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What Is Nix?

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Re: What Is Nix?

#11

Post by mehrdadn »

pjkundert wrote: post #6
dataflow wrote: post #2

I'm still confused. What is Nix? Is it an OS, or a package manager? From the looks of it it's a package manager that I should be able to use it on any POSIX system, but I doubt that's the case?

POSIX (eg. Linux), Mac and Windows. Yes, it is magnificent. Immutable, deterministic software on all 3 major platforms. Combined with cached build artifacts, builds and their outputs (including complete target system updates/upgrades) are blisteringly fast, cryptographically secure and completely deterministic. EDIT: Sorry, yes; Windows only via WSL, not natively on Windows proper.

Windows? You're kidding me! Where do I see Windows support? On their website I only see Mac and Linux.

Re: What Is Nix?

#12

Post by exdsq »

mehrdadn wrote: post #11
pjkundert wrote: post #6

Earlier quoted context omitted.

POSIX (eg. Linux), Mac and Windows. Yes, it is magnificent. Immutable, deterministic software on all 3 major platforms. Combined with cached build artifacts, builds and their outputs (including complete target system updates/upgrades) are blisteringly fast, cryptographically secure and completely deterministic. EDIT: Sorry, yes; Windows only via WSL, not natively on Windows proper.

Windows ? You're kidding me! Where do I see Windows support? On their website I only see Mac and Linux.

You can use it on WSL1 and WSL2 but you can't use it natively on Windows. I used it on WSL2 just this afternoon and it was seamless but that makes sense because WSL2 is basically just a Linux VM anyway.

Re: What Is Nix?

#13

Post by enriquto »

exdsq wrote: post #8
dataflow wrote: post #2

I'm still confused. What is Nix? Is it an OS, or a package manager? From the looks of it it's a package manager that I should be able to use it on any POSIX system, but I doubt that's the case?

One really cool thing about NixOS is you declare the OS just like you might a DockerFile, and you can choose which configuration file you use at booting time. This lets you install applications just during up-time (to try out a new tool), add it to the configuration file if you like it, and roll back to the version before if it breaks something. Versions are declarative too (PSql == X.X.X) and upgrades/downgrades are…

> One really cool thing about NixOS is you declare the OS just like you might a DockerFile,

But DockerFiles have a really terse, self-evident, trivial to read language. It is obvious what a given DockerFile means even if it's the first one you see.

For nix; well, I have seen a few nix files and each one leaves me more confused than the last. Can anybody point me to good examples of beautiful, single-file, complete, self-contained terse nix examples that describe a few simple systems? Everything that I seem to find are small fragments of stuff.

Re: What Is Nix?

#14

Post by throwaway894345 »

mehrdadn wrote: post #10
statenjason wrote: post #3

Earlier quoted context omitted.

What is Nix? Nix is a powerful package manager for Linux and other Unix systems that makes package management reliable and reproducible. It provides atomic upgrades and rollbacks, side-by-side installation of multiple versions of a package, multi-user package management and easy setup of build environments. What is NixOS? NixOS is a Linux distribution with a unique approach to package and configuration management. Bu…

Thanks, but that makes me wonder how that's even possible given that distros make their own modifications? Do people port each distro's packages to Nix then? Are they kept up-to-date? Or does it automatically translate from apt/pacman/etc. databases somehow? Or does it just basically install vanilla packages on all distro?

Yeah, there is a giant repo of package definitions at https://github.com/NixOS/nixpkgs. Those definitions tell nix how to build everything from the ground up.

Re: What Is Nix?

#15

Post by mehrdadn »

lmickh wrote: post #7
dataflow wrote: post #2

I'm still confused. What is Nix? Is it an OS, or a package manager? From the looks of it it's a package manager that I should be able to use it on any POSIX system, but I doubt that's the case?

It is pretty easy to be confused. Especially since it is also a language yet all the other replies at the time have writing have failed to mention that. While I like the project as a whole, their naming is horrible. Just wait until you get into `nix-env` vs `nix-shell` etc...

Thanks, yeah. Conceptually I'm having a hard time wrapping my head around it since package managers are so tightly tied to an OS... I feel like surely I can't just use it in place of (say) apt or pacman without causing problems? And I haven't even gotten to the language/shell/etc. as you mention...

Re: What Is Nix?

#16

Post by tathougies »

mehrdadn wrote: post #10
statenjason wrote: post #3

Earlier quoted context omitted.

