Add support for ReactiveHealthIndicatorRegistry

This commit updates the initial proposal to add support for reactive
use cases as well. A reactive application can use
ReactiveHealthIndicatorRegistry as an alternative to
HealthIndicatorRegistry.

Closes gh-4965

Author: snicoll

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/health/CompositeReactiveHealthIndicatorConfiguration.java

@@ -20,8 +20,10 @@
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.actuate.health.CompositeReactiveHealthIndicator;
+import org.springframework.boot.actuate.health.DefaultReactiveHealthIndicatorRegistry;
 import org.springframework.boot.actuate.health.HealthAggregator;
 import org.springframework.boot.actuate.health.ReactiveHealthIndicator;
+import org.springframework.boot.actuate.health.ReactiveHealthIndicatorRegistry;
 import org.springframework.core.ResolvableType;
 
 /**
@@ -41,11 +43,10 @@ protected ReactiveHealthIndicator createHealthIndicator(Map<String, S> beans) {
 		if (beans.size() == 1) {
 			return createHealthIndicator(beans.values().iterator().next());
 		}
-		CompositeReactiveHealthIndicator composite = new CompositeReactiveHealthIndicator(
-				this.healthAggregator);
-		beans.forEach((name, source) -> composite.addHealthIndicator(name,
+		ReactiveHealthIndicatorRegistry registry = new DefaultReactiveHealthIndicatorRegistry();
+		beans.forEach((name, source) -> registry.register(name,
 				createHealthIndicator(source)));
-		return composite;
+		return new CompositeReactiveHealthIndicator(this.healthAggregator, registry);
 	}
 
 	@SuppressWarnings("unchecked")

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/health/HealthEndpointWebExtensionConfiguration.java

@@ -16,23 +16,21 @@
 
 package org.springframework.boot.actuate.autoconfigure.health;
 
-import java.util.Collections;
-import java.util.Map;
-
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.actuate.autoconfigure.endpoint.condition.ConditionalOnEnabledEndpoint;
-import org.springframework.boot.actuate.health.CompositeReactiveHealthIndicatorFactory;
+import org.springframework.boot.actuate.health.CompositeReactiveHealthIndicator;
 import org.springframework.boot.actuate.health.HealthAggregator;
 import org.springframework.boot.actuate.health.HealthEndpoint;
 import org.springframework.boot.actuate.health.HealthEndpointWebExtension;
-import org.springframework.boot.actuate.health.HealthIndicator;
 import org.springframework.boot.actuate.health.HealthStatusHttpMapper;
 import org.springframework.boot.actuate.health.HealthWebEndpointResponseMapper;
 import org.springframework.boot.actuate.health.OrderedHealthAggregator;
 import org.springframework.boot.actuate.health.ReactiveHealthEndpointWebExtension;
 import org.springframework.boot.actuate.health.ReactiveHealthIndicator;
+import org.springframework.boot.actuate.health.ReactiveHealthIndicatorRegistry;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnSingleCandidate;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication.Type;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
@@ -70,19 +68,16 @@ public HealthWebEndpointResponseMapper healthWebEndpointResponseMapper(
 
 	@Configuration
 	@ConditionalOnWebApplication(type = Type.REACTIVE)
+	@ConditionalOnSingleCandidate(ReactiveHealthIndicatorRegistry.class)
 	static class ReactiveWebHealthConfiguration {
 
 		private final ReactiveHealthIndicator reactiveHealthIndicator;
 
 		ReactiveWebHealthConfiguration(ObjectProvider<HealthAggregator> healthAggregator,
-				ObjectProvider<Map<String, ReactiveHealthIndicator>> reactiveHealthIndicators,
-				ObjectProvider<Map<String, HealthIndicator>> healthIndicators) {
-			this.reactiveHealthIndicator = new CompositeReactiveHealthIndicatorFactory()
-					.createReactiveHealthIndicator(
-							healthAggregator.getIfAvailable(OrderedHealthAggregator::new),
-							reactiveHealthIndicators
-									.getIfAvailable(Collections::emptyMap),
-							healthIndicators.getIfAvailable(Collections::emptyMap));
+				ReactiveHealthIndicatorRegistry registry) {
+			this.reactiveHealthIndicator = new CompositeReactiveHealthIndicator(
+					healthAggregator.getIfAvailable(OrderedHealthAggregator::new),
+					registry);
 		}
 
 		@Bean

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/health/HealthIndicatorAutoConfiguration.java

@@ -16,13 +16,22 @@
 
 package org.springframework.boot.actuate.autoconfigure.health;
 
