Temporarily access NixOS with encrypted LUKS from Ubuntu Live

Setup

• Boot Ubuntu Live as usual
• Change keyboard layout with setxkbmap <lang>
• Install useful packages with sudo apt install vim nix-bin

Open crypt device

• Idenitify LUKS device with lsblk --fs. Look for crypto_LUKS:

  nvme0n1
  ├─nvme0n1p1   vfat        FAT32
  └─nvme0n1p2   crypto_LUKS 2

• Open encrypted device with cryptsetup luksOpen /dev/<root partition (sda2 or similar)> secure
• Check sucessfull open with lslbk. You should now see the crypt partition(s):

  nvme0n1       259:0    0 476.9G  0 disk
  ├─nvme0n1p1   259:1    0   549M  0 part
  └─nvme0n1p2   259:2    0 476.4G  0 part
  └─enc-pv    253:0    0 476.4G  0 crypt
    ├─vg-swap 253:1    0    16G  0 lvm
    └─vg-root 253:2    0 460.4G  0 lvm

Mount partitions

• lvchange -a y /dev/vg/swap
• lvchange -a y /dev/vg/root
• mount /dev/vg/root /mnt
• mount /dev/<boot partition (sda1 or similar)> /mnt/boot
• swapon /dev/vg/swap

Temporarily access NixOS

• Access with nixos-enter
• Optional:
  • Add additional channel if needed
    nix-channel --add https://github.com/NixOS/mobile-nixos/archive/refs/heads/master.tar.gz mobile-nixos
  • Update channels nix-channel --update
• Change config
• Rebuild system nixos-rebuild boot