Dynamic filtering on Zuul SimpleRouteLocator.getRoutes()

* Introduce getRoutesMap() so subclasses can have read/write access to configured/discovered routes.

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/SimpleRouteLocator.java

@@ -23,7 +23,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.concurrent.atomic.AtomicReference;
-
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.springframework.cloud.netflix.zuul.filters.ZuulProperties.ZuulRoute;
@@ -65,12 +64,9 @@ public class SimpleRouteLocator implements RouteLocator, Ordered {
 
 	@Override
 	public List<Route> getRoutes() {
-		if (this.routes.get() == null) {
-			this.routes.set(locateRoutes());
-		}
 		List<Route> values = new ArrayList<>();
-		for (String url : this.routes.get().keySet()) {
-			ZuulRoute route = this.routes.get().get(url);
+		for (Entry<String, ZuulRoute> entry : getRoutesMap().entrySet()) {
+			ZuulRoute route = entry.getValue();
 			String path = route.getPath();
 			values.add(getRoute(route, path));
 		}
@@ -89,14 +85,20 @@ public class SimpleRouteLocator implements RouteLocator, Ordered {
 
 	}
 
+	protected Map<String, ZuulRoute> getRoutesMap() {
+		if (this.routes.get() == null) {
+			this.routes.set(locateRoutes());
+		}
+		return this.routes.get();
+	}
+
 	protected Route getSimpleMatchingRoute(final String path) {
 		if (log.isDebugEnabled()) {
 			log.debug("Finding route for path: " + path);
 		}
 
-		if (this.routes.get() == null) {
-			this.routes.set(locateRoutes());
-		}
+		// This is called for the initialization done in getRoutesMap()
+		getRoutesMap();
 
 		if (log.isDebugEnabled()) {
 			log.debug("servletPath=" + this.dispatcherServletPath);
@@ -116,7 +118,7 @@ public class SimpleRouteLocator implements RouteLocator, Ordered {
 
 	protected ZuulRoute getZuulRoute(String adjustedPath) {
 		if (!matchesIgnoredPatterns(adjustedPath)) {
-			for (Entry<String, ZuulRoute> entry : this.routes.get().entrySet()) {
+			for (Entry<String, ZuulRoute> entry : getRoutesMap().entrySet()) {
 				String pattern = entry.getKey();
 				log.debug("Matching pattern:" + pattern);
 				if (this.pathMatcher.match(pattern, adjustedPath)) {

spring-cloud-netflix-core/src/test/java/org/springframework/cloud/netflix/zuul/filters/SimpleRouteLocatorTests.java

@@ -0,0 +1,112 @@
+/*
+ * Copyright 2013-2014 the original author or 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.
+ */
+
+package org.springframework.cloud.netflix.zuul.filters;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import static org.hamcrest.CoreMatchers.hasItem;
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.CoreMatchers.nullValue;
+import static org.hamcrest.collection.IsCollectionWithSize.hasSize;
+import static org.junit.Assert.assertThat;
+import org.junit.Test;
+import org.springframework.cloud.netflix.zuul.filters.ZuulProperties.ZuulRoute;
+
+/**
+ * @author Tom Cawley
+ */
+public class SimpleRouteLocatorTests {
+	private ZuulProperties zuul = new ZuulProperties();
+
+	public SimpleRouteLocatorTests() {
+	}
+
+	@Test
+	public void test_getRoutesDefaultRouteAcceptor() {
+		RouteLocator locator = new SimpleRouteLocator("/", this.zuul);
+		this.zuul.getRoutes().clear();
+		this.zuul.getRoutes().put("foo", new ZuulRoute("/foo/**", "foo"));
+
+		assertThat(locator.getRoutes(), hasItem(createRoute("foo", "/**", "/foo")));
+	}
+
+	@Test
+	public void test_getRoutesFilterRouteAcceptor() {
+		RouteLocator locator = new FilteringRouteLocator("/", this.zuul);
+		this.zuul.getRoutes().clear();
+		this.zuul.getRoutes().put("foo", new ZuulRoute("/foo/**", "foo"));
+		this.zuul.getRoutes().put("bar", new ZuulRoute("/bar/**", "bar"));
+
+		final List<Route> routes = locator.getRoutes();
+		assertThat(routes, hasItem(createRoute("bar", "/**", "/bar")));
+		assertThat(routes, hasSize(1));
+	}
+
+	@Test
+	public void test_getMatchingRouteFilterRouteAcceptor() {
+		RouteLocator locator = new FilteringRouteLocator("/", this.zuul);
+		this.zuul.getRoutes().clear();
+		this.zuul.getRoutes().put("foo", new ZuulRoute("/foo/**", "foo"));
+		this.zuul.getRoutes().put("bar", new ZuulRoute("/bar/**", "bar"));
+
+		assertThat(locator.getMatchingRoute("/foo/1"), nullValue());
+		assertThat(locator.getMatchingRoute("/bar/1"), is(createRoute("bar", "/1", "/bar")));
+	}
+
+	private Route createRoute(String id, String path, String prefix) {
+		return new Route(id, path, id, prefix, false, null);
+	}
+
+	private static class FilteringRouteLocator extends SimpleRouteLocator {
+		public FilteringRouteLocator(String servletPath, ZuulProperties properties) {
+			super(servletPath, properties);
+		}
+
+		@Override
+		public List<Route> getRoutes() {
+			List<Route> values = new ArrayList<>();
+
+			for (Entry<String, ZuulRoute> entry : getRoutesMap().entrySet()) {
+				ZuulRoute route = entry.getValue();
+				if (acceptRoute(route)) {
+					String path = route.getPath();
+					values.add(getRoute(route, path));
+				}
+			}
+			return values;
+		}
+
+		private boolean acceptRoute(ZuulRoute route) {
+			return route != null && !(route.getId().equals("foo"));
+		}
+
+		protected Route getRoute(ZuulRoute route, String path) {
+			if (acceptRoute(route)) {
+				return super.getRoute(route, path);
+			}
+			return null;
+		}
+
+		// For testing, expose as public so we can call getRoutesMap() directly.
+		@Override
+		public Map<String, ZuulRoute> getRoutesMap() {
+			return super.getRoutesMap();
+		}
+	}
+}