refactor(nixos): source navidrome mount paths from service

configs/nixos/guests/navidrome.nix

@@ -4,8 +4,7 @@
   ...
 }:
 let
-  dataDir = "/var/lib/navidrome";
-  libraryDir = "/music";
+  serviceConfig = config.containers.navidrome.config.modules.services.navidrome;
   envFile = "/run/secrets/navidrome.env";
   lastfmApiKeySecret = "services/navidrome/lastfm/api-key";
   lastfmSecretSecret = "services/navidrome/lastfm/secret";
@@ -44,13 +43,13 @@ in
       interior.modules.services.navidrome.enable = true;
 
       mounts = {
-        ${dataDir} = {
+        ${serviceConfig.dataDir} = {
           directory = config.guests.navidrome.dataPath;
           owner = config.registry."stable-uid".${config.networking.hostName}.navidrome;
           group = "storage";
           mode = "2770";
         };
-        ${libraryDir} = {
+        ${serviceConfig.libraryDir} = {
           directory = config.guests.navidrome.libraryPath;
           owner = "root";
           group = "storage";

configs/nixos/modules/services/navidrome.nix

@@ -6,6 +6,20 @@
 {
   options.modules.services.navidrome = {
     enable = lib.mkEnableOption "Navidrome";
+
+    dataDir = lib.mkOption {
+      type = lib.types.str;
+      default = "/var/lib/navidrome";
+      readOnly = true;
+      description = "Guest path where Navidrome stores its data folder.";
+    };
+
+    libraryDir = lib.mkOption {
+      type = lib.types.str;
+      default = "/music";
+      readOnly = true;
+      description = "Guest path where Navidrome reads its library folder.";
+    };
   };
 
   config = lib.mkMerge [
@@ -18,7 +32,7 @@
         isSystemUser = true;
         uid = config.registry."stable-uid".${config.networking.hostName}.navidrome;
         group = "storage";
-        home = "/var/lib/navidrome";
+        home = config.modules.services.navidrome.dataDir;
       };
 
       services.navidrome = {
@@ -30,8 +44,8 @@
         settings = {
           Address = "0.0.0.0";
           Port = 4533;
-          DataFolder = "/var/lib/navidrome";
-          MusicFolder = "/music";
+          DataFolder = config.modules.services.navidrome.dataDir;
+          MusicFolder = config.modules.services.navidrome.libraryDir;
           EnableSharing = true;
         };
       };