Nixos with flakes

Devices

Virtual machine: 📦 Linux: 🐧 NixOS: ❄️ Desktop: 🖥️ Laptop: 💻️

Directory structure

|-- home                    <-- home-manager configuration for each user
|   `-- eragon              <-- home-manager for user eragon
|       |-- common          <-- default configuration for cli
|       |-- features
|       |   |-- cli         <-- configuration for all cli related tools
|       |   |-- desktop     <-- user configuration for desktop tools
|       |   |   |-- common
|       |   |   |-- gnome
|       |   |   |-- sway
|       |   `-- nvim        <-- configuration for nvim (from the repo kickstart.nvim)
|       |-- ash.nix         <-- home-manager for host ash
|       |-- ssh.pub
|       `-- vm1.nix         <-- home-manager for host vm1
|
|-- hosts                   <-- all configuration on host level
|   |-- common
|   |   |-- base            <-- base configuration for all hosts
|   |   |-- disko           <-- disko configs to set disk partitions on nix-anywhere install
|   |   |-- optional        <-- optional configurations (like gnome, sddm, gdm, ...) on system level
|   |   `-- users           <-- configuration for each user (to call home-manager)
|   |       `-- eragon
|   |-- ash                 <-- configuration for the host ash
|   |   |-- default.nix
|   |   `-- hardware-configuration.nix
|   |-- vm1                 <-- configuration for the host vm1
|
|-- modules                 <-- modules for home-manager and nixos
|   |-- home-manager
|   `-- nixos
|
|-- overlays/               <-- Overlays to modify pkgs
|
|-- pkgs                    <-- Custom packages
|   `-- wallpapers          <-- Package for custom wallpapers
|
|-- default.nix             <-- Nix dev file to be able to run the flake
|-- deploy.sh               <-- Shell file to run the flake and update the system
|-- flake.lock              <-- Version lock for the flake
|-- flake.nix               <-- Nix file for the flake
`-- README.md               <-- This README

Add a new host

1. Make a new folder under ´./hosts´
2. Copy the harware config and adjust
3. Create a new file under /home/username

Desktops

• desktops can be changed in ´hosts/{hostname}/default.nix´

Usefull commands

Cleaning up space

nix-store --gc
nix-store --gc --print-roots | egrep -v "^(/nix/var|/run/\w+-system|\{memory|/proc)"

sudo nix-collect-garbage --delete-older-than 20d

Installation with minimal iso and nixos-anywhere

Prep

[!IMPORTANT] code below uses vm1 as the example host

1. Generate a ssh key for the new host

or get it from a vault (see nixos-anywhere vaults)

ssh-keygen -o -a 100 -t ed25519 -f ~/.ssh/id_ed25519 -C root@vm1

2. Put the ssh key in the following folder structure on the host

`"$temp/etc/ssh/ssh_host_ed25519_key"´

3. Set the correct permissions for the host

# Set the correct permissions so sshd will accept the key
chmod 600 "$temp/etc/ssh/ssh_host_ed25519_key"

Instalation

1. Boot live installer
2. Check disks and adapt the config
3. Set nixos password and get IP
4. Test configuration

nix run github:nix-community/nixos-anywhere -- --flake .#vm1 --vm-test

5. Run the install commando from an other device with nix (change Ip and hostname)

nix run github:nix-community/nixos-anywhere -- --extra-files "$temp" --flake .#vm1 nixos@ip

(without extra temp files)

nix run github:nix-community/nixos-anywhere -- --extra-files "$temp" --flake .#vm1 nixos@ip

RAID

As btrfs raid 10 is not supported from just disko run the following command after running btrfs

add disk /dev/sdd to /data

btrfs device add /dev/sdd /data

and after you have added all the disks run

btrfs balance start -v -dconvert=raid10,soft /data

Build iso and attach shell to it

• select another user if you want to test the ssh connection

QEMU_NET_OPTS="hostfwd=tcp::2222-:22" nix --impure run github:nix-community/nixos-anywhere -- --flake .#vm1 --vm-test

ssh -p 2222 eragon@localhost

Create password hash

To create a password hash run the following command

mkpasswd -m sha-512

Deploy on current host

• run following command on a nixos host:

nix-shell https://github.com/jarneamerlinck/nix-config/tarball/main

Troubleshooting

RAID root disk is gone

mount -o degraded,usebackuproot /data

Quick tips

Snapper on btrfs

Snapper is used for snapshotting and recovery.

see snapper for more info.