What is Nix? Nix is a powerful package manager for Linux and other Unix systems that makes package management reliable and reproducible. It provides atomic upgrades and rollbacks, side-by-side installation of multiple versions of a package, multi-user package management and easy setup of build environments. What is NixOS? NixOS is a Linux distribution with a unique approach to package and configuration management. Bu…

Thanks, but that makes me wonder how that's even possible given that distros make their own modifications? Do people port each distro's packages to Nix then? Are they kept up-to-date? Or does it automatically translate from apt/pacman/etc. databases somehow? Or does it just basically install vanilla packages on all distro?

> how that's even possible given that distros make their own modifications?

Own modifications to what? All the packages in nixpkgs depend only on other packages in nixpkgs. If you install nix on an ubuntu system and then install a package from nixpkgs, then that package won't use any ubuntu libraries.

Re: What Is Nix?

#17

Post by throwaway894345 »

enriquto wrote: post #13
exdsq wrote: post #8

Earlier quoted context omitted.

One really cool thing about NixOS is you declare the OS just like you might a DockerFile, and you can choose which configuration file you use at booting time. This lets you install applications just during up-time (to try out a new tool), add it to the configuration file if you like it, and roll back to the version before if it breaks something. Versions are declarative too (PSql == X.X.X) and upgrades/downgrades are…

> One really cool thing about NixOS is you declare the OS just like you might a DockerFile, But DockerFiles have a really terse, self-evident, trivial to read language. It is obvious what a given DockerFile means even if it's the first one you see. For nix; well, I have seen a few nix files and each one leaves me more confused than the last. Can anybody point me to good examples of beautiful, single-file, complete, s…

This is because Nix needs to express a lot more so builds are reproducible and incremental. Docker doesn’t care about these things.

Re: What Is Nix?

#18

Post by lmickh »

mehrdadn wrote: post #15
lmickh wrote: post #7

Earlier quoted context omitted.

It is pretty easy to be confused. Especially since it is also a language yet all the other replies at the time have writing have failed to mention that. While I like the project as a whole, their naming is horrible. Just wait until you get into `nix-env` vs `nix-shell` etc...

Thanks, yeah. Conceptually I'm having a hard time wrapping my head around it since package managers are so tightly tied to an OS... I feel like surely I can't just use it in place of (say) apt or pacman without causing problems? And I haven't even gotten to the language/shell/etc. as you mention...

You use the language to define the configuration, packages, and etc. NixOS isn't so much an OS configured by a package manager as much as it is an OS + package manager that you can configure with the Nix language.

Then there is also lot of tooling to hid all of the symlink magic. It is very deep rabbit hole. Most of the quick touch examples will basically look like magic.

Re: What Is Nix?

#19

Post by mehrdadn »

tathougies wrote: post #16
mehrdadn wrote: post #10

Earlier quoted context omitted.

Thanks, but that makes me wonder how that's even possible given that distros make their own modifications? Do people port each distro's packages to Nix then? Are they kept up-to-date? Or does it automatically translate from apt/pacman/etc. databases somehow? Or does it just basically install vanilla packages on all distro?

> how that's even possible given that distros make their own modifications? Own modifications to what? All the packages in nixpkgs depend only on other packages in nixpkgs. If you install nix on an ubuntu system and then install a package from nixpkgs, then that package won't use any ubuntu libraries.

> Own modifications to what?

To the packages. e.g. I believe Ubuntu modifies Python so that sudo pip install uses /usr/local instead of /usr. Lots of other patches and backports I'm not necessarily aware of. That's basically what makes Ubuntu Ubuntu, otherwise it'd be more like Arch. So how does Nix deal with this? Do you get the value-add from your distro or do you basically end up with pseudo-Arch wherever you start?

Re: What Is Nix?

#20

Post by tel »

dataflow wrote: post #2

I'm still confused. What is Nix? Is it an OS, or a package manager? From the looks of it it's a package manager that I should be able to use it on any POSIX system, but I doubt that's the case?

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 the things you'd expect to be able to fetch from brew or apt. Each derivation encodes the steps to use Nix (the build system) to construct that output.

NixOS is a Linux distribution built atop Nix, Nix, and Nixpkgs. The basic claim to fame here is "totally declarative system setup" where you write all of the configuration for your system in Nix, using Nixpkgs and some other NixOS specific tooling and libraries, and then "build" the entire system with high repeatability.

Then there are a few other related projects such as Hydra (a CI server and binary cache builder—most of the time you don't build with Nix, just download the proper thing from the cache) and NixOps (an extension to NixOS which provisions whole fleets of servers declaratively).

Finally, you don't need to run NixOS in order to benefit from Nix. Nix and Nixpkgs are (largely) compatible with MacOS and Linux. That means you can install Nix onto your existing MacOS or Linux system and use it a lot like you'd use brew or apt. That said, the premiere Nix experience is always NixOS.

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