My experience with NixOS

https://blog.patchgirl.io/nixos/2020/03/31/nixos.html

by matsutsu • 6 years ago

289 92 6 years ago

blog.patchgirl.io

dragonsh3• 6 years ago

NixOS is good, if you found not enough documentation, try Guix and may be GuixSD. It uses guile (scheme) and has fantastic documentation. [1]

Earlier Nix had additional NixOps but that too now is available with Guix deploy. I am waiting when I can run Guix within a lxd container, shepherd init still has some rough edges with LXD container init.

Both are great piece of software and a new take on building OS and distribution. They are ahead of their time might take another 4-5 years before they become more mainstream.

[1] https://guix.gnu.org/help/

eadmund• 6 years ago

How is Shepherd broken with LXC?

Is it sufficient to run Guix atop another distribution, or run Guix SD in a qemu VM?

dragonsh3• 6 years ago

GuixSD does not work without making changes within a LXD container (not VM). One of the details on how to do it is in mailing list. [1]

[1] https://lists.gnu.org/archive/html/help-guix/2018-10/msg0006...

throwaway8943454• 6 years ago

Our organization tried Nix for many years. Most of our problems were around usability, lack of documentation (including zero docstrings or type annotations in nixpkgs), and the overt unfamiliarity of the Nix expression language (asking a whole organization to learn something that seems deliberately cryptic isn't a recipe for success), and a long tail of other things. Still, at its core Nix for package management seems like the future; I just have no confidence that they're going to iron out those issues in the next 4-5 years.

Of course, none of that speaks to Guix as I haven't used it, but hopefully it's awesome and solves all of those problems.

lidHanteyk2• 6 years ago

To me, this is a success story; your organization wasn't sufficiently flexible to adopt new technologies which require rethinking the fundamentals of package management. Take this as a warning sign and re-orient your organization.

I do wonder about the "deliberately cryptic" nature of Nix's expression language. It is, in fact, deliberately designed for simplicity, to be a basic syntax for a language that is purely functional and lazy but not much else ([0] p69). When folks complain about the Nix expression language, as they often do, I ask them: What would you change? How would you do it?

I think that it is bad that an entire team does not have the bandwidth to learn an entirely new language, but good that the team is not willing to spend time on things which they don't think are important.

[0] https://edolstra.github.io/pubs/phd-thesis.pdf

arianvanp3• 6 years ago

My problem with Nix was not the language, but the very confusing CLI and the way updates were done (nix-channel) and the difficulty of pinning dependencies or documenting how to do that. However, they have been hard at work at a nix CLI 2.0 which is much better, and a new uddating mechanism that is way easier to understand: https://github.com/NixOS/rfcs/pull/49

This gives me hope things are getting better.

Also recently I funded a project for improving error messages in Nix https://opencollective.com/nix-errors-enhancement

Ther is also now a dedicated Nix Marketing team which are working on improving the website and the documentation

zymhan• 6 years ago

I worked at the company that "started" Nix, and I can assure you that we had those same issues internally, even when the whole Nix dev team was on our payroll.

rauhl• 6 years ago

Guix looks really cool. I wish that it used Lisp rather than Scheme (because IMNSHO Lisp is better-suited to this kind of system software), but that ship has sailed.

It’s a real shame that rms had such a dislike of Common Lisp. The mind boggles at where the cutting edge of computing would be today had Emacs upgraded from Elisp to Common Lisp twenty or thirty years ago. Instead GNU has spent 27 years trying to turn Scheme into a sufficient systems programming language, once again illustrating the truth of Greenspun’s Tenth Law: Any sufficiently complicated C or Fortran program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp. I would add a corollary: this also applies to any sufficiently complicated Scheme program.

flavio81• 6 years ago

RMS dislike of CL was purely due to personal factors: He felt cheated by the Lisp machine industry.

kalium-xyz2• 6 years ago

I don't see why you say that NixOS does not have enough documentation, a commonly cited problem is the lack of tooling rather than the lack of documentation which would be fair. NixOS has the most extensive documentation out there for any linux distribution which I've used [0] and each package is documented and contains the information of any option it offers from the nix code itself and the tooling [1].

