Add HealthEndpointGroupsRegistry and its Customizer

Prior to this commit, `HealthContributor` would be exposed under the
main `HealthEndpoint` and subgroups, `HealthEndpointGroups`. Groups are
driven by configuration properties and there was no way to contribute
programmatically new groups.

This commit introduces the `HealthEndpointGroupsRegistry` (a mutable
version of `HealthEndpointGroups`) and a
`HealthEndpointGroupsRegistryCustomizer`. This allows configurations to
add/remove groups during Actuator auto-configuration.

Closes gh-20554

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

@@ -22,6 +22,7 @@ import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.function.Consumer;
 import java.util.function.Predicate;
 import java.util.function.Supplier;
 
@@ -31,10 +32,12 @@ import org.springframework.beans.factory.ListableBeanFactory;
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.beans.factory.annotation.BeanFactoryAnnotationUtils;
 import org.springframework.boot.actuate.autoconfigure.health.HealthEndpointProperties.Group;
-import org.springframework.boot.actuate.autoconfigure.health.HealthProperties.Show;
 import org.springframework.boot.actuate.autoconfigure.health.HealthProperties.Status;
 import org.springframework.boot.actuate.health.HealthEndpointGroup;
+import org.springframework.boot.actuate.health.HealthEndpointGroup.Show;
+import org.springframework.boot.actuate.health.HealthEndpointGroupConfigurer;
 import org.springframework.boot.actuate.health.HealthEndpointGroups;
+import org.springframework.boot.actuate.health.HealthEndpointGroupsRegistry;
 import org.springframework.boot.actuate.health.HttpCodeStatusMapper;
 import org.springframework.boot.actuate.health.SimpleHttpCodeStatusMapper;
 import org.springframework.boot.actuate.health.SimpleStatusAggregator;
@@ -45,71 +48,113 @@ import org.springframework.util.CollectionUtils;
 import org.springframework.util.ObjectUtils;
 
 /**
- * Auto-configured {@link HealthEndpointGroups}.
+ * Auto-configured {@link HealthEndpointGroupsRegistry}.
  *
  * @author Phillip Webb
+ * @author Brian Clozel
  */
-class AutoConfiguredHealthEndpointGroups implements HealthEndpointGroups {
+class AutoConfiguredHealthEndpointGroupsRegistry implements HealthEndpointGroupsRegistry {
 
 	private static Predicate<String> ALL = (name) -> true;
 
-	private final HealthEndpointGroup primaryGroup;
+	private final StatusAggregator defaultStatusAggregator;
+
+	private final HttpCodeStatusMapper defaultHttpCodeStatusMapper;
+
+	private final Show defaultShowComponents;
+
+	private final Show defaultShowDetails;
+
+	private final Set<String> defaultRoles;
+
+	private HealthEndpointGroup primaryGroup;
 
 	private final Map<String, HealthEndpointGroup> groups;
 
 	/**
-	 * Create a new {@link AutoConfiguredHealthEndpointGroups} instance.
+	 * Create a new {@link AutoConfiguredHealthEndpointGroupsRegistry} instance.
 	 * @param applicationContext the application context used to check for override beans
 	 * @param properties the health endpoint properties
 	 */
-	AutoConfiguredHealthEndpointGroups(ApplicationContext applicationContext, HealthEndpointProperties properties) {
+	AutoConfiguredHealthEndpointGroupsRegistry(ApplicationContext applicationContext,
+			HealthEndpointProperties properties) {
 		ListableBeanFactory beanFactory = (applicationContext instanceof ConfigurableApplicationContext)
 				? ((ConfigurableApplicationContext) applicationContext).getBeanFactory() : applicationContext;
-		Show showComponents = properties.getShowComponents();
-		Show showDetails = properties.getShowDetails();
-		Set<String> roles = properties.getRoles();
+		this.defaultShowComponents = convertVisibility(properties.getShowComponents());
+		this.defaultShowDetails = convertVisibility(properties.getShowDetails());
+		this.defaultRoles = properties.getRoles();
+
 		StatusAggregator statusAggregator = getNonQualifiedBean(beanFactory, StatusAggregator.class);
 		if (statusAggregator == null) {
 			statusAggregator = new SimpleStatusAggregator(properties.getStatus().getOrder());
 		}
+		this.defaultStatusAggregator = statusAggregator;
+
 		HttpCodeStatusMapper httpCodeStatusMapper = getNonQualifiedBean(beanFactory, HttpCodeStatusMapper.class);
 		if (httpCodeStatusMapper == null) {
 			httpCodeStatusMapper = new SimpleHttpCodeStatusMapper(properties.getStatus().getHttpMapping());
 		}
-		this.primaryGroup = new AutoConfiguredHealthEndpointGroup(ALL, statusAggregator, httpCodeStatusMapper,
-				showComponents, showDetails, roles);
-		this.groups = createGroups(properties.getGroup(), beanFactory, statusAggregator, httpCodeStatusMapper,
-				showComponents, showDetails, roles);
+		this.defaultHttpCodeStatusMapper = httpCodeStatusMapper;
+
+		this.primaryGroup = new DefaultHealthEndpointGroup(ALL, statusAggregator, httpCodeStatusMapper,
+				this.defaultShowComponents, this.defaultShowDetails, this.defaultRoles);
+
+		this.groups = createGroups(properties.getGroup(), beanFactory);
+	}
+
+	@Override
+	public HealthEndpointGroupsRegistry add(String groupName, Consumer<HealthEndpointGroupConfigurer> consumer) {
+		DefaultHealthEndpointGroupConfigurer groupConfigurer = new DefaultHealthEndpointGroupConfigurer(
+				this.defaultStatusAggregator, this.defaultHttpCodeStatusMapper, this.defaultShowComponents,
+				this.defaultShowDetails, this.defaultRoles);
+		consumer.accept(groupConfigurer);
+		this.groups.put(groupName, groupConfigurer.toHealthEndpointGroup());
+		return this;
+	}
+
+	@Override
+	public HealthEndpointGroupsRegistry remove(String groupName) {
+		this.groups.remove(groupName);
+		return this;
 	}
 
