Nix Configuration

Minimal Installation

Based on https://nixos.org/manual/nixos/stable/#sec-installation-manual

sudo -i

Configure wifi

sudo systemctl start wpa_supplicant

wpa_cli
0
set_network 0 ssid "network"
OK
set_network 0 psk "password"
OK
enable_network 0
OK
quit

UEFI (GPT)

parted /dev/disk1 -- mklabel gpt
parted /dev/disk1 -- mkpart root ext4 512MB -8GB
parted /dev/disk1 -- mkpart swap linux-swap -8GB 100%
parted /dev/disk1 -- mkpart ESP fat32 1MB 512MB
parted /dev/disk1 -- set 3 esp on

(Optional) LUKS Setup

cryptsetup luksFormat /dev/disk1part1
cryptsetup luksOpen /dev/disk1part1 crypted
mkfs.ext4 /dev/mapper/crypted

Formatting

mkfs.ext4 -L nixos /dev/disk1part1 # Skip when using LUKS
mkswap -L swap /dev/disk1part2
mkfs.fat -F 32 -n boot /dev/disk1part3

Installing

mount /dev/disk/by-label/nixos /mnt # No LUKS
mount /dev/mapper/crypted /mnt # LUKS
mkdir -p /mnt/boot
mount -o umask=077 /dev/disk/by-label/boot /mnt/boot
swapon /dev/disk1part2

nixos-generate-config --root /mnt

Configure hostname, enable networking.networkmanager.enable, set user with package git and save.

nano /mnt/etc/nixos/configuration.nix

Install nixos

nixos-install

Set user password and reboot.

nixos-enter --root /mnt -c 'passwd user'
reboot

Setup

Assuming the repo is cloned (use nmtui for wifi).

cd develop/nix_config

Copy the hardware configuration to the host directory.

cp /etc/nixos/hardware-configuration.nix hosts/my-host

Wipe the old nixos configuration.

sudo rm -rf /etc/nixos/*

Symlink new configuration.

sudo ln -s $(pwd)/flake.nix /etc/nixos/flake.nix

Lastly, rebuild the nixos configuration and reboot.

sudo nixos-rebuild switch .#my-host
reboot

Post-install Secrets Configuration

Update password manager.

unison
keepassxc ~/Desktop/$USER.kdbx

Create and add new ssh key.

ssh-keygen
cat ~/.ssh/id_*.pub >> modules/nixos/authorized_keys
git commit -m "conf: add authorized public key" --no-gpg-sign

Then copy GPG from other system, you may need to reboot the system.

ssh other@hostname 'gpg --export-secret-keys -a "$(gpg -K | rg -o "[A-F0-9]{40}")"' | gpg --import
gpg --edit-key "$(gpg -K | rg -o "[A-F0-9]{40}")"
seahorse

Mounting drives

List drives

lsblk -f -o NAME,UUID,FSTYPE,SIZE

Set drive to mount

nvim hosts/new-host/hardware-configuration.nix

fileSystems."/mnt/hdd" =
  { device = "/dev/disk/by-uuid/uuid";
    fsType = "ext4";
  };

Troubleshooting

Zed editor Java JDTLS oneshot error

rm -r /tmp/jdtls-*

Figured out through

strace -f -o trace.log zeditor --foreground .
cat trace.log | rg jdtls

NixOS Anywhere

nix run github:nix-community/nixos-anywhere -- \
  --generate-hardware-config nixos-generate-config ./<configuration-name>/hardware-configuration.nix --no-substitute-on-destination \
  --flake .#<configuration-name> root@<ip address>

ssh user@<ip address>
ssh root@<ip address>
passwd user

  services.openssh = {
    enable = true;
    ports = [ 22 ];
    settings = {
      # PasswordAuthentication = false;
      # PermitRootLogin = "no";
      # UsePAM = false;
      # KbdInteractiveAuthentication = false;
    };
  };

nixos-rebuild --target-host user@ip-address --use-remote-sudo switch --flake .#<configuration-name>

VMs

Resize disk

Host

sudo qemu-img resize /path/to/qemu/<vm-name>.qcow2 +10G

Guest

lsblk
sudo parted /dev/vda
> print
> resizepart 1 10GB
> quit
sudo resize2fs /dev/vda1
df -h

Troubleshooting

After updating firmware

Error: Unable to find 'efi' firmware that is compatible with the current version

Update the firmware path in the VM configuration.

Find paths

fd secure-code /nix/store/
/nix/store/ddf1vssb23g4jbdivhfgwi0iaimpz7my-qemu-9.1.3/share/qemu/edk2-x86_64-secure-code.fd
/nix/store/ddf1vssb23g4jbdivhfgwi0iaimpz7my-qemu-9.1.3/share/qemu/edk2-i386-secure-code.fd
/nix/store/sq4s9m7n5nj6asjddbbr46wnxp42sxrg-qemu-9.1.2/share/qemu/edk2-x86_64-secure-code.fd
/nix/store/sq4s9m7n5nj6asjddbbr46wnxp42sxrg-qemu-9.1.2/share/qemu/edk2-i386-secure-code.fd
fd vars.fd /nix/store
/nix/store/ddf1vssb23g4jbdivhfgwi0iaimpz7my-qemu-9.1.3/share/qemu/edk2-arm-vars.fd
/nix/store/ddf1vssb23g4jbdivhfgwi0iaimpz7my-qemu-9.1.3/share/qemu/edk2-riscv-vars.fd
/nix/store/ddf1vssb23g4jbdivhfgwi0iaimpz7my-qemu-9.1.3/share/qemu/edk2-i386-vars.fd
/nix/store/sq4s9m7n5nj6asjddbbr46wnxp42sxrg-qemu-9.1.2/share/qemu/edk2-arm-vars.fd
/nix/store/sq4s9m7n5nj6asjddbbr46wnxp42sxrg-qemu-9.1.2/share/qemu/edk2-riscv-vars.fd
/nix/store/sq4s9m7n5nj6asjddbbr46wnxp42sxrg-qemu-9.1.2/share/qemu/edk2-i386-vars.fd