refactor: moved nixos modules to dendrite pattern

modules/nixos/programs/network_storage/nfs.nix

@@ -0,0 +1,109 @@
+{...}: {
+  flake.nixosModules.network-storage-nfs = {
+    config,
+    lib,
+    ...
+  }: {
+    options = {
+      host.network_storage.nfs = {
+        enable = lib.mkEnableOption "is this server going to export network storage as nfs shares";
+        port = lib.mkOption {
+          type = lib.types.int;
+          default = 2049;
+          description = "port that nfs will run on";
+        };
+        directories = lib.mkOption {
+          type = lib.types.listOf (
+            lib.types.enum (
+              builtins.map (
+                directory: directory.folder
+              )
+              config.host.network_storage.directories
+            )
+          );
+          description = "list of exported directories to be exported via nfs";
+        };
+      };
+    };
+    config = lib.mkMerge [
+      {
+        assertions = [
+          {
+            assertion = !(config.host.network_storage.nfs.enable && !config.host.network_storage.enable);
+            message = "nfs cant be enabled with network storage disabled";
+          }
+        ];
+      }
+      (
+        lib.mkIf (config.host.network_storage.nfs.enable && config.host.network_storage.enable) {
+          services.nfs = {
+            settings = {
+              nfsd = {
+                threads = 32;
+                port = config.host.network_storage.nfs.port;
+              };
+            };
+            server = {
+              enable = true;
+
+              lockdPort = 4001;
+              mountdPort = 4002;
+              statdPort = 4000;
+
+              exports = lib.strings.concatLines (
+                [
+                  "${config.host.network_storage.export_directory} 100.64.0.0/10(rw,fsid=0,no_subtree_check)"
+                ]
+                ++ (
+                  lib.lists.imap0 (
+                    i: directory: let
+                      createOptions = fsid: "(rw,fsid=${toString fsid},nohide,insecure,no_subtree_check)";
+                      addresses = [
+                        # loopback
+                        "127.0.0.1"
+                        "::1"
+                        # tailscale
+                        "100.64.0.0/10"
+                        "fd7a:115c:a1e0::/48"
+                      ];
+                      options = lib.strings.concatStrings (
+                        lib.strings.intersperse " " (
+                          lib.lists.imap0 (index: address: "${address}${createOptions (1 + (i * (builtins.length addresses)) + index)}") addresses
+                        )
+                      );
+                    in "${directory._directory} ${options}"
+                  )
+                  (
+                    builtins.filter (
+                      directory: lib.lists.any (target: target == directory.folder) config.host.network_storage.nfs.directories
+                    )
+                    config.host.network_storage.directories
+                  )
+                )
+              );
+            };
+          };
+          networking.firewall = let
+            ports = [
+              111
+              config.host.network_storage.nfs.port
+              config.services.nfs.server.lockdPort
+              config.services.nfs.server.mountdPort
+              config.services.nfs.server.statdPort
+              20048
+            ];
+          in {
+            # Allow NFS on Tailscale interface
+            interfaces.${config.services.tailscale.interfaceName} = {
+              allowedTCPPorts = ports;
+              allowedUDPPorts = ports;
+            };
+            # Allow NFS on local network (assuming default interface)
+            allowedTCPPorts = ports;
+            allowedUDPPorts = ports;
+          };
+        }
+      )
+    ];
+  };
+}