-	private Map<String, HealthEndpointGroup> createGroups(Map<String, Group> groupProperties, BeanFactory beanFactory,
-			StatusAggregator defaultStatusAggregator, HttpCodeStatusMapper defaultHttpCodeStatusMapper,
-			Show defaultShowComponents, Show defaultShowDetails, Set<String> defaultRoles) {
+	@Override
+	public HealthEndpointGroups toGroups() {
+		return HealthEndpointGroups.of(this.primaryGroup, Collections.unmodifiableMap(this.groups));
+	}
+
+	private Map<String, HealthEndpointGroup> createGroups(Map<String, Group> groupProperties, BeanFactory beanFactory) {
 		Map<String, HealthEndpointGroup> groups = new LinkedHashMap<>();
-		groupProperties.forEach((groupName, group) -> {
-			Status status = group.getStatus();
-			Show showComponents = (group.getShowComponents() != null) ? group.getShowComponents()
-					: defaultShowComponents;
-			Show showDetails = (group.getShowDetails() != null) ? group.getShowDetails() : defaultShowDetails;
-			Set<String> roles = !CollectionUtils.isEmpty(group.getRoles()) ? group.getRoles() : defaultRoles;
-			StatusAggregator statusAggregator = getQualifiedBean(beanFactory, StatusAggregator.class, groupName, () -> {
-				if (!CollectionUtils.isEmpty(status.getOrder())) {
-					return new SimpleStatusAggregator(status.getOrder());
-				}
-				return defaultStatusAggregator;
-			});
-			HttpCodeStatusMapper httpCodeStatusMapper = getQualifiedBean(beanFactory, HttpCodeStatusMapper.class,
-					groupName, () -> {
-						if (!CollectionUtils.isEmpty(status.getHttpMapping())) {
-							return new SimpleHttpCodeStatusMapper(status.getHttpMapping());
-						}
-						return defaultHttpCodeStatusMapper;
-					});
-			Predicate<String> members = new IncludeExcludeGroupMemberPredicate(group.getInclude(), group.getExclude());
-			groups.put(groupName, new AutoConfiguredHealthEndpointGroup(members, statusAggregator, httpCodeStatusMapper,
-					showComponents, showDetails, roles));
+		groupProperties
+				.forEach((groupName, group) -> groups.put(groupName, createGroup(groupName, group, beanFactory)));
+		return groups;
+	}
+
+	private HealthEndpointGroup createGroup(String groupName, Group groupProperties, BeanFactory beanFactory) {
+		Status status = groupProperties.getStatus();
+		Show showComponents = (groupProperties.getShowComponents() != null)
+				? convertVisibility(groupProperties.getShowComponents()) : this.defaultShowComponents;
+		Show showDetails = (groupProperties.getShowDetails() != null)
+				? convertVisibility(groupProperties.getShowDetails()) : this.defaultShowDetails;
+		Set<String> roles = !CollectionUtils.isEmpty(groupProperties.getRoles()) ? groupProperties.getRoles()
+				: this.defaultRoles;
+		StatusAggregator statusAggregator = getQualifiedBean(beanFactory, StatusAggregator.class, groupName, () -> {
+			if (!CollectionUtils.isEmpty(status.getOrder())) {
+				return new SimpleStatusAggregator(status.getOrder());
+			}
+			return this.defaultStatusAggregator;
 		});
-		return Collections.unmodifiableMap(groups);
+		HttpCodeStatusMapper httpCodeStatusMapper = getQualifiedBean(beanFactory, HttpCodeStatusMapper.class, groupName,
+				() -> {
+					if (!CollectionUtils.isEmpty(status.getHttpMapping())) {
+						return new SimpleHttpCodeStatusMapper(status.getHttpMapping());
+					}
+					return this.defaultHttpCodeStatusMapper;
+				});
+		Predicate<String> members = new IncludeExcludeGroupMemberPredicate(groupProperties.getInclude(),
+				groupProperties.getExclude());
+		return new DefaultHealthEndpointGroup(members, statusAggregator, httpCodeStatusMapper, showComponents,
+				showDetails, roles);
 	}
 
 	private <T> T getNonQualifiedBean(ListableBeanFactory beanFactory, Class<T> type) {
@@ -140,6 +185,21 @@ class AutoConfiguredHealthEndpointGroups implements HealthEndpointGroups {
 		}
 	}
 
