{ config, lib, inputs, ... }: let isBtrfs = config.fileSystems."/".fsType == "btrfs"; in { imports = [ inputs.impermanence.nixosModules.impermanence ]; fileSystems."/persist".neededForBoot = true; environment.persistence."/persist/system" = { hideMounts = true; directories = [ "/etc/nixos" "/var/log" "/var/lib/bluetooth" "/var/lib/nixos" "/var/lib/flatpak" "/var/lib/systemd/coredump" "/etc/NetworkManager/system-connections" { directory = "/var/lib/colord"; user = "colord"; group = "colord"; mode = "u=rwx,g=rx,o="; } ]; files = [ "/etc/machine-id" { file = "/var/keys/secret_file"; parentDirectory = {mode = "u=rwx,g=,o=";}; } ]; }; systemd.tmpfiles.rules = [ "d /persist/home/ 0777 root root -" # /persist/home created, owned by root #"d /persist/home/${username} 0700 ${username} users -" # /persist/home/ created, owned by that user #"d /persist/nixos-config 0700 ${username} users -" ]; programs.fuse.userAllowOther = true; boot.initrd.postDeviceCommands = lib.mkAfter ( if isBtrfs then '' mkdir /btrfs_tmp mount /dev/root_vg/root /btrfs_tmp if [[ -e /btrfs_tmp/root ]]; then mkdir -p /btrfs_tmp/old_roots timestamp=$(date --date="@$(stat -c %Y /btrfs_tmp/root)" "+%Y-%m-%-d_%H:%M:%S") mv /btrfs_tmp/root "/btrfs_tmp/old_roots/$timestamp" fi delete_subvolume_recursively() { IFS=$'\n' for i in $(btrfs subvolume list -o "$1" | cut -f 9- -d ' '); do delete_subvolume_recursively "/btrfs_tmp/$i" done btrfs subvolume delete "$1" } for i in $(find /btrfs_tmp/old_roots/ -maxdepth 1 -mtime +30); do delete_subvolume_recursively "$i" done btrfs subvolume create /btrfs_tmp/root umount /btrfs_tmp '' else '''' ); }