Nix/NixOS

Transcript

1. NIX/NIXOS
   ILUGC
   Sibi Prabakaran
   Jan 8, 2022
   

   View Slide

2. View Slide

3. AGENDA
   My experience with Nix/NixOS
   Introduction
   Why Nix
   

   View Slide

4. MY EXPERIENCE
   Tried NixOS around 5 years ago
   Initially used nixpkgs in Ubuntu
   For around ~1.5 years
   Using NixOS for ~ 1 year
   Maintainer of various packages
   

   View Slide

5. NIX/NIXPKGS/NIXOS
   Nix:
   Pure, lazy functional language.
   Not a general purpose language!
   Used for package description, composition
   Nixpkgs: Collection of packages.
   NixOS:
   Linux + nixpkgs
   System configuration also managed via Nix
   

   View Slide

6. WHY NIX/NIXOS
   Reproducibility
   bit identical
   Multiple versions of a software
   Atomic upgrades and rollbacks
   Declarative
   

   View Slide

7. BASIC WORKFLOW
   configuration.nix
   home manager
   writing script
   Usage is pretty similar to other distros.
   

   View Slide

8. NIX LANGUAGE
   Lazy, Functional and Pure
   Functions, Sets, Lists etc.
   Reference:
   https://nixos.wiki/wiki/Nix_Expression_Language
   

   View Slide

9. NIX EXPRESSION
   Code written in Nix language
   ❯ nix-instantiate --eval --expr "2 + 2"
   
   4
   
   ❯ cat example.nix
   
   2 + 2
   
   ❯ nix-instantiate --eval example.nix
   
   4
   

   View Slide

10. REAL WORLD NIX
    CODE
    Package:
    systemd service:
    amber
    cnx
    

    View Slide

11. NIX DERIVATIONS
    Recipe to build the end product.
    Reproducible & Deterministic
    ❯ fd -e drv nix /nix/store | head -n 5
    
    /nix/store/ix9j7fmxpfp7c0b2rn95wyy5y1803mya-nixos-
    manual.desktop.drv
    /nix/store/2a6ylyfsxb8knnana40fbnmk8ka7q1na-etc-
    nixos.conf.drv
    /nix/store/6r57mn57p9rgijr0lsfihkdkk2djkv86-nixos-
    manpages.drv
    /nix/store/ppsdnzviyi9q2xqak9qk0w16hpj30frj-nixos.conf.drv
    
    /nix/store/bp7flklzjxhm966b0d0pxi85dg4zbqpa-nix-prefetch-
    cvs.drv
    

    View Slide

12. DERVIATION..
    ❯ nix show-derivation derivation
    

    View Slide

13. COMMUNITY
    80,000 packages
    Easy to add package as compared to other
    distributions
    Images available for cloud providers
    nix-community organization
    

    View Slide

14. DISADVANTAGES
    No secure boot.
    Nix specific issues!
    Learning curve
    Debugging experience
    Size of user community
    Things are still changing: Flakes!
    

    View Slide

15. QUESTIONS
    

    View Slide