Move generic config server discovery to spring-cloud-config

Fixes gh-302 (spring-cloud-consul and -zookeeper my still need
to add some bootstrap config to ensure that the DiscoveryClient
is available in bootstrap context).

spring-cloud-config-client/src/main/java/org/springframework/cloud/config/client/DiscoveryClientConfigServiceBootstrapConfiguration.java

@@ -0,0 +1,86 @@
+/*
+ * 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.config.client;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.cloud.client.ServiceInstance;
+import org.springframework.cloud.client.discovery.DiscoveryClient;
+import org.springframework.cloud.util.UtilAutoConfiguration;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+import org.springframework.context.event.ContextRefreshedEvent;
+import org.springframework.context.event.EventListener;
+
+/**
+ * Bootstrap configuration for a config client that wants to lookup the config server via
+ * discovery.
+ *
+ * @author Dave Syer
+ */
+@ConditionalOnProperty(value = "spring.cloud.config.discovery.enabled", matchIfMissing = false)
+@Configuration
+@Import({ UtilAutoConfiguration.class })
+public class DiscoveryClientConfigServiceBootstrapConfiguration {
+
+	private static Log logger = LogFactory.getLog(DiscoveryClientConfigServiceBootstrapConfiguration.class);
+
+	@Autowired
+	private ConfigClientProperties config;
+
+	@Autowired
+	private DiscoveryClient client;
+
+	@EventListener(ContextRefreshedEvent.class)
+	public void onApplicationEvent(ContextRefreshedEvent event) {
+		refresh();
+	}
+
+	private void refresh() {
+		try {
+			logger.debug("Locating configserver via discovery");
+			ServiceInstance server = this.client
+					.getInstances(this.config.getDiscovery().getServiceId()).get(0);
+			String url = getHomePage(server);
+			if (server.getMetadata().containsKey("password")) {
+				String user = server.getMetadata().get("user");
+				user = user == null ? "user" : user;
+				this.config.setUsername(user);
+				String password = server.getMetadata().get("password");
+				this.config.setPassword(password);
+			}
+			if (server.getMetadata().containsKey("configPath")) {
+				String path = server.getMetadata().get("configPath");
+				if (url.endsWith("/") && path.startsWith("/")) {
+					url = url.substring(0, url.length() - 1);
+				}
+				url = url + path;
+			}
+			this.config.setUri(url);
+		}
+		catch (Exception ex) {
+			logger.warn("Could not locate configserver via discovery", ex);
+		}
+	}
+
+	private String getHomePage(ServiceInstance server) {
+		return server.getUri().toString() + "/";
+	}
+
+}

spring-cloud-config-client/src/main/resources/META-INF/spring.factories

@@ -4,4 +4,5 @@ org.springframework.cloud.config.client.ConfigClientAutoConfiguration
 
 # Bootstrap components
 org.springframework.cloud.bootstrap.BootstrapConfiguration=\
-org.springframework.cloud.config.client.ConfigServiceBootstrapConfiguration
+org.springframework.cloud.config.client.ConfigServiceBootstrapConfiguration,\
+org.springframework.cloud.config.client.DiscoveryClientConfigServiceBootstrapConfiguration