feat(librechat): add ability to define config settings in nix way

modules/nixos/server/librechat/default.nix

@@ -13,6 +13,18 @@ in
     enable = lib.mkEnableOption "Whether to enable the LibreChat server.";
     openFirewall = lib.mkEnableOption "Whether to open the port in the firewall.";
 
+    settings = lib.mkOption {
+      type = lib.types.attrs;
+      default = { };
+      example = # nix
+        ''
+          {
+
+          }
+        '';
+      description = "A free-form attribute set that will be written to librechat.yaml.";
+    };
+
     path = lib.mkOption {
       type = lib.types.str;
       default = "/var/lib/librechat";
@@ -187,7 +199,14 @@ in
 
   };
 
-  config = lib.mkIf cfg.enable {
+  config = lib.mkIf cfg.enable (
+    let
+      configFile = pkgs.writeTextFile {
+        name = "librechat.yaml";
+        text = lib.generators.toYAML { } cfg.settings;
+      };
+    in
+    {
 
       assertions = [
         {
@@ -253,6 +272,7 @@ in
             export JWT_SECRET=$(${pkgs.systemd}/bin/systemd-creds cat JWT_SECRET_FILE)
             export JWT_REFRESH_SECRET=$(${pkgs.systemd}/bin/systemd-creds cat JWT_REFRESH_SECRET_FILE)
 
+            export CONFIG_PATH=${configFile}
             export HOST=${cfg.host}
             export PORT=${builtins.toString cfg.port}
             export MONGO_URI="${cfg.mongodbURI}"
@@ -271,5 +291,6 @@ in
         description = "LibreChat server user";
       };
       users.groups.librechat = lib.mkIf (cfg.user == "librechat") { };
-  };
+    }
+  );
 }

systems/x86_64-linux/apollo/default.nix

@@ -30,6 +30,9 @@
       openFirewall = true;
       host = "0.0.0.0";
       mongodbURI = "mongodb://apollo:27017";
+      settings = {
+        version = "1.0.8";
+      };
       auth = {
         allowEmailLogin = true;
         allowEmailRegistration = true;