Nix introduction, essential ideas and instructions

Faheem

Tech Guides

Nix is a purposeful bundle supervisor for Linux and different Unix methods, making the administration of packages extra dependable and straightforward to breed.

With a conventional bundle supervisor, when updating a bundle, a brand new model is downloaded and used to overwrite its related information. Modifications can’t be undone. If for a purpose, a number of information will not be appropriately up to date throughout the improve, these information of the bundle are going to be corrupted. This might make the whole bundle not purposeful. As well as, if completely different packages require completely different variations of the identical bundle as a dependency, at the least one goes to be damaged.

This text presents what Nix bundle supervisor is, the assorted deployment choices and begin with it. Within the following article, we cowl the installation of NixOS, a Nix-based Linux distribution.

What’s Nix

Nix is a purposeful bundle supervisor. Under are the three essential advantages of utilizing Nix in contrast with a conventional bundle supervisor:

  • Nix brings reliability: putting in or upgrading one bundle don’t break different packages. It ensures that no bundle is inconsistent throughout an improve. Roll again to earlier variations is feasible.
  • Nix brings reproducibility: packages are constructed by Nix in isolation from one another. This ensures that they’re reproducible and don’t have undeclared dependencies, so if a bundle works on one machine, it really works on one other.
  • Nix is declarative: Nix makes it simple to share improvement and construct environments for tasks, no matter what programming languages and instruments are used.

With Nix, information are associated with symlinks. When a bundle is put in, symlinks level to a location contained in the Nix retailer listing, positioned in /nix/retailer. When upgrading a bundle, the brand new bundle information are extracted in a special location (no overwriting), the symlinks level then to the situation of latest information.

Utilization of symlinks to refers to packages have some benefits:

  • No danger of corruption between dependencies: a number of variations of the identical dependency might be put in
  • Much less storage requirement: the identical model of a dependency isn’t duplicated

The improve technique of a bundle creates what Nix calls a technology. It’s doable to roll again and to roll ahead by means of the earlier generations. This leaves the system totally purposeful as a result of one can all the time roll again to a earlier technology. It’s doable to save lots of and hold as many generations as needed. The draw back of that is the onerous drive area used to retailer the generations, however it’s doable to scrub out previous generations.

Nix deployment

Nix might be deployed on an current working system, both Linux or macOS, or utilizing NixOS which makes use of it from the bottom as much as create a Linux system.

Deployment by means of NixOS

NixOS is a Linux distribution constructed on high of Nix. The installation of NixOS share the steps of an alternate Linux distribution: partitioning and formatting of the disk earlier than set up of the working system. The official documentation provides steps to observe to deploy Nix by means of NixOS set up.

Deployment on an current working system

Nix is supported on Linux (i686, x86_64, aarch64) and macOS (x86_64, aarch64). Under are the instructions to put in Nix:

  • Linux

  • MacOS:

    sh (curl -L https://nixos.org/nix/set up)

Comply with the Official documentation for extra about set up on an current operation system.

Utilization of Nix

Consumer Surroundings

A Consumer Surroundings is a set of energetic functions. Completely different customers can have completely different environments and particular person customers can change between completely different environments. ~/.nix-profile is a symbolic hyperlink to the present consumer setting.

Managing a consumer setting is completed both by way of declarative configuration utilizing House Supervisor or by way of crucial operations utilizing nix-env instructions.

House Supervisor

House Supervisor is the popular technique to handle consumer environments. It permits declarative configuration of user-specific packages and information within the house listing. It’s put in by way of the instructions:

nix-channel --add https://github.com/nix-community/home-manager/archive/grasp.tar.gz home-manager

nix-channel --update
nix-shell '' -A set up
home-manager edit

The command home-manager edit installs House Supervisor, initializes and exposes the House Supervisor configuration file positioned at .config/nixpkgs/house.nix.

Every time one thing adjustments within the House Supervisor configuration file, the command beneath builds and prompts the configuration for the consumer.

Under is an edited model of the file house.nix to put in the bundle firefox and to configure git.

{ config, pkgs, ... }:

{
  
  
  house.username = "florent";
  house.homeDirectory = "/house/florent";

  
  house.packages = [
    
    pkgs.firefox
  ];

  
  applications.git = {
    allow = true;
    userName = "Florent";
    userEmail = "florent@adaltas.com";
  };

  
  
  
  
  
  
  
  
  house.stateVersion = "22.05";

  
  applications.house-supervisor.allow = true;
}

Be aware, various set up strategies combine House Supervisor with the NixOS and nix-darwin configuration. That is how we deploy our methods. Comply with the official documentation for extra particulars.

