Allows configuration of curator instance-id via properties.

fixes gh-140

spring-cloud-zookeeper-discovery/src/main/java/org/springframework/cloud/zookeeper/discovery/ZookeeperDiscoveryProperties.java

@@ -49,6 +49,9 @@ public class ZookeeperDiscoveryProperties {
 	 */
 	private String uriSpec = DEFAULT_URI_SPEC;
 
+	/** Id used to register with zookeeper. Defaults to a random UUID. */
+	private String instanceId;
+
 	/**
 	 * Predefined host with which a service can register itself in Zookeeper. Corresponds
 	 * to the {code address} from the URI spec.
@@ -126,6 +129,14 @@ public class ZookeeperDiscoveryProperties {
 		this.uriSpec = uriSpec;
 	}
 
+	public String getInstanceId() {
+		return this.instanceId;
+	}
+
+	public void setInstanceId(String instanceId) {
+		this.instanceId = instanceId;
+	}
+
 	public void setInstanceHost(String instanceHost) {
 		this.instanceHost = instanceHost;
 		this.hostInfo.override = true;
@@ -185,6 +196,7 @@ public class ZookeeperDiscoveryProperties {
 		return "ZookeeperDiscoveryProperties{" + "enabled=" + this.enabled +
 				", root='" + this.root + '\'' +
 				", uriSpec='" + this.uriSpec + '\'' +
+				", instanceId='" + this.instanceId + '\'' +
 				", instanceHost='" + this.instanceHost + '\'' +
 				", instancePort='" + this.instancePort + '\'' +
 				", instanceSslPort='" + this.instanceSslPort + '\'' +

spring-cloud-zookeeper-discovery/src/main/java/org/springframework/cloud/zookeeper/discovery/ZookeeperServiceDiscovery.java

@@ -198,6 +198,9 @@ public class ZookeeperServiceDiscovery implements ZookeeperRegistration, Applica
 			if (this.properties.getInstanceSslPort() != null) {
 				builder.sslPort(this.properties.getInstanceSslPort());
 			}
+			if (this.properties.getInstanceId() != null) {
+				builder.id(this.properties.getInstanceId());
+			}
 			serviceInstance.set(builder.build());
 		}
 		catch (Exception e) {

spring-cloud-zookeeper-discovery/src/main/java/org/springframework/cloud/zookeeper/discovery/ZookeeperServiceInstance.java

@@ -36,6 +36,7 @@ public class ZookeeperServiceInstance implements ServiceInstance {
 	private final boolean secure;
 	private final URI uri;
 	private final Map<String, String> metadata;
+	private final org.apache.curator.x.discovery.ServiceInstance<ZookeeperInstance> serviceInstance;
 
 	/**
 	 * @param serviceId The service id to be used
@@ -43,7 +44,8 @@ public class ZookeeperServiceInstance implements ServiceInstance {
 	 */
 	public ZookeeperServiceInstance(String serviceId, org.apache.curator.x.discovery.ServiceInstance<ZookeeperInstance> serviceInstance) {
 		this.serviceId = serviceId;
-		this.host = serviceInstance.getAddress();
+		this.serviceInstance = serviceInstance;
+		this.host = this.serviceInstance.getAddress();
 		this.secure = serviceInstance.getSslPort() != null;
 		Integer port = serviceInstance.getPort();
 		if (this.secure) {
@@ -87,4 +89,8 @@ public class ZookeeperServiceInstance implements ServiceInstance {
 	public Map<String, String> getMetadata() {
 		return this.metadata;
 	}
+
+	public org.apache.curator.x.discovery.ServiceInstance<ZookeeperInstance> getServiceInstance() {
+		return this.serviceInstance;
+	}
 }

spring-cloud-zookeeper-discovery/src/test/java/org/springframework/cloud/zookeeper/discovery/ZookeeperDiscoveryPropertiesTests.java

@@ -11,13 +11,14 @@ import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
-import static org.junit.Assert.assertEquals;
+import static org.assertj.core.api.Assertions.assertThat;
 
 /**
  * @author wmz7year
  */
 @RunWith(SpringJUnit4ClassRunner.class)
 @SpringBootTest(properties = {"pring.application.name=testZookeeperDiscovery",
+		"spring.cloud.zookeeper.discovery.instance-id=zkpropstestid-123",
 		"spring.cloud.zookeeper.discovery.preferIpAddress=true",
 		"spring.cloud.zookeeper.discovery.instanceIpAddress=1.1.1.1"},
 		classes = ZookeeperDiscoveryPropertiesTests.Config.class,
@@ -29,8 +30,9 @@ public class ZookeeperDiscoveryPropertiesTests {
 
 	@Test
 	public void testPreferIpAddress() {
-		assertEquals("1.1.1.1", discoveryProperties.getInstanceHost());
-        }
+		assertThat(this.discoveryProperties.getInstanceId()).isEqualTo("zkpropstestid-123");
+		assertThat(this.discoveryProperties.getInstanceHost()).isEqualTo("1.1.1.1");
+	}
 
 	@Configuration
 	@EnableAutoConfiguration

spring-cloud-zookeeper-discovery/src/test/java/org/springframework/cloud/zookeeper/discovery/ZookeeperDiscoveryTests.java

@@ -66,6 +66,9 @@ public class ZookeeperDiscoveryTests {
 		//expect:
 		then(registeredServiceStatus(instance)).isEqualTo("UP");
 		then(instance.getMetadata().get("testMetadataKey")).isEqualTo("testMetadataValue");
+		then(instance).isInstanceOf(ZookeeperServiceInstance.class);
+		ZookeeperServiceInstance zkInstance = (ZookeeperServiceInstance) instance;
+		then(zkInstance.getServiceInstance().getId()).isEqualTo("ribbon-instance-id-123");
 	}
 
 	@Test public void should_present_application_name_as_id_of_the_service_instance() {

spring-cloud-zookeeper-discovery/src/test/resources/application-ribbon.yml

@@ -7,6 +7,7 @@ spring:
         metadata:
           testMetadataKey: testMetadataValue
         uriSpec: "{scheme}://{address}:{port}/contextPath"
+        instance-id: ribbon-instance-id-123
 management:
   security:
     enabled: false