NixOS - Purely Functional Package Management

Transcript

1. Nix(OS) purely functional package management Fueled by
2. f(x)
3. Why is state evil?
4. Expensive to keep track of mutation
5. Which in turns means no rollback
6. Which in turns means no portability
7. The Nix language
8. Why?
9. $ nix-repl > true true > 1 + 1 2 > (a: a + 1) 1 2
10. We use Nix to describe how to build packages
11. { stdenv, fetchurl, perl }: stdenv.mkDerivation { name = "hello-2.1.1"; builder = ./builder.sh; src = fetchurl { url = “${packageURL}; md5 = “${md5hash}; }; inherit perl; }
12. Packages are immutable once built
13. Everything lives inside a single directory, the store
14. “Live” packages are symlinked
15. Old packages are still in the store, just not accessible
16. Rollback for free
17. Multiple versions for free
18. Multiple envs for free
19. Puppies for free
20. Ok, maybe not puppies
21. $ nix-repl command not found: nix-repl $ nix-shell -p nix-repl [nix-shell:~]$ nix-repl -v nix-repl v1.1.2 [nix-shell:~]$ exit $ nix-repl command not found: nix-repl
22. NixOS is a distribution built around Nix
23. In Nix, to build a package you write a function
24. In NixOS, to build a system you write a function
25. configuration.nix
26. $ fdisk /dev/sda $ mkfs.ext4 -L nixos /dev/sda1 $ mkswap -L swap /dev/sda2 $ swapon /dev/sda2 $ mount /dev/disk/by-label/nixos /mnt $ nixos-generate-config --root /mnt $ nano /mnt/etc/nixos/configuration.nix $ nixos-install $ reboot
27. { config, pkgs, ... }: { imports = [ ./hardware-configuration.nix ]; boot.loader.grub.device = "/dev/sda"; }
28. Building your system is purely functional
29. Upgrading is the same as rebuilding from scratch
30. No /usr, /sbin/, /share
31. Just /nix/store
32. Nix(OS) cryoptographically hashes all build inputs
33. That means built-in versioning
34. dotfiles, just store ‘em in /nix/store .emacs.d, *wink* *wink* ;) ;)
35. More than just a distribution
36. nixops
37. (hail) hydra
38. Questions?