Add impermanence implementation.

flake.lock

@@ -388,6 +388,21 @@
         "type": "github"
       }
     },
+    "impermanence-stable-nixos": {
+      "locked": {
+        "lastModified": 1737831083,
+        "narHash": "sha256-LJggUHbpyeDvNagTUrdhe/pRVp4pnS6wVKALS782gRI=",
+        "owner": "nix-community",
+        "repo": "impermanence",
+        "rev": "4b3e914cdf97a5b536a889e939fb2fd2b043a170",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "impermanence",
+        "type": "github"
+      }
+    },
     "nix-darwin": {
       "inputs": {
         "nixpkgs": [
@@ -616,6 +631,7 @@
         "disko-stable-nixos": "disko-stable-nixos",
         "home-manager-stable-nixos": "home-manager-stable-nixos",
         "hyprpanel-stable-nixos": "hyprpanel-stable-nixos",
+        "impermanence-stable-nixos": "impermanence-stable-nixos",
         "nix-flatpak-stable-nixos": "nix-flatpak-stable-nixos",
         "nixpkgs": "nixpkgs_2",
         "nixpkgs-stable-nixos": "nixpkgs-stable-nixos",

flake.nix

@@ -20,6 +20,10 @@
     hyprpanel-stable-nixos = {
       url = "github:Jas-SinghFSU/Hyprpanel";
     };
+
+    impermanence-stable-nixos = {
+      url = "github:nix-community/impermanence";
+    };
     
     nix-flatpak-stable-nixos = {
       url = "github:gmodena/nix-flatpak/?ref=latest";

nodes/hosts/common/configuration.nix

@@ -4,6 +4,7 @@
     inputs.nix-flatpak.nixosModules.nix-flatpak
     inputs.stylix.nixosModules.stylix
     inputs.home-manager.nixosModules.home-manager
+    inputs.impermanence.nixosModules.impermanence
     inputs.sops-nix.nixosModules.sops
     ./programs/emulation.nix
     ./programs/firefox.nix

nodes/hosts/lappy/configuration.nix

@@ -2,12 +2,13 @@
 # your system. Help is available in the configuration.nix(5) man page, on
 # https://search.nixos.org/options and in the NixOS manual (`nixos-help`).
 
-{ config, lib, pkgs, ... }:
+{ config, lib, pkgs, inputs, ... }:
 
 {
   imports =
     [ # Include the results of the hardware scan.
       ./hardware-configuration.nix
+      ./impermanence.nix
       ./programs/sof-firmware.nix
       # Not working yet.
       #./services/fprintd.nix

nodes/hosts/lappy/impermanence.nix

@@ -0,0 +1,41 @@
+{lib, ...}: {
+  #  Reset root subvolume on boot
+  boot.initrd.postResumeCommands = lib.mkAfter ''
+    mkdir /btrfs_tmp
+      mount /dev/mapper/cryptroot /btrfs_tmp # CONFIRM THIS IS CORRECT FROM findmnt
+      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
+  '';
+
+  # Use /persist as the persistence root, matching Disko's mountpoint
+  environment.persistence."/nix/persist" = {
+    hideMounts = true;
+    directories = [
+      "/etc" # System configuration (Keep this here for persistence via bind-mount)
+      "/var/spool" # Mail queues, cron jobs
+      "/srv" # Web server data, etc.
+      "/root"
+      "/home"
+    ];
+    files = [
+    ];
+  };
+}

nodes/hosts/nixy/impermanence.nix

@@ -0,0 +1,40 @@
+{lib, ...}: {
+  #  Reset root subvolume on boot
+  boot.initrd.postResumeCommands = lib.mkAfter ''
+    mkdir /btrfs_tmp
+      mount /dev/disk/by-uuid/77021dd1-9fa5-4e9f-9be2-ba943e6de77c /btrfs_tmp # CONFIRM THIS IS CORRECT FROM findmnt
+      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
+  '';
+
+  # Use /persist as the persistence root, matching Disko's mountpoint
+  environment.persistence."/nix/persist" = {
+    hideMounts = true;
+    directories = [
+      "/etc" # System configuration (Keep this here for persistence via bind-mount)
+      "/var/spool" # Mail queues, cron jobs
+      "/srv" # Web server data, etc.
+      "/root"
+    ];
+    files = [
+    ];
+  };
+}