Adds metadata field on Route and RouteDefinition

Fixes gh-1021

docs/src/main/asciidoc/spring-cloud-gateway.adoc

@@ -1476,6 +1476,34 @@ spring:
 
 For some usages of the gateway, properties will be adequate, but some production use cases will benefit from loading configuration from an external source, such as a database. Future milestone versions will have `RouteDefinitionLocator` implementations based off of Spring Data Repositories such as: Redis, MongoDB and Cassandra.
 
+== Route metadata configuration
+Additional parameters can be configured for each route using metadata:
+
+.application.yml
+[source,yaml]
+----
+spring:
+  cloud:
+    gateway:
+      routes:
+      - id: route_with_metadata
+        uri: https://example.org
+        metadata:
+          optionName: "OptionValue"
+          compositeObject:
+            name: "value"
+          iAmNumber: 1
+----
+
+All metadata properties could be acquired from exchange:
+```
+Route route = exchange.getAttribute(GATEWAY_ROUTE_ATTR);
+// get all metadata properties
+route.getMetadata();
+// get a single metadata property
+route.getMetadata(someKey);
+```
+
 === Fluent Java Routes API
 To allow for simple configuration in Java, there is a fluent API defined in the `RouteLocatorBuilder` bean.
 
@@ -1495,6 +1523,7 @@ public RouteLocator customRouteLocator(RouteLocatorBuilder builder, ThrottleGate
                 .filters(f ->
                         f.addResponseHeader("X-AnotherHeader", "baz"))
                 .uri("http://httpbin.org:80")
+                .metadata("key", "value")
             )
             .route(r -> r.order(-1)
                 .host("**.throttle.org").and().path("/get")
@@ -1503,6 +1532,7 @@ public RouteLocator customRouteLocator(RouteLocatorBuilder builder, ThrottleGate
                         10,
                         TimeUnit.SECONDS)))
                 .uri("http://httpbin.org:80")
+                .metadata("key", "value")
             )
             .build();
 }

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/actuate/GatewayControllerEndpoint.java

@@ -32,6 +32,7 @@ import org.springframework.cloud.gateway.route.Route;
 import org.springframework.cloud.gateway.route.RouteDefinitionWriter;
 import org.springframework.cloud.gateway.route.RouteLocator;
 import org.springframework.http.ResponseEntity;
+import org.springframework.util.CollectionUtils;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 
@@ -59,6 +60,9 @@ public class GatewayControllerEndpoint extends AbstractGatewayControllerEndpoint
 		r.put("uri", route.getUri().toString());
 		r.put("order", route.getOrder());
 		r.put("predicate", route.getPredicate().toString());
+		if (!CollectionUtils.isEmpty(route.getMetadata())) {
+			r.put("metadata", route.getMetadata());
+		}
 
 		ArrayList<String> filters = new ArrayList<>();
 

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/actuate/GatewayLegacyControllerEndpoint.java

@@ -33,6 +33,7 @@ import org.springframework.cloud.gateway.route.RouteDefinitionLocator;
 import org.springframework.cloud.gateway.route.RouteDefinitionWriter;
 import org.springframework.cloud.gateway.route.RouteLocator;
 import org.springframework.http.ResponseEntity;
+import org.springframework.util.CollectionUtils;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 
@@ -81,6 +82,10 @@ public class GatewayLegacyControllerEndpoint extends AbstractGatewayControllerEn
 						obj.put("filters", filters);
 					}
 
+					if (!CollectionUtils.isEmpty(route.getMetadata())) {
+						obj.put("metadata", route.getMetadata());
+					}
+
 					if (!obj.isEmpty()) {
 						r.put("route_object", obj);
 					}

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/route/Route.java

@@ -21,7 +21,9 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Objects;
 import java.util.function.Predicate;
 
@@ -50,14 +52,24 @@ public class Route implements Ordered {
 
 	private final List<GatewayFilter> gatewayFilters;
 
