Gh 304 add discovery clients order support (#446)

NOTE: This can only be merged after https://github.com/spring-cloud/spring-cloud-commons/pull/412 is has been merged.

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

@@ -59,7 +59,7 @@ public class ConsulDiscoveryClient implements DiscoveryClient {
 
 	@Deprecated
 	public ConsulDiscoveryClient(ConsulClient client, ConsulDiscoveryProperties properties,
-				LocalResolver localResolver) {
+	                             LocalResolver localResolver) {
 		this(client, properties);
 	}
 
@@ -74,7 +74,7 @@ public class ConsulDiscoveryClient implements DiscoveryClient {
 	}
 
 	public List<ServiceInstance> getInstances(final String serviceId,
-			final QueryParams queryParams) {
+	                                          final QueryParams queryParams) {
 		List<ServiceInstance> instances = new ArrayList<>();
 
 		addInstancesToList(instances, serviceId, queryParams);
@@ -83,7 +83,7 @@ public class ConsulDiscoveryClient implements DiscoveryClient {
 	}
 
 	private void addInstancesToList(List<ServiceInstance> instances, String serviceId,
-			QueryParams queryParams) {
+	                                QueryParams queryParams) {
 
 		String aclToken = properties.getAclToken();
 		Response<List<HealthService>> services;
@@ -99,11 +99,11 @@ public class ConsulDiscoveryClient implements DiscoveryClient {
 		}
 		for (HealthService service : services.getValue()) {
 			String host = findHost(service);
-			
-			Map<String,String> metadata = getMetadata(service);
+
+			Map<String, String> metadata = getMetadata(service);
 			boolean secure = false;
-			if(metadata.containsKey("secure")) {
-			    secure = Boolean.parseBoolean(metadata.get("secure"));
+			if (metadata.containsKey("secure")) {
+				secure = Boolean.parseBoolean(metadata.get("secure"));
 			}
 			instances.add(new DefaultServiceInstance(serviceId, host, service
 					.getService().getPort(), secure, metadata));
@@ -133,4 +133,9 @@ public class ConsulDiscoveryClient implements DiscoveryClient {
 					.keySet());
 		}
 	}
+
+	@Override
+	public int getOrder() {
+		return this.properties.getOrder();
+	}
 }

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

@@ -35,6 +35,7 @@ import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler;
 
 /**
  * @author Spencer Gibb
+ * @author Olga Maciaszek-Sharma
  */
 @Configuration
 @ConditionalOnConsulEnabled

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

@@ -164,6 +164,11 @@ public class ConsulDiscoveryProperties {
 	 */
 	private Boolean healthCheckTlsSkipVerify;
 
+	/**
+	 * Order of the discovery client used by `CompositeDiscoveryClient` for sorting available clients.
+	 */
+	private int order = 0;
+
 	@SuppressWarnings("unused")
 	private ConsulDiscoveryProperties() {}
 
@@ -464,6 +469,14 @@ public class ConsulDiscoveryProperties {
 		this.healthCheckTlsSkipVerify = healthCheckTlsSkipVerify;
 	}
 
+	public int getOrder() {
+		return order;
+	}
+
+	public void setOrder(int order) {
+		this.order = order;
+	}
+
 	@Override
 	public String toString() {
 		return "ConsulDiscoveryProperties{" +
@@ -502,6 +515,7 @@ public class ConsulDiscoveryProperties {
 				", registerHealthCheck=" + registerHealthCheck +
 				", failFast=" + failFast +
 				", healthCheckTlsSkipVerify=" + healthCheckTlsSkipVerify +
+				", order=" + order +
 				'}';
 	}