refactor(reverse-proxy): use route registry

modules/reverse-proxy.nix

@@ -1,10 +1,33 @@
-{ config, lib, my, ... }:
+{
+  config,
+  lib,
+  my,
+  ...
+}@args:
 let
   cfg = config.modules.reverse-proxy;
-  inherit (my) reverseProxyRoutes;
+  registry = args.registry or config.registry;
 
-  enabledRoutes = lib.filterAttrs (_: route: route.enable) cfg.routes;
-  routesByHost = lib.groupBy (route: route.host) (lib.attrValues enabledRoutes);
+  routeWithBackend = hostName: routeName: route:
+    let
+      facts = my.registry.lookup registry hostName routeName;
+    in
+    if route.backend != null then
+      route
+    else if facts ? address && route.port != null then
+      route // { backend = "${route.scheme}://${facts.address}:${toString route.port}"; }
+    else
+      route;
+
+  allRoutes = lib.concatLists (
+    lib.mapAttrsToList (
+      hostName: routes:
+      lib.mapAttrsToList (routeName: route: routeWithBackend hostName routeName route) routes
+    ) registry.route
+  );
+
+  enabledRoutes = builtins.filter (route: route.enable) allRoutes;
+  routesByHost = lib.groupBy (route: route.host) enabledRoutes;
 
   rootRoutesByHost = lib.mapAttrs (
     host: routes:
@@ -46,27 +69,22 @@ in
   options.modules.reverse-proxy = {
     enable = lib.mkEnableOption "the Nginx reverse proxy route realizer";
 
-    routes = lib.mkOption {
-      type = lib.types.attrsOf reverseProxyRoutes.routeType;
-      default = { };
-      description = "Reverse-proxy route declarations keyed by stable route name.";
-    };
   };
 
   config = lib.mkIf cfg.enable {
     assertions =
       lib.mapAttrsToList (host: rootRoute: {
         assertion = rootRoute != null;
-        message = "modules.reverse-proxy.routes for ${host} must include a primary / route.";
+        message = "registry.route entries for ${host} must include a primary / route.";
       }) rootRoutesByHost
       ++ lib.mapAttrsToList (host: routes: {
         assertion = !hasDuplicatePaths routes;
-        message = "modules.reverse-proxy.routes for ${host} must not declare the same path more than once.";
+        message = "registry.route entries for ${host} must not declare the same path more than once.";
       }) routesByHost
       ++ map (route: {
         assertion = !hasUnresolvedBackend route;
-        message = "modules.reverse-proxy.routes for ${route.host}${route.path} must resolve to a backend URL before actualization.";
-      }) (builtins.filter hasUnresolvedBackend (lib.attrValues enabledRoutes));
+        message = "registry.route entry for ${route.host}${route.path} must resolve to a backend URL before actualization.";
+      }) (builtins.filter hasUnresolvedBackend enabledRoutes);
 
     networking.firewall.allowedTCPPorts = [
       80