+	private final Map<String, Object> metadata;
+
+	@Deprecated
 	private Route(String id, URI uri, int order,
 			AsyncPredicate<ServerWebExchange> predicate,
 			List<GatewayFilter> gatewayFilters) {
+		this(id, uri, order, predicate, gatewayFilters, new HashMap<>());
+	}
+
+	private Route(String id, URI uri, int order,
+			AsyncPredicate<ServerWebExchange> predicate,
+			List<GatewayFilter> gatewayFilters, Map<String, Object> metadata) {
 		this.id = id;
 		this.uri = uri;
 		this.order = order;
 		this.predicate = predicate;
 		this.gatewayFilters = gatewayFilters;
+		this.metadata = metadata;
 	}
 
 	public static Builder builder() {
@@ -65,8 +77,12 @@ public class Route implements Ordered {
 	}
 
 	public static Builder builder(RouteDefinition routeDefinition) {
-		return new Builder().id(routeDefinition.getId()).uri(routeDefinition.getUri())
-				.order(routeDefinition.getOrder());
+		// @formatter:off
+		return new Builder().id(routeDefinition.getId())
+				.uri(routeDefinition.getUri())
+				.order(routeDefinition.getOrder())
+				.metadata(routeDefinition.getMetadata());
+		// @formatter:on
 	}
 
 	public static AsyncBuilder async() {
@@ -74,8 +90,12 @@ public class Route implements Ordered {
 	}
 
 	public static AsyncBuilder async(RouteDefinition routeDefinition) {
+		// @formatter:off
 		return new AsyncBuilder().id(routeDefinition.getId())
-				.uri(routeDefinition.getUri()).order(routeDefinition.getOrder());
+				.uri(routeDefinition.getUri())
+				.order(routeDefinition.getOrder())
+				.metadata(routeDefinition.getMetadata());
+		// @formatter:on
 	}
 
 	public String getId() {
@@ -98,6 +118,10 @@ public class Route implements Ordered {
 		return Collections.unmodifiableList(this.gatewayFilters);
 	}
 
+	public Map<String, Object> getMetadata() {
+		return Collections.unmodifiableMap(metadata);
+	}
+
 	@Override
 	public boolean equals(Object o) {
 		if (this == o) {
@@ -107,15 +131,17 @@ public class Route implements Ordered {
 			return false;
 		}
 		Route route = (Route) o;
-		return Objects.equals(id, route.id) && Objects.equals(uri, route.uri)
-				&& Objects.equals(order, route.order)
-				&& Objects.equals(predicate, route.predicate)
-				&& Objects.equals(gatewayFilters, route.gatewayFilters);
+		return this.order == route.order && Objects.equals(this.id, route.id)
+				&& Objects.equals(this.uri, route.uri)
+				&& Objects.equals(this.predicate, route.predicate)
+				&& Objects.equals(this.gatewayFilters, route.gatewayFilters)
+				&& Objects.equals(this.metadata, route.metadata);
 	}
 
 	@Override
 	public int hashCode() {
-		return Objects.hash(id, uri, predicate, gatewayFilters);
+		return Objects.hash(this.id, this.uri, this.order, this.predicate,
+				this.gatewayFilters, this.metadata);
 	}
 
 	@Override
@@ -126,6 +152,7 @@ public class Route implements Ordered {
 		sb.append(", order=").append(order);
 		sb.append(", predicate=").append(predicate);
 		sb.append(", gatewayFilters=").append(gatewayFilters);
+		sb.append(", metadata=").append(metadata);
 		sb.append('}');
 		return sb.toString();
 	}
@@ -140,6 +167,8 @@ public class Route implements Ordered {
 
 		protected List<GatewayFilter> gatewayFilters = new ArrayList<>();
 
+		protected Map<String, Object> metadata = new HashMap<>();
+
 		protected AbstractBuilder() {
 		}
 
@@ -177,6 +206,21 @@ public class Route implements Ordered {
 			return getThis();
 		}
 
+		public B replaceMetadata(Map<String, Object> metadata) {
+			this.metadata = metadata;
+			return getThis();
+		}
+
+		public B metadata(Map<String, Object> metadata) {
+			this.metadata.putAll(metadata);
+			return getThis();
+		}
+
+		public B metadata(String key, Object value) {
+			this.metadata.put(key, value);
+			return getThis();
+		}
+
 		public abstract AsyncPredicate<ServerWebExchange> getPredicate();
 
 		public B replaceFilters(List<GatewayFilter> gatewayFilters) {
@@ -205,7 +249,7 @@ public class Route implements Ordered {
 			Assert.notNull(predicate, "predicate can not be null");
 
 			return new Route(this.id, this.uri, this.order, predicate,
-					this.gatewayFilters);
+					this.gatewayFilters, this.metadata);
 		}
 
 	}

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/route/RouteDefinition.java

@@ -18,7 +18,9 @@ package org.springframework.cloud.gateway.route;
 
 import java.net.URI;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Objects;
 import java.util.UUID;
 
@@ -52,6 +54,8 @@ public class RouteDefinition {
 	@NotNull
 	private URI uri;
 
