disko + impermanence pc

nixos/modules/disko/impermanence-disko.nix

@@ -0,0 +1,76 @@
+{
+  device ? throw "Set this to your disk device, e.g. /dev/sda",
+  ...
+}: {
+  disko.devices = {
+    disk.main = {
+      inherit device;
+      type = "disk";
+      content = {
+        type = "gpt";
+        partitions = {
+          boot = {
+            name = "boot";
+            size = "1M";
+            type = "EF02";
+          };
+          esp = {
+            name = "ESP";
+            size = "500M";
+            type = "EF00";
+            content = {
+              type = "filesystem";
+              format = "vfat";
+              mountpoint = "/boot";
+            };
+          };
+          swap = {
+            size = "32G";
+            content = {
+              type = "swap";
+              resumeDevice = true;
+            };
+          };
+          root = {
+            name = "root";
+            size = "100%";
+            content = {
+              type = "lvm_pv";
+              vg = "root_vg";
+            };
+          };
+        };
+      };
+    };
+    lvm_vg = {
+      root_vg = {
+        type = "lvm_vg";
+        lvs = {
+          root = {
+            size = "100%FREE";
+            content = {
+              type = "btrfs";
+              extraArgs = ["-f"];
+
+              subvolumes = {
+                "/root" = {
+                  mountpoint = "/";
+                };
+
+                "/persist" = {
+                  mountOptions = ["subvol=persist" "noatime"];
+                  mountpoint = "/persist";
+                };
+
+                "/nix" = {
+                  mountOptions = ["subvol=nix" "noatime"];
+                  mountpoint = "/nix";
+                };
+              };
+            };
+          };
+        };
+      };
+    };
+  };
+}

nixos/modules/impermanence/default.nix

@@ -0,0 +1,47 @@
+{ ... }:
+{
+
+    fileSystems."/persist".neededForBoot = true;
+    environment.persistence."/persist/system" = {
+    hideMounts = true;
+    directories = [
+	"/etc/nixos"
+	"/var/log"
+	"/var/lib/bluetooth"
+	"/var/lib/nixos"
+	"/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="; }; }
+	];
+    };
+
+    programs.fuse.userAllowOther = true;
+    boot.initrd.postDeviceCommands = lib.mkAfter ''
+    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
+  '';
+}

nixos/modules/impermanence/home.nix

@@ -0,0 +1,29 @@
+{ username, ... }:
+{
+    imports = [
+	inputs.impermanence.nixosModules.home-manager.impermanence
+    ];
+    home.persistence."/persist/home/${username}" = {
+    directories = [
+      "Downloads"
+      "Music"
+      "Pictures"
+      "Documents"
+      "Videos"
+      "VirtualBox VMs"
+      ".gnupg"
+      ".ssh"
+      ".nixops"
+      ".local/share/keyrings"
+      ".local/share/direnv"
+      {
+        directory = ".local/share/Steam";
+        method = "symlink";
+      }
+    ];
+    files = [
+      ".screenrc"
+    ];
+    allowOther = true;
+  };
+}