Linux

Part of the purpose of NixOS is providing a means to build a reproducible environment that's easy to configure, migrate, and rollout. You can absolutely handle configuration of many different programs using either flakes or the native modules provided by nix. You can customize your entire system from firewall entries, to users and their shells, to the kernel itself and the kernel modules you'd want it to load, all in a single file or multiple files. If you want to try doing all those things in bash scripts, good luck and please share your experiences but don't expect it to be as easy as the Nix ecosystem.

There is a world of difference between a bash script and something like NixOS. The most important difference is that with NixOS something that you don't specify won't be there. Whereas a bash script (or other config management tools like Puppet, Chef or Ansible) only mutate things listed.

So it is very easy to write a script like:

ensure_installed python3
write_file /etc/foo.cfg 'thing = 7'
chgrp users /mnt/backups

But if you remove ensure_installed python3 it will stay installed. You can try to be very careful and always add ensure_not_installed python3 but this is both error prone and dead code as soon as you run it. I used to have a script like this and I used each of configuration management tools mentioned above and always ran into these issues. The exact error flow would be something like this:

1. Enable/setup some service A that pulls in package X.
2. Disable service A or remove package X because it isn't needed anymore.
3. Write configuration for service B.
4. Forget to add ensure_installed X but it works anyways because X is still installed from step 1.

Now you have a non-reproducible config because if you try to re-install or setup service B on a new machine it won't work because X isn't present. This may sound like a niche problem but I ran into it almost every time I tried to bring up a new machine using my config.

It is still possible to do this in NixOS as it isn't completely reproducible (you can have mutable state) but in general it is much harder because any configuration that isn't specified doesn't exist. As soon as you remove package X or service Y from your config it is removed from your system. I've been using NixOS for 8 years now and this problem is mostly gone. It is definitely more reproducible than bash scripts and it has a tangible effect on my workflow.

I wrote a blog post about it a long time ago but the core is still relevant: https://kevincox.ca/2015/12/21/service-management-with-nixos/.

It's true that it can be a powerful distro but I've also heard from some users that the advanced-level documentation is lacking and only limited to forums and source code. I think maybe if the documentation was more thorough I would try nixos.

you have to have a lot of linux/programming knowledge to do even the simplest things like installing/updating your software

So, pretty much like any other distro

Its getting better which each release

Thanks for this, it was definitely a nice overview. Not the first time I'd heard of NixOS, but I do seem to be seeing more frequent and more substantial discussions of it.

What I'm getting from all this, is that it looks to be a great way to set up reproducible desktop environments. And servers too, I suppose.

What I'm not getting from this: a compelling reason to switch from established players like RHEL and Ubuntu in combination with cloud-init and Terraform and the likes of Chef/Puppet/Ansible/Salt to spin up a cluster in the cloud, reconfigure, tear down, etc.

In case anyone is misreading me: this is not a dig at NixOS. It definitely looks interesting. Like, to the point that I'll at least spin up a VM on my Manjaro laptop and see whether I should perhaps consider wiping and reinstalling with NixOS. The "configuration through code" is extremely appealing here.

My concern here is corporate inertia. And before anyone gets gets ready to launch a diatribe about how corporations don't decide what the best tech is, I will agree with you. I've been around a while, and excitedly watched as Unix ramped up and displaced platforms like VAX/VMS and AOS/VS, using smaller and faster hardware. Then along came Linux and the battle for which distros would dominate.

As for configuration through code, I've been keeping a keen eye on things (tinkering when it's been possible to do so) since the days of cfengine and Jumpstart. I used to share this site with anyone that would listen to me; it's dated now, but the underlying principles are (were?) solid: http://infrastructures.org/

So for now, I think I'll have to limit my professional NixOS usage to tinkering and potentially useful side projects. For personal usage? Yeah, it might become my daily driver, but I need to find the time to tinker.

I will say that I'm presently involved in an effort to test something out that has my company's product available using rpm-tree. Not my decision, this is all being driven by a customer that has a lot of clout; they really, really want to use rpm-tree. It's proven to be a bit onerous at times.

What this NixOS discussion has managed to do for me is to have me wondering whether a NixOS approach would have worked out better; my sense is that yeah, maybe it would have. But my feelings here might simply be the result of "woo, shiny new object", which has definitely colored my opinions of things in my career of ~35 years. Something that I've had to restrain my excitement over, pending corporate sanity checks.

Having the option to have multiple versions of a dependency without needing to have duplicates of the same version alá flatpak seems like it should've been a no-brainer on any linux distro.
With that said I'm very comfortable with my current system, so definitely not until I get majorly fucked by my life-choices
Definitely sounds like a competent player in comparison to most distros though.

And I feel like the terminal isn't as big a barrier as everyone makes it out to be (part of why I say that is because I think the entire concept of "beginner friendly distros" only makes the terminal seem more impenetrable through that wording)

All-in-one config is definitely something I would've hoped Arch had as well, and as a bonus I would love a system that kept all things related to the user in /home (I'm not completely sure Nix does but I may as well throw that in) (homed does not do that as it still has entities outside of /home that you better back up, in fact you'll risk being locked out of your user if you don't)