From 932838f73623afbe6c6ab1d1e31f03b79f0bcaf4 Mon Sep 17 00:00:00 2001
From: twoneis <sanjay29@sapura.de>
Date: Wed, 8 May 2024 19:20:06 +0200
Subject: [PATCH] initial attempt at impermance

---
 devices/ellaca/hardware-config.nix | 12 +++--
 flake.lock                         | 16 +++++++
 flake.nix                          |  4 ++
 modules/system/persist/default.nix |  8 ++++
 outputs.nix                        | 73 ++++++++++++++++--------------
 5 files changed, 74 insertions(+), 39 deletions(-)
 create mode 100644 modules/system/persist/default.nix

diff --git a/devices/ellaca/hardware-config.nix b/devices/ellaca/hardware-config.nix
index 570ec2a..5c882ae 100644
--- a/devices/ellaca/hardware-config.nix
+++ b/devices/ellaca/hardware-config.nix
@@ -6,10 +6,10 @@
       postDeviceCommands = lib.mkAfter ''
         mkdir /btrfs_tmp
         mount /dev/disk/by-uuid/b6e6bca7-1435-4b41-b174-8550eace7c32 /btrfs_tmp
-        if [[ -e /btrfs_tmp/root ]]; then
+        if [[ -e /btrfs_tmp/rootfs ]]; 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/$timestamp"
+            timestamp=$(date --date="@$(stat -c %Y /btrfs_tmp/rootfs)" "+%Y-%m-%-d_%H:%M:%S")
+            mv /btrfs_tmp/rootfs "/btrfs_tmp/old_roots/$timestamp"
         fi
 
         delete_subvolume_recursively() {
@@ -24,7 +24,7 @@
             delete_subvolume_recursively "$i"
         done
 
-        btrfs subvolume create /btrfs_tmp/root
+        btrfs subvolume create /btrfs_tmp/rootfs
         umount /btrfs_tmp
       '';
     };
@@ -35,6 +35,7 @@
   fileSystems = {
     "/boot" = {
       device = "/dev/disk/by-uuid/7ABC-9C12";
+      neededForBoot = true;
       fsType = "vfat";
     };
     "/" = {
@@ -45,16 +46,19 @@
     "/nix" = {
       device = "/dev/disk/by-uuid/b6e6bca7-1435-4b41-b174-8550eace7c32";
       fsType = "btrfs";
+      neededForBoot = true;
       options = [ "subvol=nix" "compress=zstd" "noatime" ];
     };
     "/persist" = {
       device = "/dev/disk/by-uuid/b6e6bca7-1435-4b41-b174-8550eace7c32";
       fsType = "btrfs";
+      neededForBoot = true;
       options = [ "subvol=persist" "compress=zstd" "noatime" ];
     };
     "/ext" = {
       device = "/dev/disk/by-uuid/3ed92a26-775a-4e39-ac1c-84b2822cd3dd";
       fsType = "btrfs";
+      neededForBoot = true;
       options = [ "subvol=ext" "compress=zstd" "noatime" ];
     };
   };
diff --git a/flake.lock b/flake.lock
index 34da028..f28c8cd 100644
--- a/flake.lock
+++ b/flake.lock
@@ -249,6 +249,21 @@
         "type": "github"
       }
     },
+    "impermanence": {
+      "locked": {
+        "lastModified": 1708968331,
+        "narHash": "sha256-VUXLaPusCBvwM3zhGbRIJVeYluh2uWuqtj4WirQ1L9Y=",
+        "owner": "nix-community",
+        "repo": "impermanence",
+        "rev": "a33ef102a02ce77d3e39c25197664b7a636f9c30",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "impermanence",
+        "type": "github"
+      }
+    },
     "niri": {
       "inputs": {
         "crate2nix": "crate2nix",
@@ -464,6 +479,7 @@
     "root": {
       "inputs": {
         "home-manager": "home-manager",
+        "impermanence": "impermanence",
         "niri": "niri",
         "nixos-hardware": "nixos-hardware",
         "nixpkgs": "nixpkgs_3",
diff --git a/flake.nix b/flake.nix
index cbc14ef..bbf34d3 100644
--- a/flake.nix
+++ b/flake.nix
@@ -21,6 +21,10 @@
       url = "github:sodiboo/niri-flake";
       inputs.nixpkgs.follows = "nixpkgs";
     };
+
+    impermanence = {
+      url = "github:nix-community/impermanence";
+    };
   };
 