+	private Show convertVisibility(HealthProperties.Show show) {
+		if (show == null) {
+			return null;
+		}
+		switch (show) {
+		case ALWAYS:
+			return Show.ALWAYS;
+		case NEVER:
+			return Show.NEVER;
+		case WHEN_AUTHORIZED:
+			return Show.WHEN_AUTHORIZED;
+		}
+		throw new IllegalStateException("Unsupported 'show' value " + show);
+	}
+
 	@Override
 	public HealthEndpointGroup getPrimary() {
 		return this.primaryGroup;

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

@@ -20,7 +20,6 @@ import java.security.Principal;
 import java.util.Collection;
 import java.util.function.Predicate;
 
-import org.springframework.boot.actuate.autoconfigure.health.HealthProperties.Show;
 import org.springframework.boot.actuate.endpoint.SecurityContext;
 import org.springframework.boot.actuate.health.HealthEndpointGroup;
 import org.springframework.boot.actuate.health.HttpCodeStatusMapper;
@@ -31,12 +30,12 @@ import org.springframework.util.ClassUtils;
 import org.springframework.util.CollectionUtils;
 
 /**
- * Auto-configured {@link HealthEndpointGroup} backed by {@link HealthProperties}.
+ * Auto-configured {@link HealthEndpointGroup}.
  *
  * @author Phillip Webb
  * @author Andy Wilkinson
  */
-class AutoConfiguredHealthEndpointGroup implements HealthEndpointGroup {
+class DefaultHealthEndpointGroup implements HealthEndpointGroup {
 
 	private final Predicate<String> members;
 
@@ -51,7 +50,7 @@ class AutoConfiguredHealthEndpointGroup implements HealthEndpointGroup {
 	private final Collection<String> roles;
 
 	/**
-	 * Create a new {@link AutoConfiguredHealthEndpointGroup} instance.
+	 * Create a new {@link DefaultHealthEndpointGroup} instance.
 	 * @param members a predicate used to test for group membership
 	 * @param statusAggregator the status aggregator to use
 	 * @param httpCodeStatusMapper the HTTP code status mapper to use
@@ -59,7 +58,7 @@ class AutoConfiguredHealthEndpointGroup implements HealthEndpointGroup {
 	 * @param showDetails the show details setting
 	 * @param roles the roles to match
 	 */
-	AutoConfiguredHealthEndpointGroup(Predicate<String> members, StatusAggregator statusAggregator,
+	DefaultHealthEndpointGroup(Predicate<String> members, StatusAggregator statusAggregator,
 			HttpCodeStatusMapper httpCodeStatusMapper, Show showComponents, Show showDetails,
 			Collection<String> roles) {
 		this.members = members;

