devmon: New service

nixos/modules/module-list.nix

···
   ./services/misc/cpuminer-cryptonight.nix
   ./services/misc/cgminer.nix
   ./services/misc/confd.nix
+  ./services/misc/devmon.nix
   ./services/misc/dictd.nix
   ./services/misc/disnix.nix
   ./services/misc/docker-registry.nix

nixos/modules/services/misc/devmon.nix

···
+{ pkgs, config, lib, ... }:
+
+with lib;
+
+let
+  cfg = config.services.devmon;
+
+in {
+  options = {
+    services.devmon = {
+      enable = mkOption {
+        default = false;
+        description = ''
+          Whether to enable devmon, an automatic device mounting daemon.
+        '';
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.services.devmon = {
+      description = "devmon automatic device mounting daemon";
+      wantedBy = [ "multi-user.target" ];
+      path = [ pkgs.udevil ];
+      serviceConfig.ExecStart = "${pkgs.udevil}/bin/devmon";
+    };
+  };
+}