implement route as module-based-service

modules/network/route.nix

@@ -0,0 +1,20 @@
+{
+  liminix
+, ifwait
+, serviceFns
+, lib
+}:
+{ target, via, interface ? null, metric }:
+let
+  inherit (liminix.services) oneshot;
+  with_dev = if interface != null then "dev $(input ${interface} ifname)" else "";
+in oneshot {
+  name = "route-${target}-${builtins.substring 0 12 (builtins.hashString "sha256" "${via}-${if interface!=null then interface.name else ""}")}";
+  up = ''
+    ip route add ${target} via ${via} metric ${toString metric} ${with_dev}
+  '';
+  down = ''
+    ip route del ${target} via ${via} ${with_dev}
+  '';
+  dependencies = [] ++ lib.optional (interface != null) interface;
+}