> Docker actually has more infrastructure requirements than alternatives.

I was mostly comparing Docker to system packages, and I was specifically thinking about how trivial it is to use Docker Hub or GitHub for image hosting. Yeah, it's "infrastructure", but it's perfectly fine to click that into existence until you get to some scale. I would rather do that than operate a debian package server. Agreed that Nix works pretty well for that case, and that it has other (significant) downsides. I'm spiritually aligned with Nix, but Docker has repeatedly proven itself more practical for me.

> Definitely depends on the codebase, but sure, packaging usually involves adhering to some kind of discipline and conventions whereas Docker lets you splat files onto a disk image via any manual hack that strikes your fancy. But if you don't care about your OCI images being shit, you might likewise not care about your DEB packages being shit. If that's the case, you can often shit out a DEB file via something like fpm with very little effort.

I'm not really talking about "splatting files via manual hack", I'm talking about building clean, minimal images with a somewhat sane build tool. And to be clear, I really don't like Docker as a build tool, it's just far less bad than building system packages.

> don't really understand this preference; I guess we just disagree here. Systemd has been around for like a decade and a half now, and ubiquitous for most of that time.

Yeah, I don't dispute that systemd has been around and been ubiquitous. I mostly think it's user interface is hot garbage. Yes, it's well documented that you can get rid of the pager with `--no-pager` and you can put the logs in a sane order with `--reverse` and that you specify the unit you want to look up with `--unit`, but it's fucking stupid that you have to look that stuff up in the man pages at all never mind type it every time (or at least maintain aliases on every system you operate) when it could just do the right thing by default. And that's just one small example, everything about systemd is a fractal of bad design, including the unit file format, the daemon-reload step, the magical naming conventions for automatic host mounts, the confusing and largely unnecessary way dependencies are expressed, etc ad infinitum.

> Why would I want a separate, additional interface for managing services and logs when the systemd stuff is something I already have to know to administer the system anyway?

I mean, first of all I'm talking about my preferences, I'm not trying to convince you that you should change, so if you know and like systemd and you don't know Docker, that's fine. And moreover, I hate that I have to choose between "an additional layer" and "a sane user interface", but having tried both I've begrudgingly found the additional layer to be the much less hostile choice.

> I also frequently use systemd features that Docker just doesn't have, like automatic filesystem mounts (it can do some things fstab can't), socket activation, user services, timers

Yeah, I agree that Docker can't do those things. I'm not even sure I want it to do those things. I'm talking pretty specifically about managing my application processes. But yeah, since you mention it, fstab is another technology that has been around for a long time, is ubiquitous, and is still wildly, unnecessarily hostile to users (it can't even do obvious things like automounting a USB device when it's plugged in).

> ... dependency relations between units, descri ing how services that should only come up after the network is up, etc. Docker's tooling really doesn't seem better to me.

Docker supports dependency relations between services pretty well, via its Compose functionality. You specify what services you want to run, how to test their health, and how they depend on each other. You can have Docker restart them if they die so it doesn't really matter if they come up before the network (but I've also never had a problem with Docker starting anything before the network comes up)--it will just retry until the network is ready.

Docker's tooling is better in its design, not necessarily a more expansive featureset. It has sane defaults, so if you do `docker logs <container>` you get the logs for the container without a pager and sorted properly--you don't need to remember to invoke `sudo` or anything like that assuming you've followed the installation instructions. Similarly, the Compose file format is much nicer to work with than editing systemd units--I'm not huge fan of YAML, but it's much better than the INI format for the kind of complex data structures required by the domain. It also doesn't scatter configs across a bunch of different files, it doesn't require a daemon-reload step, the files aren't owned by root by default, they're not buried in an /etc/systemd/system/foo/bar/baz tree by default, etc.

Like I said, I don't think Docker is perfect, and I have plenty of criticism for it, but it's far more productive than dealing with systemd in my experience.