work (e.g. lazydocker, vs code, intellij, etc.) just fine with it. So the added value of extra UI is limited to me at least.

I think the container runtime inside the vm (podman, containerd, whatever) is mostly not that relevant for developers. It's a bit of an implementation detail. As long as docker and docker compose work on the command line, I'm happy.

▲ szszrk 7 hours ago | parent | prev | next [-]

How do you manage your containers in podman declaratively?

I tried to substitute docker-compose with Podman and Quadlets on a test server the other day, but was shocked how badly described the overall concept is. Most materials I found glimpsed through ability to run it as root/user and how different that is in configuration, and repeated the same 4-6 commands mantra.

Spent a few hours on it and just... failed to run a single container. systemctl never noticed my qualdet definitions, even if podman considered my .container file registered.

A bit.. frustrating, I expected smoother sailing.

▲ Fabricio20 4 hours ago | parent | next [-]

This has also been my experience, I'm used to using compose everywhere. I like the declarative file - tried podman and I found the documentation around the concept so scarce and all related to running things as non-root instead of telling me how my docker-compose becomes podman-compose. Still using docker everywhere because of that. Docker swarm mode has also worked wonders as an evolution to my compose files.

	▲	szszrk 3 hours ago \| parent [-]
		I know podman-compose, have some homelab services running on it for a few years, but honestly found multiple ones that failed. It's far from drop-in replacement.

▲ jabl 7 hours ago | parent | prev | next [-]

The podman kube support? It provides similar functionality as docker-compose, using a yaml file which is a subset of the Kubernetes pod definition syntax.

Then you can just create a few line systemd unit definition, and it integrates as a normal systemd unit, with logs visible via journalctl etc.

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unitexe 5 hours ago | parent [-]

This seems to be the way.

Short of weeding through the docs, I found the "Play with Kube using Podman" talk on DevConfs YouTube channel helpful.

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szszrk 3 hours ago | parent [-]

I will be honest: that is even more confusing :)

> Note: The kube commands in podman focus on simplifying the process of moving containers from podman to a Kubernetes environment and from a Kubernetes environment back to podman.

I'll give it a try, but I'm starting to understand why there is so little use of podman among amateurs.

	▲	unitexe 3 hours ago \| parent [-]
		Personally, I am not interested in kubernetes, just podman for single-node use case. What the kube YAML does for this use case is provide a way to declare a multi-container application. The podman documentation pages I have found most helpful for this use case are podman-kube-generate (generate kube YAML from an already running pod), podman-kube-play (run the kube manually) and podman-systemd.unit (run the kube as a service). Edit: I should also mention that there are pod units (which don't require the use of kube YAML) but I skipped over them because they do not support podmans auto-update feature.

▲ supernes 7 hours ago | parent | prev | next [-]

Podman supports Compose files, so there's that. I've only glimpsed at Quadlets and I agree they seem very esoteric, especially if you're not very well versed in systemd service definitions.

▲ bootsmann 7 hours ago | parent | prev | next [-]

Yeah I think Quadlet just has bad docs. They document the whole API but iirc there is no: ok this is the hello world for running cowsay as a systemd unit

▲ exceptione 7 hours ago | parent | prev [-]

quadlets fully depend on systemd doing its work. So, assuming you are running rootless, if you change your quadlets, you will need

  systemctl --user daemon-reload

to let systemd ingest the changes. And, if you have configured to start your container on boot, then still you have to start the container by hand, as you typically won't reboot during development. If you have multiple containers, it might be easiest to have them in one pod, so you only need to start the pod.

I agree that the documentation needs a good tutorial to show the complete concept as a starting point. There are multiple ones though on the internet.

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szszrk 3 hours ago | parent [-]

yeah, that's exactly what every tutorial says. And I know systemd more or less, daemon-reload is no stranger to me.

That was not sufficient. Both for global o user setup.

	▲	stryan an hour ago \| parent [-]
		The biggest problem with the `systemctl daemon-reload (--user)` workflow to register quadlets with systemd is it hides any generation errors in journald instead of giving immediate feedback. It's a real pain in the ass, and I say this from a place of love. Quadlets are just a systemd generator: all `daemon-reload` is doing is running `podman-system-generator` which looks at the Quadlet files and turns them into systemd unit files with a big honking `podman run --rm --blah container:tag` as the `ExecStart` property. There's nothing else to it, no daemons or what not If you ever feel like bothering to give it another shot check journalctl to see if there's any generator errors. Or run the generator directly: on my OpenSUSE box it's at `/usr/lib/systemd/system-generators/podman-system-generator` , Run it with `--dry-run` to just output to stdout and `--user` to get user quadlets.

▲ b40d-48b2-979e 8 hours ago | parent | prev | next [-]

    What is the edge that docker provides these days?

Enterprise support and Docker Desktop makes it nearly seamless to get set up using containers. I've tried Rancher/podman/buildah and the experience introduced too much friction for me without being on a Linux system.

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troyvit 7 hours ago | parent | next [-]

> [...] without being on a Linux system.

I'll add that needing to be on the "right" Linux system is another strike against Podman. Last I checked if I wasn't on a RedHat derivative I was in the wilderness.

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travisgriggs 6 hours ago | parent [-]

Huh. I tried docker. Didn’t like the odor of enshittification, and so switched to podman (desktop). I use it on macOS, and deploy on Ubuntu. It’s been smooth sailing.

I found the signal to noise ratio better in Podland. As a newb to docker space, I was overwhelmed with should I swarm, should I compose, what’s this register my thing? And people are freaking about root stuff. I’m sure I still only use and understand about 10% of the pod(man) space, buts way better than how I felt in the docker space.

I miss when software engineering put a high value on simplicity.

	▲	troyvit 5 hours ago \| parent [-]
		Yeah I was pretty hard on podman in that comment but the truth is I use it over docker wherever I can. I have a mixed environment at home but settled on RedHat for the home server and everything seems totally ok. I really like quadlets, and the ability to go rootless is a big load off my mind to be honest. I do wish they'd package it for other distros though. It would save some headaches.

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koe123 8 hours ago | parent | prev [-]

Fair! I haven’t done any container related activities on Windows.

▲ pzmarzly 7 hours ago | parent | prev | next [-]

Docker, or rather containerd, still has better plugin ecosystem around it. Unregistry https://github.com/psviderski/unregistry, Nydus https://github.com/dragonflyoss/nydus, all the different "snapshotters" (storage formats), or the utils for sharing NVIDIA GPUs with containers, etc.

The gap with Podman is closing though, and most users don't need any of these in the first place.

▲ darkwater 8 hours ago | parent | prev [-]

> What is the edge that docker provides these days?

That you are not the average developer

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swores 8 hours ago | parent [-]

Not very clear what you mean... well you haven't actually given them an answer to their question.

Are you suggesting that docker provides an (unspecified) edge to developers who are better than average? Or to those who are mediocre? Or...

	▲	darkwater 7 hours ago \| parent [-]
		I mean that the average developer will follow/use what has the most traction already and in the containers space, like it or not, it's still Docker.