Furthermore I do not think you can compare Guix to Nix for commercial work as Nix is LGPL [2] with the packages being MIT [3] where Guix is GPL [4] allowing for Nix derivative work to be used commercially with little restriction.

I wish Guix had stayed as a guile layer for Nix and not gone off in its own direction because of the licensing ambiguity (as far as I can tell this is the reason) in Nix packages. If anyone has more insight on why this split happened or the possibility of making such layers for Nix I'm very interested in this topic.

[0] https://nixos.org/learn.html [1] https://nixos.org/nixos/packages.html?channel=nixos-19.09 [2] https://github.com/NixOS/nix#license [3] https://github.com/NixOS/nixpkgs/blob/master/COPYING [4] https://guix.gnu.org/about/

dragonsh3• 6 years ago

In the blog post if you read the person complained about it, so said can give a try to Guix. I think both Nix and Guix are good, personally I like Guix being familiar with lisp and scheme feels very natural to work with Guix, with Nix need to learn new declarative syntax.

Linux kernel itself is GPL, so not sure what’s the issue with Guix. Obviously Guix package repository only support libre software, but if you need to use proprietary repository try Guix-nonfree[1].

I am happy Guix and GuixSD exist. Check the gnu Guix mailing list archive both have same roots but are sufficiently different[2].

[1] https://github.com/guix-users/guix-nonfree

[2] https://lists.gnu.org/archive/html/guix-devel/2019-09/msg002...

mbakke2• 6 years ago

GNU Guix 1.1.0 was released just hours ago, so now is a good time to try it: https://news.ycombinator.com/item?id=22877788 :-)

Rumor has it that Guix will be included in a future Debian release too. It is already available in Arch, Gentoo, and OpenSUSE.

rudolph93• 6 years ago

It’s really great that functional package managers are getting all this attention! Nix package manager can run on Arch and Gentoo and OpenSUSE also.

downerending3• 6 years ago

I recently read that Guix was dropping support for the Linux kernel, but apparently that was a Apr 1 joke. Argh.

https://guix.gnu.org/blog/2020/deprecating-support-for-the-l...

haolez2• 6 years ago

Forgive me for using buzzwords, but what's the "cloud native" story on NixOS? Can I easily create containers and update my orchestrator's deployment? Can I abstract things like AWS Lambdas into this immutable build structure?

bennofs• 6 years ago

You can build docker images with Nix (https://nixos.org/nixpkgs/manual/#sec-pkgs-dockerTools), but right now it wouldn't make much sense to use the NixOS modules (like nginx) for that. The modules in NixOS assume a systemd based environment and are thus not suitable for use in containers (in the end, most service modules generated systemd units).

What you can do, though, is use Nix to build a container image with an nginx config. You just can't use the abstractions present in NixOS as-is to generate the nginx config, you'd have to write the nginx config yourself (just as you would if you use a Dockerfile). You could perhaps re-use parts, or modify the NixOS modules, though.

slobotron• 6 years ago

We are using Continix[0] to package up regular NixOS modules in docker

[0] https://github.com/notgne2/continix

jarvuschris• 6 years ago

Chef Habitat might be more what you're looking for in that regard, it very much feels like an intellectual derivative of NixOS and focuses on the cloud native story

wyager• 6 years ago

Not having used it, maybe NixOps is the thing you want.

haolez2• 6 years ago

I think it's more geared towards creating VM instances. I'm thinking about other resources as well, such as Lambdas.

arianvanp3• 6 years ago

I would say Nix's cloud native story is "best in class".

you can take any nixos configuration and turn it into a cloud image https://github.com/nix-community/nixos-generators

You can take any nix package and turn it into a docker image https://news.ycombinator.com/item?id=20720922 https://news.ycombinator.com/item?id=18111954

You can even use Nix to create and deploy cloud resources ala Terraform:

github.com/nixos/nixops

Some other notable uses of Nix in cloud native landscape:

https://github.com/saschagrunert/kubernix - a KIND alternative

https://github.com/xtruder/kubenix a Nix DSL for defining and deploying entire kubernetes clusters + deployments (combines nix's docker image building support and deployment support for and end to end cloud-native solution)