+	private Map<String, Object> metadata = new HashMap<>();
+
 	private int order = 0;
 
 	public RouteDefinition() {
@@ -115,6 +119,14 @@ public class RouteDefinition {
 		this.order = order;
 	}
 
+	public Map<String, Object> getMetadata() {
+		return metadata;
+	}
+
+	public void setMetadata(Map<String, Object> metadata) {
+		this.metadata = metadata;
+	}
+
 	@Override
 	public boolean equals(Object o) {
 		if (this == o) {
@@ -123,22 +135,25 @@ public class RouteDefinition {
 		if (o == null || getClass() != o.getClass()) {
 			return false;
 		}
-		RouteDefinition routeDefinition = (RouteDefinition) o;
-		return Objects.equals(id, routeDefinition.id)
-				&& Objects.equals(predicates, routeDefinition.predicates)
-				&& Objects.equals(order, routeDefinition.order)
-				&& Objects.equals(uri, routeDefinition.uri);
+		RouteDefinition that = (RouteDefinition) o;
+		return this.order == that.order && Objects.equals(this.id, that.id)
+				&& Objects.equals(this.predicates, that.predicates)
+				&& Objects.equals(this.filters, that.filters)
+				&& Objects.equals(this.uri, that.uri)
+				&& Objects.equals(this.metadata, that.metadata);
 	}
 
 	@Override
 	public int hashCode() {
-		return Objects.hash(id, predicates, uri);
+		return Objects.hash(this.id, this.predicates, this.filters, this.uri,
+				this.metadata, this.order);
 	}
 
 	@Override
 	public String toString() {
 		return "RouteDefinition{" + "id='" + id + '\'' + ", predicates=" + predicates
-				+ ", filters=" + filters + ", uri=" + uri + ", order=" + order + '}';
+				+ ", filters=" + filters + ", uri=" + uri + ", order=" + order
+				+ ", metadata=" + metadata + '}';
 	}
 
 }

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/actuate/GatewayControllerEndpointTests.java

@@ -19,6 +19,7 @@ package org.springframework.cloud.gateway.actuate;
 import java.util.List;
 import java.util.Map;
 
+import org.assertj.core.util.Maps;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
@@ -80,6 +81,18 @@ public class GatewayControllerEndpointTests {
 				});
 	}
 
+	@Test
+	public void testRouteReturnsMetadata() {
+		testClient.get()
+				.uri("http://localhost:" + port
+						+ "/actuator/gateway/routes/route_with_metadata")
+				.exchange().expectStatus().isOk().expectBody().jsonPath("$.metadata")
+				.value(map -> assertThat((Map<String, Object>) map).hasSize(3)
+						.containsEntry("optionName", "OptionValue")
+						.containsEntry("iAmNumber", 1).containsEntry("compositeObject",
+								Maps.newHashMap("name", "value")));
+	}
+
 	@SpringBootConfiguration
 	@EnableAutoConfiguration
 	@Import(PermitAllSecurityConfiguration.class)

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/route/RouteDefinitionTest.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2013-2019 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
+ *
+ *      https://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.gateway.route;
+
+import java.util.Map;
+
+import org.assertj.core.util.Maps;
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Stefan Stus
+ */
+public class RouteDefinitionTest {
+
+	@Test
+	public void addRouteDefinitionKeepsExistingMetadata() {
+		Map<String, Object> originalMetadata = Maps.newHashMap("key", "value");
+		Map<String, Object> newMetadata = Maps.newHashMap("key2", "value2");
+
+		RouteDefinition routeDefinition = new RouteDefinition();
+		routeDefinition.setMetadata(originalMetadata);
+		routeDefinition.getMetadata().putAll(newMetadata);
+
+		assertThat(routeDefinition.getMetadata()).hasSize(2)
+				.containsAllEntriesOf(originalMetadata).containsAllEntriesOf(newMetadata);
+	}
+
+	@Test
+	public void setRouteDefinitionReplacesExistingMetadata() {
+		Map<String, Object> originalMetadata = Maps.newHashMap("key", "value");
+		Map<String, Object> newMetadata = Maps.newHashMap("key2", "value2");
+
+		RouteDefinition routeDefinition = new RouteDefinition();
+		routeDefinition.setMetadata(originalMetadata);
+		routeDefinition.setMetadata(newMetadata);
+
+		assertThat(routeDefinition.getMetadata()).isEqualTo(newMetadata);
+	}
+
+	@Test
+	public void addSingleMetadataEntryKeepsOriginalMetadata() {
+		Map<String, Object> originalMetadata = Maps.newHashMap("key", "value");
+
+		RouteDefinition routeDefinition = new RouteDefinition();
+		routeDefinition.setMetadata(originalMetadata);
+		routeDefinition.getMetadata().put("key2", "value2");
+
+		assertThat(routeDefinition.getMetadata()).hasSize(2)
+				.containsAllEntriesOf(originalMetadata).containsEntry("key2", "value2");
+	}
+
+}

