Filter services by tag.

fixes gh-18

spring-cloud-consul-discovery/src/main/java/org/springframework/cloud/consul/discovery/ConsulDiscoveryProperties.java

@@ -18,7 +18,9 @@ package org.springframework.cloud.consul.discovery;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 import lombok.AccessLevel;
 import lombok.Data;
@@ -101,6 +103,12 @@ public class ConsulDiscoveryProperties {
 	/** Suffix to use when registering management service */
 	private String managementSuffix = MANAGEMENT;
 
+	/**
+	 * Map of serviceId's -> tag to query for in server list.
+	 * This allows filtering services by a single tag.
+	 */
+	private Map<String, String> serverListQueryTags = new HashMap<>();
+
 	private ConsulDiscoveryProperties() {}
 
 	public ConsulDiscoveryProperties(InetUtils inetUtils) {

spring-cloud-consul-discovery/src/main/java/org/springframework/cloud/consul/discovery/ConsulRibbonClientConfiguration.java

@@ -66,8 +66,8 @@ public class ConsulRibbonClientConfiguration {
 
 	@Bean
 	@ConditionalOnMissingBean
-	public ServerList<?> ribbonServerList(IClientConfig config) {
-		ConsulServerList serverList = new ConsulServerList(client);
+	public ServerList<?> ribbonServerList(IClientConfig config, ConsulDiscoveryProperties properties) {
+		ConsulServerList serverList = new ConsulServerList(client, properties);
 		serverList.initWithNiwsConfig(config);
 		return serverList;
 	}

spring-cloud-consul-discovery/src/main/java/org/springframework/cloud/consul/discovery/ConsulServerList.java

@@ -33,11 +33,13 @@ import com.netflix.loadbalancer.AbstractServerList;
 public class ConsulServerList extends AbstractServerList<ConsulServer> {
 
 	private final ConsulClient client;
+	private final ConsulDiscoveryProperties properties;
 
 	private String serviceId;
 
-	public ConsulServerList(ConsulClient client) {
+	public ConsulServerList(ConsulClient client, ConsulDiscoveryProperties properties) {
 		this.client = client;
+		this.properties = properties;
 	}
 
 	@Override
@@ -59,8 +61,9 @@ public class ConsulServerList extends AbstractServerList<ConsulServer> {
 		if (client == null) {
 			return Collections.emptyList();
 		}
+		String tag = this.properties.getServerListQueryTags().get(this.serviceId); // null is ok
 		Response<List<CatalogService>> response = client.getCatalogService(
-				this.serviceId, QueryParams.DEFAULT);
+				this.serviceId, tag, QueryParams.DEFAULT);
 		if (response.getValue() == null || response.getValue().isEmpty()) {
 			return Collections.emptyList();
 		}

spring-cloud-consul-discovery/src/test/java/org/springframework/cloud/consul/discovery/ConsulServerListTests.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright 2013-2016 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.consul.discovery;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+
+import com.ecwid.consul.v1.ConsulClient;
+import com.ecwid.consul.v1.agent.model.NewService;
+import com.netflix.client.config.DefaultClientConfigImpl;
+
+import org.junit.Test;
+import org.springframework.cloud.util.InetUtils;
+import org.springframework.cloud.util.InetUtilsProperties;
+
+import static org.junit.Assert.*;
+import static org.hamcrest.Matchers.*;
+
+/**
+ * @author Spencer Gibb
+ */
+public class ConsulServerListTests {
+
+	@Test
+	public void tagsWork() {
+		String name = "consulServerListTestsService";
+		ConsulClient consul = new ConsulClient();
+		NewService nonTagged = new NewService();
+		nonTagged.setAddress("localhost");
+		nonTagged.setId(name+"NonTagged");
+		nonTagged.setName(name);
+		nonTagged.setPort(8080);
+
+		NewService tagged = new NewService();
+		tagged.setAddress("localhost");
+		tagged.setId(name+"Tagged");
+		tagged.setName(name);
+		tagged.setPort(9080);
+		String tag = "mytag";
+		tagged.setTags(Arrays.asList(tag));
+
+		try {
+			consul.agentServiceRegister(nonTagged);
+			consul.agentServiceRegister(tagged);
+
+			InetUtils inetUtils = new InetUtils(new InetUtilsProperties());
+			DefaultClientConfigImpl config = new DefaultClientConfigImpl();
+			config.setClientName(tagged.getName());
+
+			ConsulServerList serverList = new ConsulServerList(consul, new ConsulDiscoveryProperties(inetUtils));
+			serverList.initWithNiwsConfig(config);
+
+			List<ConsulServer> servers = serverList.getInitialListOfServers();
+			assertThat("servers was wrong size", servers, hasSize(2));
+
+			serverList = new ConsulServerList(consul, getProperties(name, tag, inetUtils));
+			serverList.initWithNiwsConfig(config);
+
+			servers = serverList.getInitialListOfServers();
+			assertThat("servers was wrong size", servers, hasSize(1));
+			ConsulServer server = servers.get(0);
+			assertThat("server was wrong", server.getPort(), is(9080));
+		} finally {
+			consul.agentServiceDeregister(nonTagged.getId());
+			consul.agentServiceDeregister(tagged.getId());
+		}
+	}
+
+	private ConsulDiscoveryProperties getProperties(String name, String tag, InetUtils inetUtils) {
+		ConsulDiscoveryProperties properties = new ConsulDiscoveryProperties(inetUtils);
+		HashMap<String, String> map = new HashMap<>();
+		map.put(name, tag);
+		properties.setServerListQueryTags(map);
+		return properties;
+	}
+}