refactor: abstract NFS mount creation via custom options

modules/common/default.nix

@@ -2,6 +2,7 @@
   imports = [
     ./docker.nix
     ./monitoring.nix
+    ./nfs.nix
   ];
 
   config = {

modules/common/nfs.nix

@@ -0,0 +1,46 @@
+{ config, lib, ... }:
+
+{
+  options.homelab.nfsMounts = lib.mkOption {
+    type = lib.types.attrsOf (lib.types.submodule {
+      options = {
+        device = lib.mkOption {
+          type = lib.types.str;
+          description = "The NFS device, e.g. 192.168.0.11:/mnt/POOL/DATA";
+        };
+        readOnly = lib.mkOption {
+          type = lib.types.bool;
+          default = false;
+          description = "Whether to mount the NFS share read-only";
+        };
+        extraOptions = lib.mkOption {
+          type = lib.types.listOf lib.types.str;
+          default = [
+            "async"
+            "soft"
+            "timeo=100"
+            "retry=50"
+            "actimeo=1800"
+            "lookupcache=all"
+          ];
+          description = "Extra NFS mount options to append";
+        };
+      };
+    });
+    default = {};
+    description = "NFS mounts to automatically configure with standard homelab options";
+  };
+
+  config = {
+    fileSystems = lib.mapAttrs (path: cfg: {
+      device = cfg.device;
+      fsType = "nfs";
+      options = [
+        "nfsvers=4.2"
+        "nosuid"
+        "tcp"
+      ] ++ (if cfg.readOnly then [ "ro" ] else [ "rw" ])
+        ++ cfg.extraOptions;
+    }) config.homelab.nfsMounts;
+  };
+}