I personally think Nix should heavily market itself to the CLoud Native buzzword hype train. as it's my favourite weapon in this space

kalium-xyz2• 6 years ago

I switched to using Pulumi from NixOps because of the lack of tooling in the Nix ecosystem (also NixOps is frequently broken in all sorts of ways due to not having as large a community). Is there some ideal way to work with it to get it to behave without having to make your own tooling or would you consider my approach to instead create support for Nix in Pulumi (which I have not done as of yet but there are terraform packages so I'm hopeful on the feasibility of this project)?

ghuntley3• 6 years ago

https://grahamc.com/blog/nix-and-layered-docker-images

golergka2• 6 years ago

I'm yet to see a backend app architecture that both is elegant and effective from developer perspective and at the same time doesn't push her to make unneccessary database calls for each request when business logic becomes significantly complex.

yjftsjthsd-h2• 6 years ago

doesn't push her to make unneccessary database calls for each request when business logic becomes significantly complex.

Are you objecting to holding all state in a database, or something else? If so, the only real alternative is to have individual servers hold state, which seems like a poor choice; one way or another you're going to hit the CAP theorem, and databases are well-optimized for getting you the best results from CAP that you're going to.

golergka2• 6 years ago

Absolutely not. On the contrary, I'm one of those developers who prefer to do things in SQL rather than application logic.

Zinggi• 6 years ago

You might be interested in lamdera. It abstracts away database access, data transport and data encoding between client end server. Here is a talk about it: https://www.youtube.com/watch?v=nSrucNcwlA8

If you're interested, you can probably get an invite from @supermario on the elm slack, or on: https://lamdera.app/

Disclaimer: I'm not affiliated with the project, but I've met Mario in person and he's a cool dude with great ideas ;)

gt565k2• 6 years ago

We used their build system Hydra at a previous company and all of our deployments were on NixOS.

Check this video out from Rob Vermaas. It's a decent case study of how Nix was applied at LogicBlox

https://www.youtube.com/watch?v=nuyuA43q9NE

exdsq• 6 years ago

I moved to NixOS the other week and love it. Being able to play about and roll back to previous configurations is honestly amazing once you get into a position that you need it. I tinker with my OS and this happens more often than I’d care to admit!

Nix as a build tool is also quite nice, but honestly NixOS is the main attraction for me.

rudolph93• 6 years ago

I recently switched to NixOS and have essentially configured my OS from scratch in less than a week and now use it as my main system.

The thing to remember about NixOS is it’s not a distribution of KDE or Gnome or manager of anything, it’s a declarative way of configuring those things and allows you to easily roll back changes to entire OS.

It’s a little bit of investment to get started but one you get rolling it’s such a breath of fresh air to be able to manipulate your whole OS in the similar pragmatic way to you iterate code in a git repo.

darau1• 6 years ago

manipulate your whole OS in the similar pragmatic way to you iterate code in a git repo

I've been trying to do this for ages with a dotfiles repo and some git aliasing. I really want to try it out, though. Any gotchas or hidden pitfalls I should look out for?

mbakke2• 6 years ago

One common beginner mistake is attempting to modify files in the immutable store directly. Don't do that. The system is read only for a reason.

Also make sure you allocate enough space on your root partition so you don't have to run garbage collection all the time.

Shoue3• 6 years ago

My tip: don't use nix-env to install packages like it's Aptitude or Pacman, use `nix run` if you need a package temporarily, home-manager if you need a user-level package permanently, or just straight up change the configuration.nix to include the package as a system-wide one.

If you use nix-env you're just polluting your environment in an imperative way and that is pretty much going against Nix' declarative nature.

downerending3• 6 years ago

I recently switched to NixOS and have essentially configured my OS from scratch in less than a week

That doesn't exactly scream ease of use.

bamboozled• 6 years ago

You can get up and running in probably a day (you need to learn a few things), I'm guessing what they mean is, configured exactly how they want.

