dotfiles/modules/darling-erasure/default.nix

71 lines
2.6 KiB
Nix

{ config, lib, pkgs, ... }:
{
environment.etc = {
nixos.source = "/persist/etc/nixos";
"NetworkManager/system-connections".source =
"/persist/etc/NetworkManager/system-connections";
adjtime.source = "/persist/etc/adjtime";
NIXOS.source = "/persist/etc/NIXOS";
machine-id.source = "/persist/etc/machine-id";
"ssh/ssh_host_ed25519_key".source = "/persist/etc/ssh/ssh_host_ed25519_key";
"ssh/ssh_host_ed25519_key.pub".source =
"/persist/etc/ssh/ssh_host_ed25519_key.pub";
"ssh/ssh_host_rsa_key".source = "/persist/etc/ssh/ssh_host_rsa_key";
"ssh/ssh_host_rsa_key.pub".source = "/persist/etc/ssh/ssh_host_rsa_key.pub";
shadow.source = "/persist/etc/shadow";
};
systemd.tmpfiles.rules = [
"L /var/lib/NetworkManager/secret_key - - - - /persist/var/lib/NetworkManager/secret_key"
"L /var/lib/NetworkManager/seen-bssids - - - - /persist/var/lib/NetworkManager/seen-bssids"
"L /var/lib/NetworkManager/timestamps - - - - /persist/var/lib/NetworkManager/timestamps"
];
security.sudo.extraConfig = ''
# rollback results in sudo lectures after each reboot
Defaults lecture = never
'';
# Note `lib.mkBefore` is used instead of `lib.mkAfter` here.
boot.initrd.postDeviceCommands = pkgs.lib.mkBefore ''
mkdir -p /mnt
# We first mount the btrfs root to /mnt
# so we can manipulate btrfs subvolumes.
mount -o subvol=/ /dev/mapper/enc /mnt
# While we're tempted to just delete /root and create
# a new snapshot from /root-blank, /root is already
# populated at this point with a number of subvolumes,
# which makes `btrfs subvolume delete` fail.
# So, we remove them first.
#
# /root contains subvolumes:
# - /root/var/lib/portables
# - /root/var/lib/machines
#
# I suspect these are related to systemd-nspawn, but
# since I don't use it I'm not 100% sure.
# Anyhow, deleting these subvolumes hasn't resulted
# in any issues so far, except for fairly
# benign-looking errors from systemd-tmpfiles.
btrfs subvolume list -o /mnt/root |
cut -f9 -d' ' |
while read subvolume; do
echo "deleting /$subvolume subvolume..."
btrfs subvolume delete "/mnt/$subvolume"
done &&
echo "deleting /root subvolume..." &&
btrfs subvolume delete /mnt/root
echo "restoring blank /root subvolume..."
btrfs subvolume snapshot /mnt/root-blank /mnt/root
# Once we're done rolling back to a blank snapshot,
# we can unmount /mnt and continue on the boot process.
umount /mnt
'';
# In case one forgets to move /etc/shadow to /persist
users.users.moritz.initialPassword = "password";
}