20 KiB
NixOS
- NixOS
- NixOS installation
- Remote installation: disko and nixos-anywhere
- ARM device: SD image for the Raspberry Pi 3B+
- ARM device: Vanilla UEFI boot loader for the Raspberry Pi 3B+
- Update, build and switch
- niv: Dependency management
- Colmena: Deployment and secret management
- BTRFS swap file
- LUKS Parameters
- Automount encrypted drive
- Failed services
- Garbage collection
- Run AppImages
- General Notes
- TODOs
NixOS installation
Graphical installation
For beginners, NixOS can be installed with a graphical installer.
Getting the ISO:
- There is no official torrent as they are not needed due to CDN.
- ISO and checksum are available here: https://nixos.org/download#nixos-iso
- There are unofficial torrents. If the checksum is compared with the one from the official website, these can be used as well: https://github.com/AnimMouse/NixOS-ISO-Torrents/releases
During installation:
- If the installation target is a SSD
- Trim the whole disk to mark all cells as unused and restore its initial performance
sudo blkdiscard -f /dev/nvmeXXX
- Select manual partitioning:
- One 512MB (or larger) Fat32 partition, mounted at
/boot
, "boot" flag enabled - Another partition (e.g. BTRFS) covering the rest of the drive, mounted at
/
, encryption enabled
- One 512MB (or larger) Fat32 partition, mounted at
Remote installation: disko and nixos-anywhere
Install NixOS via SSH everywhere.
There is a separate repository for these steps. Its README can be found here: https://codeberg.org/privacy1st/nixos-anywhere-example/src/template/README.md
ARM device: SD image for the Raspberry Pi 3B+
ISO
If you are on an architecture other than aarch64, enable emulation: boot.binfmt.emulatedSystems = [ "aarch64-linux" ];
.
An ISO for the Raspberry Pi 3B+ can then be built with:
# If on aarch64
#nix-build '<nixpkgs/nixos>' -A config.system.build.sdImage -I nixos-config=./iso-aarch64.nix
# If not on aarch64
nix-build '<nixpkgs/nixos>' -A config.system.build.sdImage -I nixos-config=./iso-aarch64.nix --argstr system aarch64-linux
ls result/sd-image/*.img
Note about cross compilation
Alternatively to emulating the aarch64 architecture we could also cross compile from e.g. x86 to it. However, this has one big drawback: The binary cache (https://cache.nixos.org/) won't be used. The reason for this is that packages built with cross compilation are (slightly) different from native built ones. Their checksums don't match.
Default configuration
When the Raspberry Pi is booted, run nixos-generate-config
to generate the default configuration.nix
and hardware-configuration.nix
files.
A slightly modified config can be found in ./hosts/pi3bplus/
Apply modified configuration
The Rapberry Pi 3B+ has only 1GB RAM, which is not enough for nixos-rebuild
. It is recommended to create and activate a SWAP file first: https://wiki.archlinux.org/title/swap#Swap_file_creation
nix-channel --list
#=> nixos https://nixos.org/channels/nixos-23.05
nix-channel --update nixos
passwd
nixos-rebuild boot
reboot
ARM device: Vanilla UEFI boot loader for the Raspberry Pi 3B+
TODO: The EFI menu was working. But I got many squashfs errors when booting an USB stick with the NixOS installer.
Preparing a micro SD card with an UEFI boot loader:
nix-shell -p parted gptfdisk
sudo parted --script /dev/SDX -- \
mklabel gpt \
mkpart ESP fat32 2Mib 512MiB \
set 1 esp on \
mkpart primary 512MiB 100% \
print
sudo wipefs --all /dev/SDX1
sudo wipefs --all /dev/SDX2
sudo mkfs.fat -F32 /dev/SDX1
sudo gdisk /dev/SDX
# r
# p
# h
# 1
# N
# 0c
# N
# N
# o
# w
# Y
In addition to the SD card, attach an USB stick with NixOS ARM (https://nixos.org/download.html#nixos-iso, https://hydra.nixos.org/job/nixos/release-23.05/nixos.iso_minimal.aarch64-linux, https://hydra.nixos.org/job/nixos/release-23.05/nixos.iso_minimal_new_kernel_no_zfs.aarch64-linux or https://hydra.nixos.org/job/nixos/trunk-combined/nixos.iso_minimal.aarch64-linux) to the Raspberry Pi.
sudo umount /dev/SDX
sudo dd if=nixos-minimal-XXX-aarch64-linux.iso of=/dev/SDX bs=4M conv=fsync
Then install NixOS the way you prefer, but don't touch/modify the partition table!
