refactor(machine/root): centralise root drive cfg

nix/modules/machine/root.nix

@@ -0,0 +1,100 @@
+{
+  config,
+  lib,
+  inputs,
+  ...
+}:
+let
+  inherit (lib.modules) mkMerge mkIf mkAfter;
+in
+{
+  flake.modules.nixos.default =
+    { hostName, ... }:
+    let
+      inherit (config.flake.manifest.hosts.nixos.${hostName}.machine) root;
+    in
+    {
+      imports = [ inputs.disko.nixosModules.disko ];
+      config = mkMerge [
+        {
+          # BTRFS - may add more later on
+          boot.initrd.kernelModules = [ "dm-snapshot" ];
+          disko.devices.disk.main = {
+            device = root.drive;
+            content.type = "gpt";
+            content.partitions = {
+              boot = {
+                name = "boot";
+                size = "1M";
+                type = "EF02";
+              };
+              esp = {
+                name = "ESP";
+                size = "500M";
+                type = "EF00";
+                content = {
+                  type = "filesystem";
+                  format = "vfat";
+                  mountpoint = "/boot";
+                };
+              };
+              swap = {
+                size = "4G";
+                content = {
+                  type = "swap";
+                  resumeDevice = true;
+                };
+              };
+              root = {
+                name = "root";
+                size = "100%";
+                content = {
+                  type = "lvm_pv";
+                  vg = "root_vg";
+                };
+              };
+            };
+          };
+
+          disko.devices.lvm_vg.root_vg = {
+            type = "lvm_vg";
+            lvs.root = {
+              size = "100%FREE";
+              content = {
+                type = "btrfs";
+                extraArgs = [ "-f" ];
+                subvolumes = {
+                  "/root".mountpoint = "/";
+                  "/persist" = {
+                    mountpoint = "/persist";
+                    mountOptions = [
+                      "subvol=persist"
+                      "noatime"
+                    ];
+                  };
+                  "/nix" = {
+                    mountpoint = "/nix";
+                    mountOptions = [
+                      "subvol=nix"
+                      "noatime"
+                    ];
+                  };
+                };
+              };
+            };
+          };
+        }
+        # Ephemeral by default - assumes btrfs
+        (mkIf (config.flake.manifest.hosts.nixos.${hostName}.machine.root.ephemeral or true) {
+          boot.initrd.postDeviceCommands = mkAfter ''
+            mkdir /btrfs_tmp
+            mount /dev/root_vg/root /btrfs_tmp
+
+            if [[ -e /btrfs_tmp/root ]]; then
+              btrfs subvolume delete "/btrfs_tmp/root"
+            fi
+          '';
+        })
+      ];
+    };
+}

nix/modules/machine/root/drive.nix

@@ -1,75 +0,0 @@
-{ config, inputs, ... }:
-{
-  flake.modules.nixos.default =
-    { hostName, ... }:
-    {
-      imports = [ inputs.disko.nixosModules.disko ];
-      boot.initrd.kernelModules = [ "dm-snapshot" ];
-      # BTRFS - may add more later on
-      disko.devices.disk.main = {
-        device = config.flake.manifest.hosts.nixos.${hostName}.machine.root.drive;
-        type = "disk";
-        content.type = "gpt";
-        content.partitions = {
-          boot = {
-            name = "boot";
-            size = "1M";
-            type = "EF02";
-          };
-          esp = {
-            name = "ESP";
-            size = "500M";
-            type = "EF00";
-            content = {
-              type = "filesystem";
-              format = "vfat";
-              mountpoint = "/boot";
-            };
-          };
-          swap = {
-            size = "4G";
-            content = {
-              type = "swap";
-              resumeDevice = true;
-            };
-          };
-          root = {
-            name = "root";
-            size = "100%";
-            content = {
-              type = "lvm_pv";
-              vg = "root_vg";
-            };
-          };
-        };
-      };
-
-      disko.devices.lvm_vg.root_vg = {
-        type = "lvm_vg";
-        lvs.root = {
-          size = "100%FREE";
-          content = {
-            type = "btrfs";
-            extraArgs = [ "-f" ];
-            subvolumes = {
-              "/root".mountpoint = "/";
-              "/persist" = {
-                mountpoint = "/persist";
-                mountOptions = [
-                  "subvol=persist"
-                  "noatime"
-                ];
-              };
-              "/nix" = {
-                mountpoint = "/nix";
-                mountOptions = [
-                  "subvol=nix"
-                  "noatime"
-                ];
-              };
-            };
-          };
-        };
-      };
-    };
-}

nix/modules/machine/root/ephemeral.nix

@@ -1,23 +0,0 @@
-{ config, lib, ... }:
-let
-  inherit (lib.modules) mkMerge mkIf mkAfter;
-in
-{
-  flake.modules.nixos.default =
-    { hostName, ... }:
-    {
-      config = mkMerge [
-        # Ephemeral by default - assumes btrfs
-        (mkIf (config.flake.manifest.hosts.nixos.${hostName}.machine.root.ephemeral or true) {
-          boot.initrd.postDeviceCommands = mkAfter ''
-            mkdir /btrfs_tmp
-            mount /dev/root_vg/root /btrfs_tmp
-
-            if [[ -e /btrfs_tmp/root ]]; then
-              btrfs subvolume delete "/btrfs_tmp/root"
-            fi
-          '';
-        })
-      ];
-    };
-}