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

@@ -0,0 +1,110 @@
+/*
+ * Copyright 2012-2020 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 org.springframework.boot.actuate.autoconfigure.health;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.springframework.boot.actuate.health.HealthEndpointGroup;
+import org.springframework.boot.actuate.health.HealthEndpointGroup.Show;
+import org.springframework.boot.actuate.health.HealthEndpointGroupConfigurer;
+import org.springframework.boot.actuate.health.HttpCodeStatusMapper;
+import org.springframework.boot.actuate.health.StatusAggregator;
+
+/**
+ * Mutable {@link HealthEndpointGroupConfigurer configurer} for
+ * {@link HealthEndpointGroup}.
+ *
+ * @author Brian Clozel
+ */
+class DefaultHealthEndpointGroupConfigurer implements HealthEndpointGroupConfigurer {
+
+	Set<String> includedIndicators;
+
+	Set<String> excludedIndicators;
+
+	private StatusAggregator statusAggregator;
+
+	private HttpCodeStatusMapper httpCodeStatusMapper;
+
+	private Show showComponents;
+
+	private Show showDetails;
+
+	private Set<String> roles;
+
+	DefaultHealthEndpointGroupConfigurer(StatusAggregator defaultStatusAggregator,
+			HttpCodeStatusMapper defaultHttpCodeStatusMapper, Show defaultShowComponents, Show defaultShowDetails,
+			Set<String> defaultRoles) {
+		this.statusAggregator = defaultStatusAggregator;
+		this.httpCodeStatusMapper = defaultHttpCodeStatusMapper;
+		this.showComponents = defaultShowComponents;
+		this.showDetails = defaultShowDetails;
+		this.roles = new HashSet<>(defaultRoles);
+	}
+
+	@Override
+	public HealthEndpointGroupConfigurer include(String... indicators) {
+		this.includedIndicators = new HashSet<>(Arrays.asList(indicators));
+		return this;
+	}
+
+	@Override
+	public HealthEndpointGroupConfigurer exclude(String... exclude) {
+		this.excludedIndicators = new HashSet<>(Arrays.asList(exclude));
+		return this;
+	}
+
+	@Override
+	public HealthEndpointGroupConfigurer statusAggregator(StatusAggregator statusAggregator) {
+		this.statusAggregator = statusAggregator;
+		return this;
+	}
+
+	@Override
+	public HealthEndpointGroupConfigurer httpCodeStatusMapper(HttpCodeStatusMapper httpCodeStatusMapper) {
+		this.httpCodeStatusMapper = httpCodeStatusMapper;
+		return this;
+	}
+
+	@Override
+	public HealthEndpointGroupConfigurer showComponents(Show showComponents) {
+		this.showComponents = showComponents;
+		return this;
+	}
+
+	@Override
+	public HealthEndpointGroupConfigurer showDetails(Show showDetails) {
+		this.showDetails = showDetails;
+		return this;
+	}
+
+	@Override
+	public HealthEndpointGroupConfigurer roles(String... roles) {
+		this.roles = new HashSet<>(Arrays.asList(roles));
+		return this;
+	}
+
+	HealthEndpointGroup toHealthEndpointGroup() {
+		IncludeExcludeGroupMemberPredicate predicate = new IncludeExcludeGroupMemberPredicate(this.includedIndicators,
+				this.excludedIndicators);
+		return new DefaultHealthEndpointGroup(predicate, this.statusAggregator, this.httpCodeStatusMapper,
+				this.showComponents, this.showDetails, this.roles);
+	}
+
+}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -21,6 +21,7 @@ import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.Map;
 
+import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.actuate.health.CompositeHealthContributor;
 import org.springframework.boot.actuate.health.CompositeReactiveHealthContributor;
 import org.springframework.boot.actuate.health.Health;
@@ -28,6 +29,7 @@ import org.springframework.boot.actuate.health.HealthContributor;
 import org.springframework.boot.actuate.health.HealthContributorRegistry;
 import org.springframework.boot.actuate.health.HealthEndpoint;
 import org.springframework.boot.actuate.health.HealthEndpointGroups;
+import org.springframework.boot.actuate.health.HealthEndpointGroupsRegistryCustomizer;
 import org.springframework.boot.actuate.health.HealthIndicator;
 import org.springframework.boot.actuate.health.HttpCodeStatusMapper;
 import org.springframework.boot.actuate.health.NamedContributor;
@@ -66,8 +68,11 @@ class HealthEndpointConfiguration {
 	@Bean
 	@ConditionalOnMissingBean
 	HealthEndpointGroups healthEndpointGroups(ApplicationContext applicationContext,
-			HealthEndpointProperties properties) {
-		return new AutoConfiguredHealthEndpointGroups(applicationContext, properties);
+			HealthEndpointProperties properties, ObjectProvider<HealthEndpointGroupsRegistryCustomizer> customizers) {
+		AutoConfiguredHealthEndpointGroupsRegistry registry = new AutoConfiguredHealthEndpointGroupsRegistry(
+				applicationContext, properties);
+		customizers.orderedStream().forEach((customizer) -> customizer.customize(registry));
+		return registry.toGroups();
 	}
 
 	@Bean

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

@@ -40,11 +40,11 @@ import org.springframework.context.annotation.Primary;
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
- * Tests for {@link AutoConfiguredHealthEndpointGroups}.
+ * Tests for {@link AutoConfiguredHealthEndpointGroupsRegistry}.
  *
  * @author Phillip Webb
  */
-class AutoConfiguredHealthEndpointGroupsTests {
+class AutoConfiguredHealthEndpointGroupsBuilderTests {
 
 	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
 			.withConfiguration(AutoConfigurations.of(AutoConfiguredHealthEndpointGroupsTestConfiguration.class));
@@ -313,9 +313,9 @@ class AutoConfiguredHealthEndpointGroupsTests {
 	static class AutoConfiguredHealthEndpointGroupsTestConfiguration {
 
 		@Bean
-		AutoConfiguredHealthEndpointGroups healthEndpointGroups(ConfigurableApplicationContext applicationContext,
-				HealthEndpointProperties properties) {
-			return new AutoConfiguredHealthEndpointGroups(applicationContext, properties);
+		AutoConfiguredHealthEndpointGroupsRegistry healthEndpointGroups(
+				ConfigurableApplicationContext applicationContext, HealthEndpointProperties properties) {
+			return new AutoConfiguredHealthEndpointGroupsRegistry(applicationContext, properties);
 		}
 
