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What Is Nix?

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Re: What Is Nix?

#131

Post by takeda »

mehrdadn wrote: post #33
tel wrote: post #20

Earlier quoted context omitted.

It's kind of a mess. Nix is a collection of tools and systems that together form a highly reproducible build system. Nix is also a declarative, largely pure and lazy programming language that you use to design and specify the different build outputs for the Nix build system. Nixpkgs is, more or less, the only project written using Nix (and a lot of shell). It's a collection of many thousands of "derivations", many of…

Thanks! So let's say I start installing Nix packages. What distro's packages would they end up most similar to? Say, maybe Arch (which mostly leaves things unmodified)? Does that mean you basically end up with Arch no matter which distro you're on?

GuixSD? Only because Guix was build from Nix.

Frankly I don't think there's anything else like it. I don't know Arch enough to compare, but there's something also similar to Gentoo, except Nix knows that if source + dependencies + architecture + configuration is the same it will pull compiled version from cache, if something changes it will recompile it.

The killer NixOS feature is that it has a single configuration file that's declarative which you can use to describe your OS, so it has something like salt/ansible/chef/puppet built in, and unlike them it's also is truly declarative. For example if you have package installed, to remove it, you just remove it from the list, where in those tools you need to create a state that ensures the package must not be present.

Edit: from other comments I see that you meant that packages in arch are not modified, I guess Nix does follow that and only add patches if it absolutely needs them to make application work correctly, but unlike other distros nix also allows user trivially (ignoring the steep curve to learn nix :) to modify a derivation (for example applying patches, changing dependencies, changing ./configure flags) similarly how you would extend a class in OO language. In any other OS to do such customization, you would need to generate a new package, place it in package repo, and worry about your modified package breaking other parts of the system. NixOS will then recompile that package and use it (if you use caching it will pull from cache)

Re: What Is Nix?

#132

Post by mason55 »

addicted wrote: post #128
yawaramin wrote: post #77

Earlier quoted context omitted.

Sounds like their main concern wasn't Nix but the complexity of the code itself.

The hours long build system appears to be attributed to Nix. Is Nix really that slow?

Dependencies can take awhile if you can’t used cached versions of the binaries. Building some Haskell tooling from scratch took ~3 hours on my MBP.

Re: What Is Nix?

#133

Post by geofft »

addicted wrote: post #128
yawaramin wrote: post #77

Earlier quoted context omitted.

Sounds like their main concern wasn't Nix but the complexity of the code itself.

The hours long build system appears to be attributed to Nix. Is Nix really that slow?

If you're applying idiomatic Nix to modern JS, I wouldn't be surprised - modern JS tends to involve installing thousands of packages by just combining them into a directory, but Nix doesn't want you to edit existing directories. So your dependency graph turns into a build-dependency graph, with each JS package requiring a full build of everything it depends on, and the Nix build system is presumably not optimized for fast turnaround times on five-line JS modules that don't even have a compilation step.

(Personally, I wouldn't try to apply idiomatic Nix to modern JS - I'd apply it to the major components like "my web server" and "my database library" and have "all the JS I depend on" as one big Nix package. That's not really a claim about Nix, I wouldn't try to apply idiomatic, say, Debian packaging to modern JS either. In both cases I'd still get about 90% of the benefit of using Nix/Debian as a delivery mechanism.)

The other thing that could be slow is if you start compiling all your dependencies, including gcc and node.js, from scratch. While there's some security benefit in doing so, the reality is that just about nobody actually does that. You'd want to set things up to use the precompiled packages, or at least set up your own cache server and have compiled binaries you trust but only do it once.

Re: What Is Nix?

#134

Post by karatestomp »

Kinrany wrote: post #83
illumin8 wrote: post #70

Earlier quoted context omitted.

I've had the (dis)pleasure of working with several projects that have been built by developers that have religion around Nix. These projects were contract work where the client paid a significant amount of money, and the final product was really poor quality. One of them is a financial application that has strict security requirements, so having a reproducible build system and some of the other qualities of Nix sound…

So the auditors said that the system was hard to audit?

Considering that “difficult to audit” overlaps with: difficult to understand, difficult to deploy, difficult to onboard, and a bunch of other things that are also very important to non-auditors, that seems like an entirely reasonable and informative complaint.

If you hire a financial auditor and their report was basically an nicer version of “‘books‘ were written in pencil on napkins, many food stained, some illegible. Attempting to make sense of them took forever. Fix this shit to meet minimum standards for business accounting, it’s entirely unsuitable for its purpose” that’s be great info, if you didn’t already know it.

Re: What Is Nix?

#135

Post by takeda »

tel wrote: post #64
mehrdadn wrote: post #33

Earlier quoted context omitted.

