modules/systemd-extras: support chants

modules/systemd-extras/chant.nix

@@ -0,0 +1,19 @@
+{ lib, ... }:
+
+with lib;
+{
+  options.systemd.services = mkOption {
+    type = with types; attrsOf (submodule ({ config, name, ... }: {
+      options.chant = {
+        enable = mkEnableOption "listening for a waking chant";
+      };
+      config = lib.mkIf config.chant.enable {
+        serviceConfig = {
+          Type = "oneshot";
+          LoadCredential = [ "chantPayload:/run/chant/${name}" ];
+        };
+        environment.CHANT_PAYLOAD = "%d/chantPayload";
+      };
+    }));
+  };
+}

modules/systemd-extras/default.nix

@@ -2,5 +2,6 @@
   imports = [
     ./strict-mounts.nix
     ./distributed.nix
+    ./chant.nix
   ];
 }