 	}

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

@@ -25,8 +25,8 @@ import org.junit.jupiter.api.Test;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 
-import org.springframework.boot.actuate.autoconfigure.health.HealthProperties.Show;
 import org.springframework.boot.actuate.endpoint.SecurityContext;
+import org.springframework.boot.actuate.health.HealthEndpointGroup.Show;
 import org.springframework.boot.actuate.health.HttpCodeStatusMapper;
 import org.springframework.boot.actuate.health.StatusAggregator;
 import org.springframework.security.core.Authentication;
@@ -37,11 +37,11 @@ import static org.mockito.BDDMockito.given;
 import static org.mockito.Mockito.mock;
 
 /**
- * Tests for {@link AutoConfiguredHealthEndpointGroup}.
+ * Tests for {@link DefaultHealthEndpointGroup}.
  *
  * @author Phillip Webb
  */
-class AutoConfiguredHealthEndpointGroupTests {
+class DefaultHealthEndpointGroupTests {
 
 	@Mock
 	private StatusAggregator statusAggregator;
@@ -62,7 +62,7 @@ class AutoConfiguredHealthEndpointGroupTests {
 
 	@Test
 	void isMemberWhenMemberPredicateMatchesAcceptsTrue() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> name.startsWith("a"),
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> name.startsWith("a"),
 				this.statusAggregator, this.httpCodeStatusMapper, null, Show.ALWAYS, Collections.emptySet());
 		assertThat(group.isMember("albert")).isTrue();
 		assertThat(group.isMember("arnold")).isTrue();
@@ -70,7 +70,7 @@ class AutoConfiguredHealthEndpointGroupTests {
 
 	@Test
 	void isMemberWhenMemberPredicateRejectsReturnsTrue() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> name.startsWith("a"),
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> name.startsWith("a"),
 				this.statusAggregator, this.httpCodeStatusMapper, null, Show.ALWAYS, Collections.emptySet());
 		assertThat(group.isMember("bert")).isFalse();
 		assertThat(group.isMember("ernie")).isFalse();
@@ -78,39 +78,38 @@ class AutoConfiguredHealthEndpointGroupTests {
 
 	@Test
 	void showDetailsWhenShowDetailsIsNeverReturnsFalse() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, null, Show.NEVER, Collections.emptySet());
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, null, Show.NEVER, Collections.emptySet());
 		assertThat(group.showDetails(SecurityContext.NONE)).isFalse();
 	}
 
 	@Test
 	void showDetailsWhenShowDetailsIsAlwaysReturnsTrue() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, null, Show.ALWAYS, Collections.emptySet());
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, null, Show.ALWAYS, Collections.emptySet());
 		assertThat(group.showDetails(SecurityContext.NONE)).isTrue();
 	}
 
 	@Test
 	void showDetailsWhenShowDetailsIsWhenAuthorizedAndPrincipalIsNullReturnsFalse() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, null, Show.WHEN_AUTHORIZED, Collections.emptySet());
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, null, Show.WHEN_AUTHORIZED, Collections.emptySet());
 		given(this.securityContext.getPrincipal()).willReturn(null);
 		assertThat(group.showDetails(this.securityContext)).isFalse();
 	}
 
 	@Test
 	void showDetailsWhenShowDetailsIsWhenAuthorizedAndRolesAreEmptyReturnsTrue() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, null, Show.WHEN_AUTHORIZED, Collections.emptySet());
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, null, Show.WHEN_AUTHORIZED, Collections.emptySet());
 		given(this.securityContext.getPrincipal()).willReturn(this.principal);
 		assertThat(group.showDetails(this.securityContext)).isTrue();
 	}
 
 	@Test
 	void showDetailsWhenShowDetailsIsWhenAuthorizedAndUseIsInRoleReturnsTrue() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, null, Show.WHEN_AUTHORIZED,
-				Arrays.asList("admin", "root", "bossmode"));
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, null, Show.WHEN_AUTHORIZED, Arrays.asList("admin", "root", "bossmode"));
 		given(this.securityContext.getPrincipal()).willReturn(this.principal);
 		given(this.securityContext.isUserInRole("root")).willReturn(true);
 		assertThat(group.showDetails(this.securityContext)).isTrue();
@@ -118,9 +117,8 @@ class AutoConfiguredHealthEndpointGroupTests {
 
 	@Test
 	void showDetailsWhenShowDetailsIsWhenAuthorizedAndUseIsNotInRoleReturnsFalse() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, null, Show.WHEN_AUTHORIZED,
-				Arrays.asList("admin", "rot", "bossmode"));
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, null, Show.WHEN_AUTHORIZED, Arrays.asList("admin", "rot", "bossmode"));
 		given(this.securityContext.getPrincipal()).willReturn(this.principal);
 		given(this.securityContext.isUserInRole("root")).willReturn(true);
 		assertThat(group.showDetails(this.securityContext)).isFalse();
@@ -128,9 +126,8 @@ class AutoConfiguredHealthEndpointGroupTests {
 