See https://nixos.wiki/wiki/NixOS_on_ARM/UEFI#Installing
Update, build and switch
Local (yodaTux):
niv update && colmena build --on yodaTux -v && colmena apply-local --sudo
Server:
niv update && colmena build --on @server -v && colmena apply --on @server switch
Update
- Updating NixOS. https://superuser.com/a/1604695
Update channel and configuration:
sudo nix-channel --update && niv update
To apply the updates, continue with "Build and switch".
Build and switch: Using Colmena
See section "Colmena: Deployment and secret management" to build and apply updates.
Build and switch: Manually
- https://nixos.wiki/wiki/Nixos-rebuild
- https://discourse.nixos.org/t/how-to-get-this-pending-updates-notification-in-gnome/16344/3
- https://discourse.nixos.org/t/how-to-get-this-pending-updates-notification-in-gnome/16344/6
Option I: Build new config and activate it:
sudo nixos-rebuild -I nixos-config=hosts/$(hostname)/configuration.nix switch
To view changes, see section "Compare two versions of NixOS system profile".
Option II: Build new config and activate it during next boot:
sudo nixos-rebuild -I nixos-config=hosts/$(hostname)/configuration.nix boot
Option III: Build config and view changes:
# This leaves a symlink named `result` in the current directory.
sudo nixos-rebuild -I nixos-config=hosts/$(hostname)/configuration.nix build
nix --extra-experimental-features nix-command store diff-closures /run/current-system ./result
#=> ...
#=> linux: 6.1.47, 6.1.47-modules → 6.1.51, 6.1.51-modules, -11.8 KiB
Depending on if there are large kernel changes, either switch to it directly or wait until next boot:
sudo ./result/bin/switch-to-configuration switch
# or
sudo ./result/bin/switch-to-configuration boot
Note: The Perl script executed by both above commands should create a new bootloader menu entry and mark it as default. However, if I remember correctly, the menu entry was once missing and the configuration change thus not permanent. This might need further testing. See also: https://nixos.wiki/wiki/Nixos-rebuild#Internals
niv: Dependency management
niv:
Easy dependency management for Nix projects.
Nix is a very powerful tool for building code and setting up environments. niv complements it by making it easy to describe and update remote dependencies (URLs, GitHub repos, etc). It is a simple, practical alternative to Nix flakes.
Niv is an easy dependency management for Nix projects with package pinning.
Initialize:
niv init
Change the tracking branch of nixpkgs from unstable to 23.05:
niv modify nixpkgs --branch nixos-23.05
Add nixpkgs unstable:
niv add NixOS/nixpkgs -n unstable -b nixpkgs-unstable
Add Home Manager with niv
Home Manager:
[Home Manager] allows declarative configuration of user specific (non-global) packages and dotfiles.
To avoid breaking users' configurations, Home Manager is released in branches corresponding to NixOS releases ( e.g.
release-23.05
).Home Manager provides both the channel-based setup and the flake-based one.
Check your channel:
sudo nix-channel --list
#=> nixos https://nixos.org/channels/nixos-23.05
Use the corresponding branch:
niv add nix-community/home-manager -n home-manager -b release-23.05
Add NUR with niv
The Nix User Repository (NUR) is community-driven meta repository for Nix packages.
... packages are built from source and are not reviewed by any Nixpkgs member.
niv add nix-community/NUR -n NUR
Colmena: Deployment and secret management
Colmena is a simple, stateless NixOS deployment tool modeled after NixOps and morph, written in Rust.
Alternative: Deployment with Morph: https://xeiaso.net/blog/morph-setup-2021-04-25
Configuration is done inside hive.nix.
Build config:
colmena build -v
Apply to all non-local nodes:
colmena apply --on @server switch
#colmena apply --on @server boot
#colmena apply --on @yodaTab switch
#colmena apply --on @yodaTab boot
Apply to local node:
colmena apply-local --sudo switch
#colmena apply-local --sudo boot
Filtering:
- You can filter hosts by tags with
--on @tag-a,@tag-b
. - You can use globs in tag matching as well:
colmena apply --on '@infra-*'
BTRFS swap file
Summary:
- Create subvolume
@swap
directly below top-level subvolume. - Mount at
/swap
- Create swapfile:
sudo btrfs filesystem mkswapfile --size 8g --uuid clear /swap/swapfile
- Regenerate hardware-configuration:
sudo nixos-generate-config --dir hosts/$(hostname)
- Add
swapDevices = [ { device = "/swap/swapfile"; } ];
to hardware configuration and runnixos-rebuild switch
(see above).
