feat(#2528): implement instance filter (#3580)

spring-boot-admin-server-cloud/src/test/java/de/codecentric/boot/admin/server/cloud/discovery/InstanceDiscoveryListenerTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2023 the original author or authors.
+ * Copyright 2014-2024 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.
@@ -62,7 +62,7 @@ public class InstanceDiscoveryListenerTest {
 	public void setup() {
 		this.discovery = mock(DiscoveryClient.class);
 		InstanceRepository repository = new EventsourcingInstanceRepository(new InMemoryEventStore());
-		this.registry = spy(new InstanceRegistry(repository, new HashingInstanceUrlIdGenerator()));
+		this.registry = spy(new InstanceRegistry(repository, new HashingInstanceUrlIdGenerator(), (instance) -> true));
 		this.listener = new InstanceDiscoveryListener(this.discovery, this.registry, repository);
 	}
 

spring-boot-admin-server/src/main/java/de/codecentric/boot/admin/server/config/AdminServerAutoConfiguration.java

@@ -44,6 +44,7 @@
 import de.codecentric.boot.admin.server.services.HashingInstanceUrlIdGenerator;
 import de.codecentric.boot.admin.server.services.InfoUpdateTrigger;
 import de.codecentric.boot.admin.server.services.InfoUpdater;
+import de.codecentric.boot.admin.server.services.InstanceFilter;
 import de.codecentric.boot.admin.server.services.InstanceIdGenerator;
 import de.codecentric.boot.admin.server.services.InstanceRegistry;
 import de.codecentric.boot.admin.server.services.StatusUpdateTrigger;
@@ -69,11 +70,17 @@ public AdminServerAutoConfiguration(AdminServerProperties adminServerProperties)
 		this.adminServerProperties = adminServerProperties;
 	}
 
+	@Bean
+	@ConditionalOnMissingBean
+	public InstanceFilter instanceFilter() {
+		return (instance) -> true;
+	}
+
 	@Bean
 	@ConditionalOnMissingBean
 	public InstanceRegistry instanceRegistry(InstanceRepository instanceRepository,
-			InstanceIdGenerator instanceIdGenerator) {
-		return new InstanceRegistry(instanceRepository, instanceIdGenerator);
+			InstanceIdGenerator instanceIdGenerator, InstanceFilter instanceFilter) {
+		return new InstanceRegistry(instanceRepository, instanceIdGenerator, instanceFilter);
 	}
 
 	@Bean

spring-boot-admin-server/src/main/java/de/codecentric/boot/admin/server/services/InstanceFilter.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2014-2024 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
+ *
+ *     https://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 de.codecentric.boot.admin.server.services;
+
+import de.codecentric.boot.admin.server.domain.entities.Instance;
+
+/**
+ * Interface that is applied to InstanceRegistry and returns Instances matching the
+ * filter, only. Default implementation is to return all instances.
+ *
+ * @author dzahbarov
+ * @see de.codecentric.boot.admin.server.config.AdminServerAutoConfiguration#instanceFilter()
+ */
+@FunctionalInterface
+public interface InstanceFilter {
+
+	boolean filter(Instance instance);
+
+}

spring-boot-admin-server/src/main/java/de/codecentric/boot/admin/server/services/InstanceRegistry.java

@@ -27,18 +27,21 @@
 
 /**
  * Registry for all application instances that should be managed/administrated by the
- * Spring Boot Admin server. Backed by an InstanceRepository for persistence and an
- * InstanceIdGenerator for id generation.
+ * Spring Boot Admin server. Backed by an InstanceRepository for persistence, an
+ * InstanceIdGenerator for id generation and InstanceFilter for instance filtering.
  */
 public class InstanceRegistry {
 
 	private final InstanceRepository repository;
 
 	private final InstanceIdGenerator generator;
 
-	public InstanceRegistry(InstanceRepository repository, InstanceIdGenerator generator) {
+	private final InstanceFilter filter;
+
+	public InstanceRegistry(InstanceRepository repository, InstanceIdGenerator generator, InstanceFilter filter) {
 		this.repository = repository;
 		this.generator = generator;
+		this.filter = filter;
 	}
 
 	/**
@@ -59,20 +62,20 @@ public Mono<InstanceId> register(Registration registration) {
 	}
 
 	/**
-	 * Get a list of all registered instances.
-	 * @return list of all instances.
+	 * Get a list of all registered instances that satisfy the filter.
+	 * @return list of all instances satisfying the filter.
 	 */
 	public Flux<Instance> getInstances() {
-		return repository.findAll();
+		return repository.findAll().filter(filter::filter);
 	}
 
 	/**
-	 * Get a list of all registered application instances.
+	 * Get a list of all registered application instances that satisfy the filter.
 	 * @param name the name to search for.
-	 * @return list of instances for the given application
+	 * @return list of instances for the given application that satisfy the filter.
 	 */
 	public Flux<Instance> getInstances(String name) {
-		return repository.findByName(name);
+		return repository.findByName(name).filter(filter::filter);
 	}
 
 	/**
@@ -81,7 +84,7 @@ public Flux<Instance> getInstances(String name) {
 	 * @return a Mono with the Instance.
 	 */
 	public Mono<Instance> getInstance(InstanceId id) {
-		return repository.find(id);
+		return repository.find(id).filter(filter::filter);
 	}
 
 	/**

spring-boot-admin-server/src/test/java/de/codecentric/boot/admin/server/services/InstanceRegistryTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2023 the original author or authors.
+ * Copyright 2014-2024 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.
@@ -17,6 +17,7 @@
 package de.codecentric.boot.admin.server.services;
 
 import java.util.ArrayList;
+import java.util.Map;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -47,7 +48,10 @@ public class InstanceRegistryTest {
 	public void setUp() {
 		repository = new EventsourcingInstanceRepository(new InMemoryEventStore());
 		idGenerator = new HashingInstanceUrlIdGenerator();
-		registry = new InstanceRegistry(repository, idGenerator);
+		registry = new InstanceRegistry(repository, idGenerator, (instance) -> {
+			Map<String, String> metadata = instance.getRegistration().getMetadata();
+			return !metadata.containsKey("displayed") || !metadata.get("displayed").equals("false");
+		});
 	}
 
 	@Test
@@ -118,4 +122,19 @@ public void findByName() {
 			.verifyComplete();
 	}
 
+	@Test
+	public void findByNameAndFilter() {
+		InstanceId id1 = registry.register(Registration.create("abc", "http://localhost:8080/health").build()).block();
+		registry
+			.register(Registration.create("abc", "http://localhost:8081/health").metadata("displayed", "false").build())
+			.block();
+
+		StepVerifier.create(registry.getInstances("abc"))
+			.recordWith(ArrayList::new)
+			.thenConsumeWhile((a) -> true)
+			.consumeRecordedWith(
+					(applications) -> assertThat(applications.stream().map(Instance::getId)).containsExactly(id1))
+			.verifyComplete();
+	}
+
 }