 	@Test
 	void showDetailsWhenShowDetailsIsWhenAuthorizedAndUserHasRightAuthorityReturnsTrue() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, null, Show.WHEN_AUTHORIZED,
-				Arrays.asList("admin", "root", "bossmode"));
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, null, Show.WHEN_AUTHORIZED, Arrays.asList("admin", "root", "bossmode"));
 		Authentication principal = mock(Authentication.class);
 		given(principal.getAuthorities())
 				.willAnswer((invocation) -> Collections.singleton(new SimpleGrantedAuthority("admin")));
@@ -140,9 +137,8 @@ class AutoConfiguredHealthEndpointGroupTests {
 
 	@Test
 	void showDetailsWhenShowDetailsIsWhenAuthorizedAndUserDoesNotHaveRightAuthoritiesReturnsFalse() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, null, Show.WHEN_AUTHORIZED,
-				Arrays.asList("admin", "rot", "bossmode"));
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, null, Show.WHEN_AUTHORIZED, Arrays.asList("admin", "rot", "bossmode"));
 		Authentication principal = mock(Authentication.class);
 		given(principal.getAuthorities())
 				.willAnswer((invocation) -> Collections.singleton(new SimpleGrantedAuthority("other")));
@@ -152,50 +148,48 @@ class AutoConfiguredHealthEndpointGroupTests {
 
 	@Test
 	void showComponentsWhenShowComponentsIsNullDelegatesToShowDetails() {
-		AutoConfiguredHealthEndpointGroup alwaysGroup = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, null, Show.ALWAYS, Collections.emptySet());
+		DefaultHealthEndpointGroup alwaysGroup = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, null, Show.ALWAYS, Collections.emptySet());
 		assertThat(alwaysGroup.showComponents(SecurityContext.NONE)).isTrue();
-		AutoConfiguredHealthEndpointGroup neverGroup = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, null, Show.NEVER, Collections.emptySet());
+		DefaultHealthEndpointGroup neverGroup = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, null, Show.NEVER, Collections.emptySet());
 		assertThat(neverGroup.showComponents(SecurityContext.NONE)).isFalse();
 	}
 
 	@Test
 	void showComponentsWhenShowComponentsIsNeverReturnsFalse() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, Show.NEVER, Show.ALWAYS, Collections.emptySet());
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, Show.NEVER, Show.ALWAYS, Collections.emptySet());
 		assertThat(group.showComponents(SecurityContext.NONE)).isFalse();
 	}
 
 	@Test
 	void showComponentsWhenShowComponentsIsAlwaysReturnsTrue() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, Show.ALWAYS, Show.NEVER, Collections.emptySet());
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, Show.ALWAYS, Show.NEVER, Collections.emptySet());
 		assertThat(group.showComponents(SecurityContext.NONE)).isTrue();
 	}
 
 	@Test
 	void showComponentsWhenShowComponentsIsWhenAuthorizedAndPrincipalIsNullReturnsFalse() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, Show.WHEN_AUTHORIZED, Show.NEVER,
-				Collections.emptySet());
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, Show.WHEN_AUTHORIZED, Show.NEVER, Collections.emptySet());
 		given(this.securityContext.getPrincipal()).willReturn(null);
 		assertThat(group.showComponents(this.securityContext)).isFalse();
 	}
 
 	@Test
 	void showComponentsWhenShowComponentsIsWhenAuthorizedAndRolesAreEmptyReturnsTrue() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, Show.WHEN_AUTHORIZED, Show.NEVER,
-				Collections.emptySet());
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, Show.WHEN_AUTHORIZED, Show.NEVER, Collections.emptySet());
 		given(this.securityContext.getPrincipal()).willReturn(this.principal);
 		assertThat(group.showComponents(this.securityContext)).isTrue();
 	}
 
 	@Test
 	void showComponentsWhenShowComponentsIsWhenAuthorizedAndUseIsInRoleReturnsTrue() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, Show.WHEN_AUTHORIZED, Show.NEVER,
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, Show.WHEN_AUTHORIZED, Show.NEVER,
 				Arrays.asList("admin", "root", "bossmode"));
 		given(this.securityContext.getPrincipal()).willReturn(this.principal);
 		given(this.securityContext.isUserInRole("root")).willReturn(true);
@@ -204,9 +198,8 @@ class AutoConfiguredHealthEndpointGroupTests {
 
 	@Test
 	void showComponentsWhenShowComponentsIsWhenAuthorizedAndUseIsNotInRoleReturnsFalse() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, Show.WHEN_AUTHORIZED, Show.NEVER,
-				Arrays.asList("admin", "rot", "bossmode"));
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, Show.WHEN_AUTHORIZED, Show.NEVER, Arrays.asList("admin", "rot", "bossmode"));
 		given(this.securityContext.getPrincipal()).willReturn(this.principal);
 		given(this.securityContext.isUserInRole("root")).willReturn(true);
 		assertThat(group.showComponents(this.securityContext)).isFalse();
@@ -214,8 +207,8 @@ class AutoConfiguredHealthEndpointGroupTests {
 