LUKS Parameters
Warning: NixOS has a hardcoded timeout of 10 seconds when opening encrypted drives during boot. Please choose --iter-time
<= 5000
.
ed2ccd4d17/nixos/modules/system/boot/luksroot.nix (L498)
ed2ccd4d17/nixos/modules/system/boot/luksroot.nix (L30)
ed2ccd4d17/nixos/modules/system/boot/luksroot.nix (L36C7-L36C7)
Automount encrypted drive
* Generate and add keyfile to LUKS device
- Use the same password for all attached LUKS devices to be only prompted once while booting
- luksOpen and mount drive, e.g. to
/mnt/data1
- Re-generate hardware configuration:
sudo nixos-generate-config --dir hosts/$(hostname)
- If it is an SSD, enable
boot.initrd.luks.devices.<name>.allowDiscards
Failed services
If there are e.g. file conflicts due to preexisting dotfiles, the Home Manager user service might fail. To list all failed services, run:
systemctl --failed
Garbage collection
- https://nixos.org/manual/nix/stable/package-management/garbage-collection.html
- https://discourse.nixos.org/t/why-doesnt-nix-collect-garbage-remove-old-generations-from-efi-menu/17592/4
This is automated in base.nix with the nix.gc
option.
Run manually for all profiles:
sudo nix-collect-garbage --delete-older-than 14d
Remove leftover EFI entries of removed generations:
sudo /run/current-system/bin/switch-to-configuration boot
Run AppImages
# Note how your shell prefix changes.
nix-shell -p appimage-run
# Inside the shell, you can run an AppImage:
appimage-run ~/Downloads/ubports-installer_0.10.0_linux_x86_64.AppImage
General Notes
- There is controversy about flakes, rather use channels (e.g. with niv)
- Prins, P., Suresh, J. and Dolstra, E., "Nix fixes dependency hell on all Linux distributions," Archived December 26, 2008, at the Wayback Machine linux.com, December 22, 2008
Nix Pills
It provides a tutorial introduction into the Nix package manager and Nixpkgs package collection, in the form of short chapters called 'pills'.
Papers
Papers about Nix:
- The Purely Functional Software Deployment Model (2006). http://nixos.org/~eelco/pubs/phd-thesis.pdf, https://edolstra.github.io/pubs/phd-thesis.pdf, https://github.com/edolstra/edolstra.github.io/blob/master/pubs/phd-thesis.pdf
- May 2023: Some insights from the thesis in short form. https://jonathanlorimer.dev/posts/nix-thesis.html
- NixOS: A Purely Functional Linux Distribution (2008): https://github.com/edolstra/edolstra.github.io/blob/master/pubs/nixos-icfp2008-final.pdf, https://github.com/edolstra/edolstra.github.io/blob/master/pubs/nixos-jfp-final.pdf
- Nix: A Safe and Policy-Free System for Software Deployment (2004): https://edolstra.github.io/pubs/nspfssd-lisa2004-final.pdf
