Add router filter registry entry

packages/grpc-js-xds/src/http-filter/router-filter.ts

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2021 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { experimental } from '@grpc/grpc-js';
+import { Any__Output } from '../generated/google/protobuf/Any';
+import { HttpFilterConfig, registerHttpFilter } from '../http-filter';
+import Filter = experimental.Filter;
+import FilterFactory = experimental.FilterFactory;
+import BaseFilter = experimental.BaseFilter;
+
+class RouterFilter extends BaseFilter implements Filter {}
+
+class RouterFilterFactory implements FilterFactory<RouterFilter> {
+  constructor(config: HttpFilterConfig, overrideConfig?: HttpFilterConfig) {}
+
+  createFilter(callStream: experimental.CallStream): RouterFilter {
+    return new RouterFilter();
+  }
+}
+
+const ROUTER_FILTER_URL = 'type.googleapis.com/envoy.extensions.filters.http.router.v3.Router';
+
+function parseConfig(encodedConfig: Any__Output): HttpFilterConfig | null {
+  return {
+    typeUrl: ROUTER_FILTER_URL,
+    config: null
+  };
+}
+
+export function setup() {
+  registerHttpFilter(ROUTER_FILTER_URL, {
+    parseTopLevelFilterConfig: parseConfig,
+    parseOverrideFilterConfig: parseConfig,
+    httpFilterConstructor: RouterFilterFactory
+  });
+}

packages/grpc-js-xds/src/index.ts

@@ -22,6 +22,7 @@ import * as load_balancer_lrs from './load-balancer-lrs';
 import * as load_balancer_priority from './load-balancer-priority';
 import * as load_balancer_weighted_target from './load-balancer-weighted-target';
 import * as load_balancer_xds_cluster_manager from './load-balancer-xds-cluster-manager';
+import * as router_filter from './http-filter/router-filter';
 
 /**
  * Register the "xds:" name scheme with the @grpc/grpc-js library.
@@ -34,4 +35,5 @@ export function register() {
   load_balancer_priority.setup();
   load_balancer_weighted_target.setup();
   load_balancer_xds_cluster_manager.setup();
+  router_filter.setup();
 }