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/route/RouteTests.java

@@ -16,6 +16,10 @@
 
 package org.springframework.cloud.gateway.route;
 
+import java.net.URI;
+import java.util.HashMap;
+
+import org.assertj.core.util.Maps;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
@@ -57,4 +61,37 @@ public class RouteTests {
 		Route.async().id("1").predicate(exchange -> true).uri("/pathonly");
 	}
 
+	@Test
+	public void defaultMetadataToEmpty() {
+		Route route = Route.async().id("1").predicate(exchange -> true)
+				.uri("http://acme.com:8080").build();
+
+		assertThat(route.getMetadata()).isEmpty();
+	}
+
+	@Test
+	public void isAbleToAddMetadata() {
+		Route route = Route.async().id("1").predicate(exchange -> true)
+				.uri("http://acme.com:8080").metadata(Maps.newHashMap("key", "value"))
+				.metadata("key2", "value2").build();
+
+		assertThat(route.getMetadata()).hasSize(2).containsEntry("key", "value")
+				.containsEntry("key2", "value2");
+	}
+
+	@Test
+	public void metadataIsAddedFromDefinition() {
+		RouteDefinition definition = new RouteDefinition();
+		definition.setId("1");
+		definition.setUri(URI.create("http://acme.com:8080"));
+		HashMap<String, Object> metadata = new HashMap<>();
+		metadata.put("key", "value");
+		metadata.put("key2", "value2");
+		definition.setMetadata(metadata);
+		Route route = Route.async(definition).predicate(exchange -> true).build();
+
+		assertThat(route.getMetadata()).hasSize(2).containsEntry("key", "value")
+				.containsEntry("key2", "value2");
+	}
+
 }

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/route/builder/RouteBuilderTests.java

@@ -17,9 +17,12 @@
 package org.springframework.cloud.gateway.route.builder;
 
 import java.net.URI;
+import java.util.Map;
 
+import org.assertj.core.util.Maps;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+
 import reactor.test.StepVerifier;
 
 import org.springframework.beans.factory.annotation.Autowired;
@@ -63,6 +66,31 @@ public class RouteBuilderTests {
 				.expectComplete().verify();
 	}
 
+	@Test
+	public void testRouteOptionsPropagatedToRoute() {
+		Map<String, Object> routeMetadata = Maps.newHashMap("key", "value");
+		RouteLocator routeLocator = this.routeLocatorBuilder.routes()
+				.route("test1", r -> r.host("*.somehost.org").and().path("/somepath")
+						.filters(f -> f.addRequestHeader("header1", "header-value-1"))
+						.uri("http://someuri").metadata("key", "value"))
+				.route("test2", r -> r.host("*.somehost2.org")
+						.filters(f -> f.addResponseHeader("header-response-1",
+								"header-response-1"))
+						.uri("https://httpbin.org:9090"))
+				.build();
+
+		StepVerifier.create(routeLocator.getRoutes())
+				.expectNextMatches(
+						r -> r.getId().equals("test1") && r.getFilters().size() == 1
+								&& r.getUri().equals(URI.create("http://someuri:80"))
+								&& r.getMetadata().equals(routeMetadata))
+				.expectNextMatches(r -> r.getId().equals("test2")
+						&& r.getFilters().size() == 1
+						&& r.getUri().equals(URI.create("https://httpbin.org:9090"))
+						&& r.getMetadata().isEmpty())
+				.expectComplete().verify();
+	}
+
 	@EnableAutoConfiguration
 	@Configuration
 	public static class SpringConfig {

spring-cloud-gateway-core/src/test/resources/application.yml

@@ -387,6 +387,19 @@ spring:
         - name: Path
           args:
             pattern: /**
+      # =====================================
+      - id: route_with_metadata
+        uri: ${test.uri}
+        order: 10000
+        predicates:
+          - name: Path
+            args:
+              pattern: /route_with_metadata
+        metadata:
+          optionName: "OptionValue"
+          compositeObject:
+              name: "value"
+          iAmNumber: 1
 
 hystrix.command.successcmd.execution.isolation.thread.timeoutInMilliseconds: 5000