System information
nix-info -m
- system: `"x86_64-linux"`
- host os: `Linux 6.1.51, NixOS, 23.05 (Stoat), 23.05.3242.da5adce0ffaf`
- multi-user?: `yes`
- sandbox: `yes`
- version: `nix-env (Nix) 2.13.5`
- channels(root): `"nixos-23.05"`
- nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos`
Search for packages
Search for options
- https://search.nixos.org/options?channel=23.05
- Or
man configuration.nix
- Or
- https://mipmip.github.io/home-manager-option-search
- Or
man home-configuration.nix
- Or
Search wich package owns a file
# Note how your shell prefix changes.
nix-shell -p nix-index
# Either build the index manually (requires >12GB RAM):
nix-index
# Or download weekly build:
mkdir -p ~/.cache/nix-index/ && wget -q -N https://github.com/nix-community/nix-index-database/releases/latest/download/index-x86_64-linux -O ~/.cache/nix-index/files
# Then search for a file
nix-locate --whole-name '/bash'
List files of package
Example for nano
:
find $(nix-build '<nixpkgs>' -A nano --no-link)
Excerpt of the result:
/nix/store/jqvxmx65mfinbsm6db9kmcqmphl44xhp-nano-7.2/share/nano
/nix/store/jqvxmx65mfinbsm6db9kmcqmphl44xhp-nano-7.2/share/nano/asm.nanorc
/nix/store/jqvxmx65mfinbsm6db9kmcqmphl44xhp-nano-7.2/share/nano/autoconf.nanorc
Compare two versions of NixOS system profile
Get latest system profile. This is the profile (usually) being active after booting the system:
ls -1 /nix/var/nix/profiles/ | sort -t'-' -n -k2 | tail -n 1
#=> 120
Compare current with previous profile:
# https://stackoverflow.com/a/36641298
prev="$(ls -1 /nix/var/nix/profiles/ | sort -t'-' -n -k2 | tail -n 2 | head -n 1)"
curr="$(ls -1 /nix/var/nix/profiles/ | sort -t'-' -n -k2 | tail -n 1)"
nix --extra-experimental-features nix-command store diff-closures /nix/var/nix/profiles/"${prev}" /nix/var/nix/profiles/"${curr}"
Compare two arbitrary system profiles:
nix --extra-experimental-features nix-command store diff-closures /nix/var/nix/profiles/system-110-link /nix/var/nix/profiles/system-116-link
cpupower: 6.1.47 → 6.1.51
element-desktop: 1.11.38 → 1.11.40, +2218.9 KiB
element-web: 1.11.38 → 1.11.40, -73.1 KiB
exempi: 2.6.3 → 2.6.4
firefox: 116.0.3 → 117.0
firefox-unwrapped: 116.0.3 → 117.0, -292.6 KiB
gnome-shell-extension-openweather: ∅ → 121, +590.5 KiB
hm_fontconfigconf.d10hmfonts.conf: ∅ → ε
initrd: ∅ → ε
initrd-linux: 6.1.47 → 6.1.51
libcap: 2.68 → 2.69
linux: 6.1.47, 6.1.47-modules → 6.1.51, 6.1.51-modules, -11.8 KiB
meld: ∅ → 3.22.0, +3858.5 KiB
net-snmp: 5.9.3 → 5.9.4
nixos-system-yodaTab: 23.05.3085.2ab91c8d65c0 → 23.05.3242.da5adce0ffaf
openjdk: +19.5 KiB
python3.10-pygobject: +27.0 KiB
stage: ∅ → 1-init.sh, +29.5 KiB
tor-browser-bundle-bin: 12.5.2 → 12.5.3, +18.1 KiB
user: +2885.0 KiB
NixOS configuration debugging
Evaluating parts of the configuration.
First, start nix repl
:
nix repl --file '<nixpkgs/nixos>' -I nixos-config=hosts/$(hostname)/configuration.nix
Example: config.home-manager
config.home-manager.
# Press `TAB`
#=> config.home-manager.backupFileExtension config.home-manager.useUserPackages
#=> config.home-manager.extraSpecialArgs config.home-manager.users
#=> config.home-manager.sharedModules config.home-manager.verbose
#=> config.home-manager.useGlobalPkgs
Example: The home
variable:
config.home-manager.users.yoda.home
Example: The value of one config option
# The following option is set to `"${config.xdg.dataHome}/.histfile";`
# where `config` is the Home Manager configuration.
config.home-manager.users.yoda.programs.zsh.history.path
#=> "/home/yoda/.local/share/.histfile"
Show Nix configuration
nix --extra-experimental-features nix-command show-config
Evaluate NixOS configuration to JSON
See also section "NixOS Configuration Debugging"!
This evaluates configuration.nix
(single module):
NIXPKGS_ALLOW_UNFREE=1 nix-instantiate --strict --json --eval -E '
import ./hosts/yodaTab/configuration.nix {
config = {};
pkgs = import <nixpkgs> {};
lib = import <nixpkgs/lib>;
}
' > evaluated-config.json
Then open evaluated-config.json
.
References
Some references to websites that helped me create this repository:
- https://github.com/Misterio77/nix-starter-configs
- https://github.com/mikeroyal/NixOS-Guide#getting-started
TODOs
-
Nitrokey LUKS unlock
- Yubikey LUKS: https://nixos.wiki/wiki/Yubikey_based_Full_Disk_Encryption_(FDE)_on_NixOS
- Yubikey LUKS: https://github.com/georgewhewell/nixos-host/blob/master/profiles/luks-yubi.nix
- Old wiki entry, initramfs smartcard LUKS unlock: https://wiki.ubuntu.com/SmartCardLUKSDiskEncryption#SmartCard_Setup
-
Nitrokey PAM log-in
- https://docs.nitrokey.com/pro/linux/login-with-pam
- You have two options:
pam_p11
orPAM Poldi
. - The solution with pam_p11 is more difficult to achieve and is based on S/MIME certificates.
- You have two options:
- I could not find pam-poldi for NixOS :/
- https://docs.nitrokey.com/pro/linux/login-with-pam
-
Impermanence, opt-in to persistence: https://github.com/Misterio77/nix-starter-configs/tree/main#try-opt-in-persistance
-
nix-shell / lorri
- https://ghedam.at/15978/an-introduction-to-nix-shell
- docker-compose.yml for services and nix-shell to run the code
- https://ghedam.at/15978/an-introduction-to-nix-shell