Nix crucial operations: nix-env

Consumer setting, together with bundle set up and removing, might be managed with the nix-env instructions. Under are a number of the most helpful instructions:

nix-env -iA nixpkgs.pkg-name>

  • To uninstall a bundle:

  • To improve a bundle:

    nix-env -u some-packages>

Instance: set up of virtualenv with Nix

Listed here are the steps to put in the bundle virtualenv utilizing the Nix bundle supervisor.

  • Seek for virtualenv utilizing the nix search command:

    nix search virtualenv
warning: utilizing cached outcomes; go '-u' to replace the cache
* nixpkgs.pew (pew-1.2.0)
Instruments to handle a number of virtualenvs written in pure python

* nixpkgs.python38Packages.pytest-virtualenv (python3.8-pytest-virtualenv)
Create a Python digital setting in your check that cleans up on teardown. The fixture has utility strategies to ins>

* nixpkgs.python38Packages.tox (python3.8-tox-3.23.0)
Virtualenv-based automation of check actions

* nixpkgs.python38Packages.virtualenv (python3.8-virtualenv)
A device to create remoted Python environments

* nixpkgs.python38Packages.virtualenv-clone (python3.8-virtualenv-clone)
Script to clone virtualenvs

* nixpkgs.python38Packages.virtualenvwrapper (python3.8-virtualenvwrapper)
Enhancements to virtualenv

* nixpkgs.python39Packages.pytest-virtualenv (python3.9-pytest-virtualenv)
Create a Python digital setting in your check that cleans up on teardown. The fixture has utility strategies to ins>

* nixpkgs.python39Packages.tox (python3.9-tox-3.23.0)
Virtualenv-based automation of check actions

* nixpkgs.python39Packages.virtualenv (python3.9-virtualenv)
A device to create remoted Python environments

* nixpkgs.python39Packages.virtualenv-clone (python3.9-virtualenv-clone)
Script to clone virtualenvs

* nixpkgs.python39Packages.virtualenvwrapper (python3.9-virtualenvwrapper)
Enhancements to virtualenv

    The search end result provides a number of choices to put in virtualenv. We chosen nixpkgs.python38Packages.virtualenv for the next instructions.

  • Set up nixpkgs.python38Packages.virtualenv

    • Choice 1: utilizing nix-env command:
    nix-env -iA nix-env -iA nixpkgs.python38Packages.virtualenv

    • Choice 2: utilizing House Supervisor

      The content material of the House Supervisor configuration file consists of:

      { config, pkgs, ... }:

{   
  ...
  
  house.packages = [
    
    ...
    nixpkgs.python38Packages.virtualenv
    ...
  ];
  ...
}

      To use the House Supervisor configuration:

    virtualenv is put in. Under are the instructions to create and activate a brand new python setting named myPythonEnv:

    virtualenv myPythonEnv 
supply myPythonEnv/bin/activate

Era

Each time a nix-env operation is completed, a revision of the consumer setting referred to as technology is newly created. Some instructions related to technology:

  • To checklist generations:

    nix-env --list-generations

  • To change to a selected technology:

    nix-env --switch-generation generation-number>

  • To take away particular generations:

    nix-env --delete-generations generation-numbers separated by area>

  • To roll again to the final nix-env command (to the final technology):

  • To delete older generations:

    nix-env --delete-generations previous

Profiles

Profiles are teams of generations in order that completely different customers don’t intrude with one another in the event that they don’t need to. Profiles and Consumer Environments are Nix’s mechanisms to permit completely different customers to make use of completely different configurations.

Derivation

A Derivation is a Nix expression describing all the things that goes right into a bundle construct motion (construct instruments, dependencies, sources, construct scripts, setting variables). It’s something wanted to construct up a bundle.

Channels

A channel is a git repository containing a listing of packages. Official channels are verified by Nix. Some instructions related to channels:

Rubbish assortment

When a bundle is uninstalled, it isn’t really deleted from the system even when no consumer refers to it. By this manner, it received’t be re-downloaded if it occurs that you just want it once more. Unsued packages are be deleted with the rubbish collector command:

Conclusion

Nix is a cross-platform bundle supervisor managing dependencies by itself effectively. It simplifies the method of managing a consumer setting by way of a declarative method and makes simple sharing of a consumer setting. Nevertheless, it comes with a steep studying curve. In my expertise, studying its utilization was price it.

Leave a Comment

© 2025 Tech Info Park by Faheem Mushtaq