I had a similar experience with NixOS and I love it.

chongli• 6 years ago

NixOS isn’t easy to use. It’s very powerful though. It gives you the ability to configure your whole OS, including all of your packages and configurations, in one declarative file. It reproduces the entire installation from this file in a way that’s fully immutable and hash-perfect (with minimal building from source). Very cool.

DethNinja• 6 years ago

Could someone summarise what is the advantage of NixOS compared to something like Ansible or Saltstack + any other Linux distribution?

tbenst• 6 years ago

I used a Ansible for years before switching to NixOS. The problem with ansible is it is an imperative configuration tool that makes efforts to be declarative, but is not fully. Most runs fail to be declarative, eg even something as basic as “apt update” is irreversible. Ultimately, Ansible requires you to write code that is (State, Code) -> New State, whereas NixOS is truly Code -> State

jordanbeiber• 6 years ago

NixPkgs amongst other things replace rpm/deb packages - and having a package install declared in a git repo is awesome compared to installing a pre-packaged compressed blob.

Nixos keeps the entire system state based on a declaration and lets you move back/forward on whole system configurations super quick.

Ansible and salt does not really declare a complete system state but rather try to manipulate the underlying system. Ansible keeps no state at all actually.

Nixos+pkg is all about declaring and keeping a state of a machine as much as reasonably possible. It has it’s flaws but the end result is still much more coherent and predictable compared to traditional configuration management.

takeda12• 6 years ago

It's similar n some way, but totally rethinking the problem.

Ansible or saltstack are essentially programs that configure your system in specific way. Ansible takes more of a list of things what to change and how, while saltstack tries to be declarative.

NixOS is essentially a Linux system described using Nix language. Whenever you make change and run nixos-rebuild, as name suggests it actually rebuilds your entire system from scratch, it is just smart enough to not do work that was already done.

Benefits of it is that you will always get to the same state no matter what. Another benefit that is quite annoying with saltstack/ansible if you remove specific application/service/whatever once you rebuild the system, it is gone, like it was never there.

You also get Nix benefits, nix never leaves anything in half state changes are atomic, either they are applied successfully or not, if a change broke something, you can easily rollback. Things like for example changing KDE to Gnome or replacing Xorg with Wayland is no harder than replacing emacs with vim (or vim with emacs, if I upset you).

The way how Nix works allows different packages using even conflicting libraries. For example you can have two applications using different openssl version etc.

If you have one application and you need to apply a custom patch to it or maybe even use a different version. In traditional OS good sysadmins would create a custom RPM package an install it. In Nix you just override the definition, and if a cached build is not available, Nix will be smart enough to compile the code (this means no need for artifactory and uploading custom packages there, though to prevent recompiling every time, you should set up a caching server (there's also caching as a service option if you don't want to manage it) or you can even use S3 bucket.

Basically Nix and NixOS is rethinking how building/deploying/packaging does it offers many benefits, CMS like ansible/saltstack/chef/puppet/cfengine etc are no longer needed. It can be used for having comon developement environment, can be used for building, ci/cd etc.

ghuntley3• 6 years ago

Here's my dotfiles for some of my nixos servers and home computers.

https://github.com/ghuntley/dotfiles-nixos

Steal away and enjoy.

ghuntley3• 6 years ago

Check out the NixOS for existing sysadmins workshop over at — https://github.com/ghuntley/workshops/tree/master/nixos-work...

If you want a TL;DR overview of NixOS then start here — https://github.com/ghuntley/workshops/tree/master/nixos-work...

For an advanced example of overriding nixpkg and usage of pinning/override layers (ie some mandate or reason to run super old version of grpc) — https://github.com/digital-asset/daml/blob/master/nix/nixpkg...

gt565k2• 6 years ago

There's a good write up of how Cardano, the blockchain project, uses Nix.

Not surprising, given that Nix was a academic research project, and Cardano has a good network of academic researchers working to solve hard blockchain problems.

https://iohk.io/en/blog/posts/2019/02/06/how-we-use-nix-at-i...

My experience with NixOS

Related Stories