+import java.util.Collections;
+import java.util.Map;
+
+import reactor.core.publisher.Flux;
+
+import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.actuate.health.ApplicationHealthIndicator;
 import org.springframework.boot.actuate.health.HealthAggregator;
 import org.springframework.boot.actuate.health.HealthIndicator;
 import org.springframework.boot.actuate.health.HealthIndicatorRegistry;
 import org.springframework.boot.actuate.health.OrderedHealthAggregator;
 import org.springframework.boot.actuate.health.ReactiveHealthIndicator;
+import org.springframework.boot.actuate.health.ReactiveHealthIndicatorRegistry;
+import org.springframework.boot.actuate.health.ReactiveHealthIndicatorRegistryFactory;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.ApplicationContext;
@@ -71,4 +80,20 @@ public HealthIndicatorRegistry healthIndicatorRegistry(
 		return HealthIndicatorRegistryBeans.get(applicationContext);
 	}
 
+	@Configuration
+	@ConditionalOnClass(Flux.class)
+	static class ReactiveHealthIndicatorConfiguration {
+
+		@Bean
+		@ConditionalOnMissingBean
+		public ReactiveHealthIndicatorRegistry reactiveHealthIndicatorRegistry(
+				ObjectProvider<Map<String, ReactiveHealthIndicator>> reactiveHealthIndicators,
+				ObjectProvider<Map<String, HealthIndicator>> healthIndicators) {
+			return new ReactiveHealthIndicatorRegistryFactory().createReactiveHealthIndicatorRegistry(
+					reactiveHealthIndicators.getIfAvailable(Collections::emptyMap),
+					healthIndicators.getIfAvailable(Collections::emptyMap));
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/health/HealthIndicatorBeansReactiveComposite.java

@@ -28,6 +28,7 @@
 import org.springframework.boot.actuate.health.HealthWebEndpointResponseMapper;
 import org.springframework.boot.actuate.health.ReactiveHealthEndpointWebExtension;
 import org.springframework.boot.actuate.health.ReactiveHealthIndicator;
+import org.springframework.boot.actuate.health.ReactiveHealthIndicatorRegistry;
 import org.springframework.boot.test.context.runner.ReactiveWebApplicationContextRunner;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -217,6 +218,24 @@ public void roleCanBeCustomized() {
 				});
 	}
 
+	@Test
+	public void registryCanBeAltered() {
+		this.contextRunner
+				.withUserConfiguration(HealthIndicatorsConfiguration.class)
+				.withPropertyValues("management.endpoint.health.show-details=always")
+				.run((context) -> {
+					ReactiveHealthIndicatorRegistry registry = context.getBean(
+							ReactiveHealthIndicatorRegistry.class);
+					ReactiveHealthEndpointWebExtension extension = context
+							.getBean(ReactiveHealthEndpointWebExtension.class);
+					assertThat(extension.health(null).block().getBody().getDetails())
+							.containsOnlyKeys("application", "first", "second");
+					assertThat(registry.unregister("second")).isNotNull();
+					assertThat(extension.health(null).block().getBody().getDetails())
+							.containsKeys("application", "first");
+				});
+	}
+
 	@Configuration
 	static class HealthIndicatorsConfiguration {
 

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/health/ReactiveHealthEndpointWebExtensionTests.java

@@ -25,8 +25,6 @@
 import reactor.core.publisher.Mono;
 import reactor.util.function.Tuple2;
 
-import org.springframework.util.Assert;
-
 /**
  * {@link ReactiveHealthIndicator} that returns health indications from all registered
  * delegates. Provides an alternative {@link Health} for a delegate that reaches a
@@ -37,7 +35,7 @@
  */
 public class CompositeReactiveHealthIndicator implements ReactiveHealthIndicator {
 
-	private final Map<String, ReactiveHealthIndicator> indicators;
+	private final ReactiveHealthIndicatorRegistry registry;
 
 	private final HealthAggregator healthAggregator;
 
@@ -47,15 +45,42 @@ public class CompositeReactiveHealthIndicator implements ReactiveHealthIndicator
 
 	private final Function<Mono<Health>, Mono<Health>> timeoutCompose;
 
+	/**
+	 * Create a new {@link CompositeReactiveHealthIndicator}.
+	 * @param healthAggregator the health aggregator
+	 * @deprecated since 2.1.0 in favour of
+	 * {@link #CompositeReactiveHealthIndicator(HealthAggregator, ReactiveHealthIndicatorRegistry)}
+	 */
+	@Deprecated
 	public CompositeReactiveHealthIndicator(HealthAggregator healthAggregator) {
 		this(healthAggregator, new LinkedHashMap<>());
 	}
 
