Merge pull request #46144 from dasJ/nullidentdmod-module

nixos/nullidentdmod: Init

nixos/modules/module-list.nix

@@ -556,6 +556,7 @@
   ./services/networking/nsd.nix
   ./services/networking/ntopng.nix
   ./services/networking/ntpd.nix
+  ./services/networking/nullidentdmod.nix
   ./services/networking/nylon.nix
   ./services/networking/ocserv.nix
   ./services/networking/oidentd.nix

nixos/modules/services/networking/nullidentdmod.nix

@@ -0,0 +1,34 @@
+{ config, lib, pkgs, ... }: with lib; let
+  cfg = config.services.nullidentdmod;
+
+in {
+  options.services.nullidentdmod = with types; {
+    enable = mkEnableOption "Enable the nullidentdmod identd daemon";
+
+    userid = mkOption {
+      type = nullOr str;
+      description = "User ID to return. Set to null to return a random string each time.";
+      default = null;
+      example = "alice";
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.sockets.nullidentdmod = {
+      description = "Socket for identd (NullidentdMod)";
+      listenStreams = [ "113" ];
+      socketConfig.Accept = true;
+      wantedBy = [ "sockets.target" ];
+    };
+
+    systemd.services."nullidentdmod@" = {
+      description = "NullidentdMod service";
+      serviceConfig = {
+        DynamicUser = true;
+        ExecStart = "${pkgs.nullidentdmod}/bin/nullidentdmod${optionalString (cfg.userid != null) " ${cfg.userid}"}";
+        StandardInput = "socket";
+        StandardOutput = "socket";
+      };
+    };
+  };
+}