   outputs = inputs: import ./outputs.nix inputs;
diff --git a/modules/system/persist/default.nix b/modules/system/persist/default.nix
new file mode 100644
index 0000000..997f429
--- /dev/null
+++ b/modules/system/persist/default.nix
@@ -0,0 +1,8 @@
+{ ... }: {
+  environment.persistence."/persist" = {
+    files = [
+      "/etc/shadow"
+      "/etc/passwd"
+    ];
+  };
+}
diff --git a/outputs.nix b/outputs.nix
index 10a7aab..4cca5e6 100644
--- a/outputs.nix
+++ b/outputs.nix
@@ -1,35 +1,5 @@
-{ nixpkgs, home-manager, nixos-hardware, nur, niri, ... }@inputs: {
-  nixosConfigurations = let
-
-    clientModules = [
-        ./modules/system
-        ./options.nix
-        niri.nixosModules.niri
-        home-manager.nixosModules.home-manager {
-          nixpkgs.overlays = [
-            nur.overlay
-          ];
-          home-manager = {
-            useGlobalPkgs = true;
-            useUserPackages = true;
-            users.twoneis = import ./modules/system/home;
-          };
-        }
-    ];
-
-    serverModules = [
-      ./modules/server
-      ./options.nix
-      home-manager.nixosModules.home-manager {
-        home-manager = {
-          useGlobalPkgs = true;
-          useUserPackages = true;
-          users.twoneis = import ./modules/server/home;
-        };
-      }
-    ];
-
-  in {
+{ nixpkgs, home-manager, nixos-hardware, nur, niri, impermanence, ... }@inputs: {
+  nixosConfigurations = {
     # AMD Ryzen 5600X
     # nvidia GeForce GTX 1060 (6GB)
     ellaca = nixpkgs.lib.nixosSystem {
@@ -39,7 +9,20 @@
       };
       modules = [
         ./devices/ellaca
-      ] ++ clientModules;
+        ./modules/system
+        ./modules/system/persist
+        ./options.nix
+        niri.nixosModules.niri
+        impermanence.nixosModules.impermanence
+        home-manager.nixosModules.home-manager {
+          nixpkgs.overlays = [ nur.overlay ];
+          home-manager = {
+            useGlobalPkgs = true;
+            useUserPackages = true;
+            users.twoneis = import ./modules/system/home;
+          };
+        }
+      ];
     };
 
     # Surface Pro 7 (i5 128GB)
@@ -50,8 +33,19 @@
       };
       modules = [
         ./devices/akarso
+        ./modules/system
+        ./options.nix
         nixos-hardware.nixosModules.microsoft-surface-pro-intel
-      ] ++ clientModules;
+        niri.nixosModules.niri
+        home-manager.nixosModules.home-manager {
+          nixpkgs.overlays = [ nur.overlay ];
+          home-manager = {
+            useGlobalPkgs = true;
+            useUserPackages = true;
+            users.twoneis = import ./modules/system/home;
+          };
+        }
+      ];
     };
 
     # Zotac Mini
@@ -63,7 +57,16 @@
       };
       modules = [
         ./devices/creosote
-      ] ++ serverModules;
+        ./modules/server
+        ./options.nix
+        home-manager.nixosModules.home-manager {
+          home-manager = {
+            useGlobalPkgs = true;
+            useUserPackages = true;
+            users.twoneis = import ./modules/server/home;
+          };
+        }
+      ];
     };
   };
 }