 	@Test
 	void showComponentsWhenShowComponentsIsWhenAuthorizedAndUserHasRightAuthoritiesReturnsTrue() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, Show.WHEN_AUTHORIZED, Show.NEVER,
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, Show.WHEN_AUTHORIZED, Show.NEVER,
 				Arrays.asList("admin", "root", "bossmode"));
 		Authentication principal = mock(Authentication.class);
 		given(principal.getAuthorities())
@@ -226,9 +219,8 @@ class AutoConfiguredHealthEndpointGroupTests {
 
 	@Test
 	void showComponentsWhenShowComponentsIsWhenAuthorizedAndUserDoesNotHaveRightAuthoritiesReturnsFalse() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, Show.WHEN_AUTHORIZED, Show.NEVER,
-				Arrays.asList("admin", "rot", "bossmode"));
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, Show.WHEN_AUTHORIZED, Show.NEVER, Arrays.asList("admin", "rot", "bossmode"));
 		Authentication principal = mock(Authentication.class);
 		given(principal.getAuthorities())
 				.willAnswer((invocation) -> Collections.singleton(new SimpleGrantedAuthority("other")));
@@ -238,15 +230,15 @@ class AutoConfiguredHealthEndpointGroupTests {
 
 	@Test
 	void getStatusAggregatorReturnsStatusAggregator() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, null, Show.ALWAYS, Collections.emptySet());
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, null, Show.ALWAYS, Collections.emptySet());
 		assertThat(group.getStatusAggregator()).isSameAs(this.statusAggregator);
 	}
 
 	@Test
 	void getHttpCodeStatusMapperReturnsHttpCodeStatusMapper() {
-		AutoConfiguredHealthEndpointGroup group = new AutoConfiguredHealthEndpointGroup((name) -> true,
-				this.statusAggregator, this.httpCodeStatusMapper, null, Show.ALWAYS, Collections.emptySet());
+		DefaultHealthEndpointGroup group = new DefaultHealthEndpointGroup((name) -> true, this.statusAggregator,
+				this.httpCodeStatusMapper, null, Show.ALWAYS, Collections.emptySet());
 		assertThat(group.getHttpCodeStatusMapper()).isSameAs(this.httpCodeStatusMapper);
 	}
 

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

@@ -37,6 +37,7 @@ import org.springframework.boot.actuate.health.HealthComponent;
 import org.springframework.boot.actuate.health.HealthContributorRegistry;
 import org.springframework.boot.actuate.health.HealthEndpoint;
 import org.springframework.boot.actuate.health.HealthEndpointGroups;
+import org.springframework.boot.actuate.health.HealthEndpointGroupsRegistryCustomizer;
 import org.springframework.boot.actuate.health.HealthEndpointWebExtension;
 import org.springframework.boot.actuate.health.HealthIndicator;
 import org.springframework.boot.actuate.health.HttpCodeStatusMapper;
@@ -154,7 +155,6 @@ class HealthEndpointAutoConfigurationTests {
 	void runCreatesHealthEndpointGroups() {
 		this.contextRunner.withPropertyValues("management.endpoint.health.group.ready.include=*").run((context) -> {
 			HealthEndpointGroups groups = context.getBean(HealthEndpointGroups.class);
-			assertThat(groups).isInstanceOf(AutoConfiguredHealthEndpointGroups.class);
 			assertThat(groups.getNames()).containsOnly("ready");
 		});
 	}
@@ -301,6 +301,15 @@ class HealthEndpointAutoConfigurationTests {
 				.run((context) -> assertThat(context).doesNotHaveBean(ReactiveHealthIndicatorRegistry.class));
 	}
 
+	@Test
+	void runWhenHealthEndpointGroupsRegistryCustomizerAddsHealthEndpointGroup() {
+		this.contextRunner.withUserConfiguration(HealthEndpointGroupsRegistryCustomizerConfig.class).run((context) -> {
+			assertThat(context).hasSingleBean(HealthEndpointGroupsRegistryCustomizer.class);
+			HealthEndpointGroups groups = context.getBean(HealthEndpointGroups.class);
+			assertThat(groups.getNames()).contains("test");
+		});
+	}
+
 	@Configuration(proxyBeanMethods = false)
 	static class HealthIndicatorsConfiguration {
 
@@ -420,4 +429,14 @@ class HealthEndpointAutoConfigurationTests {
 
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	static class HealthEndpointGroupsRegistryCustomizerConfig {
+
+		@Bean
+		HealthEndpointGroupsRegistryCustomizer customHealthEndpointGroup() {
+			return (registry) -> registry.add("test", (configurer) -> configurer.include("ping"));
+		}
+
+	}
+
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -23,6 +23,7 @@ import org.springframework.boot.actuate.endpoint.SecurityContext;
  * by the {@link HealthEndpoint}.
  *
  * @author Phillip Webb
+ * @author Brian Clozel
  * @since 2.2.0
  */
 public interface HealthEndpointGroup {
@@ -62,4 +63,27 @@ public interface HealthEndpointGroup {
 	 */
 	HttpCodeStatusMapper getHttpCodeStatusMapper();
 
