Updated service-discovery api on Microservices part

Author: artem-v

services/src/main/java/io/scalecube/services/Microservices.java

@@ -302,16 +302,12 @@ public ServiceDiscoveryContext discovery(String id) {
   }
 
   /**
-   * Returns composite service discovery context.
+   * Function to subscribe and listen on {@code ServiceDiscoveryEvent} events.
    *
-   * @return composite service discovery context
+   * @return stream of {@code ServiceDiscoveryEvent} events
    */
-  public ServiceDiscoveryContext discovery() {
-    return ServiceDiscoveryContext.builder()
-        .id("composite-discovery")
-        .address(Address.NULL_ADDRESS)
-        .discovery(compositeDiscovery)
-        .build();
+  public Flux<ServiceDiscoveryEvent> listenDiscovery() {
+    return compositeDiscovery.listen();
   }
 
   /**

services/src/test/java/io/scalecube/services/ServiceRegistryTest.java

@@ -50,7 +50,7 @@ public void test_added_removed_registration_events(MetadataCodec metadataCodec)
             .transport(RSocketServiceTransport::new)
             .startAwait();
 
-    seed.discovery().listen().subscribe(events);
+    seed.listenDiscovery().subscribe(events);
 
     Address seedAddress = seed.discovery("seed").address();
 
@@ -96,7 +96,7 @@ public void test_listen_to_discovery_events(MetadataCodec metadataCodec) {
             .startAwait();
     cluster.add(seed);
 
-    seed.discovery().listen().subscribe(processor);
+    seed.listenDiscovery().subscribe(processor);
 
     Address seedAddress = seed.discovery("seed").address();
 
@@ -161,7 +161,7 @@ public void test_delayed_listen_to_discovery_events(MetadataCodec metadataCodec)
             .startAwait();
     cluster.add(seed);
 
-    seed.discovery().listen().subscribe(processor);
+    seed.listenDiscovery().subscribe(processor);
 
     Address seedAddress = seed.discovery("seed").address();
 

services/src/test/java/io/scalecube/services/sut/AnnotationServiceImpl.java

@@ -13,7 +13,7 @@ public class AnnotationServiceImpl implements AnnotationService {
   @AfterConstruct
   void init(Microservices microservices) {
     this.serviceDiscoveryEvents = ReplayProcessor.create();
-    microservices.discovery().listen().subscribe(serviceDiscoveryEvents);
+    microservices.listenDiscovery().subscribe(serviceDiscoveryEvents);
   }
 
   @Override

services/src/test/java/io/scalecube/services/transport/rsocket/RSocketServiceTransportTest.java

@@ -82,8 +82,7 @@ public void test_remote_node_died_mono_never() throws Exception {
     sub1.set(serviceCall.requestOne(JUST_NEVER).doOnError(exceptionHolder::set).subscribe());
 
     gateway
-        .discovery()
-        .listen()
+        .listenDiscovery()
         .filter(ServiceDiscoveryEvent::isEndpointRemoved)
         .subscribe(onNext -> latch1.countDown(), System.err::println);
 
@@ -111,8 +110,7 @@ public void test_remote_node_died_many_never() throws Exception {
     sub1.set(serviceCall.requestMany(JUST_MANY_NEVER).doOnError(exceptionHolder::set).subscribe());
 
     gateway
-        .discovery()
-        .listen()
+        .listenDiscovery()
         .filter(ServiceDiscoveryEvent::isEndpointRemoved)
         .subscribe(onNext -> latch1.countDown(), System.err::println);
 
@@ -144,8 +142,7 @@ public void test_remote_node_died_many_then_never() throws Exception {
             .subscribe());
 
     gateway
-        .discovery()
-        .listen()
+        .listenDiscovery()
         .filter(ServiceDiscoveryEvent::isEndpointRemoved)
         .subscribe(onNext -> latch1.countDown(), System.err::println);