nixos/modules/services/networking/networkd-dispatcher.nix

   1 { config, lib, pkgs, ... }:
   2
   3 with lib;
   4
   5 let
   6
   7   cfg = config.services.networkd-dispatcher;
   8
   9 in {
  10
  11   options = {
  12     services.networkd-dispatcher = {
  13
  14       enable = mkEnableOption ''
  15         Networkd-dispatcher service for systemd-networkd connection status
  16         change. See [upstream instructions](https://gitlab.com/craftyguy/networkd-dispatcher)
  17         for usage
  18       '';
  19
  20       rules = mkOption {
  21         default = {};
  22         example = lib.literalExpression ''
  23           { "restart-tor" = {
  24               onState = ["routable" "off"];
  25               script = '''
  26                 #!''${pkgs.runtimeShell}
  27                 if [[ $IFACE == "wlan0" && $AdministrativeState == "configured" ]]; then
  28                   echo "Restarting Tor ..."
  29                   systemctl restart tor
  30                 fi
  31                 exit 0
  32               ''';
  33             };
  34           };
  35         '';
  36         description = ''
  37           Declarative configuration of networkd-dispatcher rules. See
  38           [upstream instructions](https://gitlab.com/craftyguy/networkd-dispatcher)
  39           for an introduction and example scripts.
  40         '';
  41         type = types.attrsOf (types.submodule {
  42           options = {
  43             onState = mkOption {
  44               type = types.listOf (types.enum [
  45                 "routable" "dormant" "no-carrier" "off" "carrier" "degraded"
  46                 "configuring" "configured"
  47               ]);
  48               default = null;
  49               description = ''
  50                 List of names of the systemd-networkd operational states which
  51                 should trigger the script. See <https://www.freedesktop.org/software/systemd/man/networkctl.html>
  52                 for a description of the specific state type.
  53               '';
  54             };
  55             script = mkOption {
  56               type = types.lines;
  57               description = ''
  58                 Shell commands executed on specified operational states.
  59               '';
  60             };
  61           };
  62         });
  63       };
  64
  65     };
  66   };
  67
  68   config = mkIf cfg.enable {
  69
  70     systemd = {
  71       packages = [ pkgs.networkd-dispatcher ];
  72       services.networkd-dispatcher = {
  73         wantedBy = [ "multi-user.target" ];
  74         # Override existing ExecStart definition
  75         serviceConfig.ExecStart = let
  76           scriptDir = pkgs.symlinkJoin {
  77             name = "networkd-dispatcher-script-dir";
  78             paths = lib.mapAttrsToList (name: cfg:
  79               (map(state:
  80                 pkgs.writeTextFile {
  81                   inherit name;
  82                   text = cfg.script;
  83                   destination = "/${state}.d/${name}";
  84                   executable = true;
  85                 }
  86               ) cfg.onState)
  87             ) cfg.rules;
  88           };
  89         in [
  90           ""
  91           "${pkgs.networkd-dispatcher}/bin/networkd-dispatcher -v --script-dir ${scriptDir} $networkd_dispatcher_args"
  92         ];
  93       };
  94     };
  95
  96   };
  97 }
  98