+	/**
+	 * Options for showing items in responses from the {@link HealthEndpointGroup} web
+	 * extensions.
+	 */
+	enum Show {
+
+		/**
+		 * Never show the item in the response.
+		 */
+		NEVER,
+
+		/**
+		 * Show the item in the response when accessed by an authorized user.
+		 */
+		WHEN_AUTHORIZED,
+
+		/**
+		 * Always show the item in the response.
+		 */
+		ALWAYS
+
+	}
+
 }

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

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2012-2020 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 org.springframework.boot.actuate.health;
+
+import org.springframework.boot.actuate.health.HealthEndpointGroup.Show;
+
+/**
+ * A configurer for customizing an {@link HealthEndpointGroup} being built.
+ *
+ * @author Brian Clozel
+ * @since 2.3.0
+ */
+public interface HealthEndpointGroupConfigurer {
+
+	/**
+	 * Configure the indicator endpoint ids to include in this group.
+	 * @param indicators the indicator endpoint ids
+	 * @return the configurer instance
+	 */
+	HealthEndpointGroupConfigurer include(String... indicators);
+
+	/**
+	 * Configure the indicator endpoint ids to exclude from this group.
+	 * @param indicators the indicator endpoint ids
+	 * @return the configurer instance
+	 */
+	HealthEndpointGroupConfigurer exclude(String... indicators);
+
+	/**
+	 * Configure the {@link StatusAggregator} to use for this group.
+	 * <p>
+	 * If none set, this will default to the globalmy configured {@link StatusAggregator}.
+	 * @param statusAggregator the status aggregator
+	 * @return the configurer instance
+	 */
+	HealthEndpointGroupConfigurer statusAggregator(StatusAggregator statusAggregator);
+
+	/**
+	 * Configure the {@link HttpCodeStatusMapper} to use for this group.
+	 * <p>
+	 * If none set, this will default to the globalmy configured
+	 * {@link HttpCodeStatusMapper}.
+	 * @param httpCodeStatusMapper the status code mapper
+	 * @return the configurer instance
+	 */
+	HealthEndpointGroupConfigurer httpCodeStatusMapper(HttpCodeStatusMapper httpCodeStatusMapper);
+
+	/**
+	 * Configure the {@link Show visbility option} for showing components of this group.
+	 * @param showComponents the components visibility
+	 * @return the configurer instance
+	 */
+	HealthEndpointGroupConfigurer showComponents(Show showComponents);
+
+	/**
+	 * Configure the {@link Show visbility option} for showing details of this group.
+	 * @param showDetails the details visibility
+	 * @return the configurer instance
+	 */
+	HealthEndpointGroupConfigurer showDetails(Show showDetails);
+
+	/**
+	 * Configure roles used to determine whether or not a user is authorized to be shown
+	 * details.
+	 * @param roles the roles
+	 * @return the configurer instance
+	 */
+	HealthEndpointGroupConfigurer roles(String... roles);
+
+}

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

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2012-2020 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 org.springframework.boot.actuate.health;
+
+import java.util.function.Consumer;
+
+/**
+ * Builder for an {@link HealthEndpointGroups} immutable instance.
+ *
+ * @author Brian Clozel
+ * @since 2.3.0
+ */
+public interface HealthEndpointGroupsRegistry extends HealthEndpointGroups {
+
+	/**
+	 * Add a new {@link HealthEndpointGroup}.
+	 * @param groupName the name of the group to add
+	 * @param builder the group to add
+	 * @return the builder instance
+	 */
+	HealthEndpointGroupsRegistry add(String groupName, Consumer<HealthEndpointGroupConfigurer> builder);
+
+	/**
+	 * Remove an existing {@link HealthEndpointGroup}.
+	 * @param groupName the name of the group to remove
+	 * @return the builder instance
+	 */
+	HealthEndpointGroupsRegistry remove(String groupName);
+
+	/**
+	 * Build an immutable {@link HealthEndpointGroups}.
+	 * @return the {@link HealthEndpointGroups}
+	 */
+	HealthEndpointGroups toGroups();
+
+}

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

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2012-2020 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 org.springframework.boot.actuate.health;
+
+/**
+ * Callback interface that can be used to customize a
+ * {@link HealthEndpointGroupsRegistry}.
+ *
+ * @author Brian Clozel
+ * @since 2.3.0
+ */
+@FunctionalInterface
+public interface HealthEndpointGroupsRegistryCustomizer {
+
+	/**
+	 * Callback to customize a {@link HealthEndpointGroupsRegistry} instance.
+	 * @param healthEndpointGroupsRegistry the registry to customize
+	 */
+	void customize(HealthEndpointGroupsRegistry healthEndpointGroupsRegistry);
+
+}