implement ifwait trigger service and use in bridge

should we convert all ifwait uses to this trigger too? seems
reasonable

modules/bridge/default.nix

@@ -14,6 +14,8 @@ let
   inherit (pkgs) liminix;
 in
 {
+  imports = [ ../ifwait ];
+
   options = {
     system.service.bridge = {
       primary = mkOption { type = liminix.lib.types.serviceDefn; };
@@ -27,7 +29,7 @@ in
         description = "bridge interface name to create";
       };
     };
-    members = liminix.callService ./members.nix {
+    members = config.system.callService ./members.nix {
       primary = mkOption {
         type = liminix.lib.types.interface;
         description = "primary bridge interface";
@@ -47,5 +49,5 @@ in
     # a better way to test for the existence of vlan config:
     # maybe the module should set an `enabled` attribute?
     BRIDGE_VLAN_FILTERING = "y";
-  };    
+  };
 }

modules/bridge/members.nix

@@ -2,6 +2,7 @@
   liminix
 , ifwait
 , lib
+, svc
 }:
 { members, primary } :
 
@@ -10,14 +11,20 @@ let
   inherit (liminix.services) bundle oneshot;
   inherit (lib) mkOption types;
   addif = member :
-    oneshot {
-      name = "${primary.name}.member.${member.name}";
-      up = ''
-        dev=$(output ${member} ifname)
-        ${ifwait}/bin/ifwait $dev running && ip link set dev $dev master $(output ${primary} ifname)
-      '';
-      down = "ip link set dev $(output ${member} ifname) nomaster";
+    # how do we get sight of services from here? maybe we need to
+    # implement ifwait as a regualr derivation instead of a
+    # servicedefinition
+    svc.ifwait.build {
+      state = "running";
+      interface = member;
       dependencies = [ primary member ];
+      service = oneshot {
+        name = "${primary.name}.member.${member.name}";
+        up = ''
+          ip link set dev $(output ${member} ifname) master $(output ${primary} ifname)
+        '';
+        down = "ip link set dev $(output ${member} ifname) nomaster";
+      };
     };
 in bundle {
   name = "${primary.name}.members";