Thanks! So let's say I start installing Nix packages. What distro's packages would they end up most similar to? Say, maybe Arch (which mostly leaves things unmodified)? Does that mean you basically end up with Arch no matter which distro you're on?

In addition to other answers, I think it's important to note that Nix is comparatively very small (but growing!). To that end, the Nixpkgs policies are still in flux and defined somewhat culturally (at least compared to older, larger distros). There's a release schedule for NixPkgs which is being continuously updated, you mostly subscribe to a fixed "channel" which gives you the default set of derivations. If you nee…

> That said, the returns on using this weird technology are really high. The short pitch is something like "zero runtime cost, highly repeatable Docker containers for everything". Of course, the technology works nothing like that, but it really hit some of the big position independence value props of Docker in a way that's lightweight enough to use it for everything.

It simply delivers what docker was promising to deliver.

Re: What Is Nix?

#136

Post by inetknght »

nilkn wrote: post #129

This article is a good explanation of how nix works at a high level, and I'm excited to see nix getting some really prominent support, but for some reason it never tells you what the point of all of this is, so I think many folks might feel turned off by it. In other words, I don't believe it ever compellingly answers the question that constitutes its title. The word "package" doesn't even appear until near the end o…

So... statically compiled executables?

Wasn't that tried long ago and it was determined that the user should be able to choose when to upgrade dependencies, such as if a dependency needs an out-of-band update to work on the localhost OS?

Re: What Is Nix?

#137

Post by bradly »

burke wrote: post #89
LockAndLol wrote: post #72

This article suffers from the same problem every nix article I read suffers from: it dives in too deep from the get go. When you sit somebody down in front of a computer for the first time in their life, you're not going to explain what it is composed of, what happens in when your mouse button is clicked and why Windows vs Mac vs Linux is a thing. Please, first tell me what nix is, provide me with a few commands to g…

That's kind of the approach I took in this playlist: https://www.youtube.com/playlist?list=PLRGI9KQ3_HP_OFRG6R-p4... However, there is really an important and subtle set of concepts to grasp in order to actually understand Nix, and not just mess around with a package manager tool incidentally built with it. It's fine to not understand them, but they are what this article tries to explain.

FWIW... I read this article as someone who doesn't know what Nix is. Like no idea at all besides the name sounding familiar. After reading the first few paragraphs I feel I'm not the target audience for the article, which it totally fine, but based on the title of the post, I assumed I was.

Re: What Is Nix?

#138

Post by all_blue_chucks »

bulldoa wrote: post #87
illumin8 wrote: post #70

Earlier quoted context omitted.

I've had the (dis)pleasure of working with several projects that have been built by developers that have religion around Nix. These projects were contract work where the client paid a significant amount of money, and the final product was really poor quality. One of them is a financial application that has strict security requirements, so having a reproducible build system and some of the other qualities of Nix sound…

Woah, I didn't know there is an entire ecosystem of contract job and auditors for big projects. How do companies usually hire contract jobs (outsourced HR, upwork, Accenture)? And how do they hire auditors?

This sounds like a security audit, and auditors found the build system difficult to work with when attempting to audit code.

Re: What Is Nix?

#139

Post by nerdponx »

nilkn wrote: post #129

This article is a good explanation of how nix works at a high level, and I'm excited to see nix getting some really prominent support, but for some reason it never tells you what the point of all of this is, so I think many folks might feel turned off by it. In other words, I don't believe it ever compellingly answers the question that constitutes its title. The word "package" doesn't even appear until near the end o…

What I'd really like to see is a realistic, end-to-end tutorial for either 1) deploying a relatively straightforward web application (like Dokuwiki or ZNC), or 2) setting up a basic desktop for day-to-day use. I feel like I've seen a lot of "snippets", I feel like I understand how Nix works and what it's supposed to be good for, but I don't have a coherent sense of the steps involved in actually using it for mundane things.

Re: What Is Nix?

#140

Post by tomberek »

downerending wrote: post #91
tomberek wrote: post #86

Nix is a powerful package manager. I can confidently compile and run multiple incompatible versions of software simultaneously. I can build projects from years ago. I can package large projects from different ecosystems (python 2/3, c/c++, go, javascript) and be confident they will not interfere with each other. I can try bleeding edge software with no risk to it interfering with my system. It is faster and less hass…

As an example, what's minimally required to run two different versions of program-x from the command line. Can I do something like this easily? cat-8.22 /etc/passwd | cat-8.3 -A

Minimal example:

  export v824=$(nix-build 'channel:nixos-15.09-small' -A coreutils)
  export v830=$(nix-build 'channel:nixos-19.09-small' -A coreutils)
  $v824/bin/cat /etc/passwd | $v830/bin/cat -A
You can get better specificity by using a nixpkgs git repo/hash instead of channel or adding `--no-out-link`, but this is minimal.
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