+	/**
+	 * Create a new {@link CompositeReactiveHealthIndicator} from the specified
+	 * indicators.
+	 * @param healthAggregator the health aggregator
+	 * @param indicators a map of {@link ReactiveHealthIndicator HealthIndicators} with
+	 * the key being used as an indicator name.
+	 * @deprecated since 2.1.0 in favour of
+	 * {@link #CompositeReactiveHealthIndicator(HealthAggregator, ReactiveHealthIndicatorRegistry)}
+	 */
+	@Deprecated
 	public CompositeReactiveHealthIndicator(HealthAggregator healthAggregator,
 			Map<String, ReactiveHealthIndicator> indicators) {
-		Assert.notNull(healthAggregator, "HealthAggregator must not be null");
-		Assert.notNull(indicators, "Indicators must not be null");
-		this.indicators = new LinkedHashMap<>(indicators);
+		this(healthAggregator, new DefaultReactiveHealthIndicatorRegistry(indicators));
+
+	}
+
+	/**
+	 * Create a new {@link CompositeReactiveHealthIndicator} from the indicators in the
+	 * given {@code registry}.
+	 * @param healthAggregator the health aggregator
+	 * @param registry the registry of {@link ReactiveHealthIndicator HealthIndicators}.
+	 */
+	public CompositeReactiveHealthIndicator(HealthAggregator healthAggregator,
+			ReactiveHealthIndicatorRegistry registry) {
+		this.registry = registry;
 		this.healthAggregator = healthAggregator;
 		this.timeoutCompose = (mono) -> (this.timeout != null ? mono.timeout(
 				Duration.ofMillis(this.timeout), Mono.just(this.timeoutHealth)) : mono);
@@ -66,10 +91,15 @@ public CompositeReactiveHealthIndicator(HealthAggregator healthAggregator,
 	 * @param name the name of the health indicator
 	 * @param indicator the health indicator to add
 	 * @return this instance
+	 * @throws IllegalStateException if an indicator with the given {@code name}
+	 * is already registered.
+	 * @deprecated since 2.1.0 in favour of
+	 * {@link ReactiveHealthIndicatorRegistry#register(String, ReactiveHealthIndicator)}
 	 */
+	@Deprecated
 	public CompositeReactiveHealthIndicator addHealthIndicator(String name,
 			ReactiveHealthIndicator indicator) {
-		this.indicators.put(name, indicator);
+		this.registry.register(name, indicator);
 		return this;
 	}
 
@@ -92,7 +122,7 @@ public CompositeReactiveHealthIndicator timeoutStrategy(long timeout,
 
 	@Override
 	public Mono<Health> health() {
-		return Flux.fromIterable(this.indicators.entrySet())
+		return Flux.fromIterable(this.registry.getAll().entrySet())
 				.flatMap((entry) -> Mono.zip(Mono.just(entry.getKey()),
 						entry.getValue().health().compose(this.timeoutCompose)))
 				.collectMap(Tuple2::getT1, Tuple2::getT2)

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/health/CompositeReactiveHealthIndicator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -16,19 +16,20 @@
 
 package org.springframework.boot.actuate.health;
 
-import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.function.Function;
 
 import org.springframework.util.Assert;
-import org.springframework.util.ObjectUtils;
 
 /**
  * Factory to create a {@link CompositeReactiveHealthIndicator}.
  *
  * @author Stephane Nicoll
  * @since 2.0.0
+ * @deprecated since 2.1.0 in favor of
+ * {@link CompositeReactiveHealthIndicator#CompositeReactiveHealthIndicator(HealthAggregator, ReactiveHealthIndicatorRegistry)}
  */
+@Deprecated
 public class CompositeReactiveHealthIndicatorFactory {
 
 	private final Function<String, String> healthIndicatorNameFactory;
@@ -62,30 +63,11 @@ public CompositeReactiveHealthIndicator createReactiveHealthIndicator(
 		Assert.notNull(healthAggregator, "HealthAggregator must not be null");
 		Assert.notNull(reactiveHealthIndicators,
 				"ReactiveHealthIndicators must not be null");
-		CompositeReactiveHealthIndicator healthIndicator = new CompositeReactiveHealthIndicator(
-				healthAggregator);
-		merge(reactiveHealthIndicators, healthIndicators)
-				.forEach((beanName, indicator) -> {
-					String name = this.healthIndicatorNameFactory.apply(beanName);
-					healthIndicator.addHealthIndicator(name, indicator);
-				});
-		return healthIndicator;
-	}
-
-	private Map<String, ReactiveHealthIndicator> merge(
-			Map<String, ReactiveHealthIndicator> reactiveHealthIndicators,
-			Map<String, HealthIndicator> healthIndicators) {
-		if (ObjectUtils.isEmpty(healthIndicators)) {
-			return reactiveHealthIndicators;
-		}
-		Map<String, ReactiveHealthIndicator> allIndicators = new LinkedHashMap<>(
-				reactiveHealthIndicators);
-		healthIndicators.forEach((beanName, indicator) -> {
-			String name = this.healthIndicatorNameFactory.apply(beanName);
-			allIndicators.computeIfAbsent(name,
-					(n) -> new HealthIndicatorReactiveAdapter(indicator));
-		});
-		return allIndicators;
+		ReactiveHealthIndicatorRegistryFactory factory = new ReactiveHealthIndicatorRegistryFactory(
+				this.healthIndicatorNameFactory);
+		return new CompositeReactiveHealthIndicator(healthAggregator,
+				factory.createReactiveHealthIndicatorRegistry(reactiveHealthIndicators,
+						healthIndicators));
 	}
 
 }