Merge pull request #17515 from htztomic

* pr/17515:
  Polish "Add support for configuring logging groups"
  Add support for configuring logging groups via endpoint

Closes gh-17515

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/asciidoc/endpoints/loggers.adoc

@@ -57,6 +57,21 @@ include::{snippets}loggers/single/response-fields.adoc[]
 
 
 
+[[loggers-group]]
+== Retrieving a Single Group
+
+To retrieve a single group, make a `GET` request to `/actuator/loggers/{group.name}`,
+as shown in the following curl-based example:
+
+include::{snippets}loggers/group/curl-request.adoc[]
+
+The preceding example retrieves information about the logger group named `test`. The
+resulting response is similar to the following:
+
+include::{snippets}loggers/group/http-response.adoc[]
+
+
+
 [[loggers-setting-level]]
 == Setting a Log Level
 
@@ -81,6 +96,30 @@ include::{snippets}loggers/set/request-fields.adoc[]
 
 
 
+[[loggers-setting-level]]
+== Setting a Log Level for a Group
+
+To set the level of a logger, make a `POST` request to
+`/actuator/loggers/{group.name}` with a JSON body that specifies the configured level
+for the logger group, as shown in the following curl-based example:
+
+include::{snippets}loggers/setGroup/curl-request.adoc[]
+
+The preceding example sets the `configuredLevel` of the `test` logger group to `DEBUG`.
+
+
+
+[[loggers-setting-level-request-structure]]
+=== Request Structure
+
+The request specifies the desired level of the logger group. The following table describes the
+structure of the request:
+
+[cols="3,1,3"]
+include::{snippets}loggers/set/request-fields.adoc[]
+
+
+
 [[loggers-clearing-level]]
 == Clearing a Log Level
 

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/logging/LoggersEndpointAutoConfiguration.java

@@ -16,6 +16,7 @@
 
 package org.springframework.boot.actuate.autoconfigure.logging;
 
+import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.actuate.autoconfigure.endpoint.condition.ConditionalOnAvailableEndpoint;
 import org.springframework.boot.actuate.logging.LoggersEndpoint;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
@@ -24,6 +25,7 @@ import org.springframework.boot.autoconfigure.condition.ConditionOutcome;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.SpringBootCondition;
+import org.springframework.boot.logging.LoggerGroups;
 import org.springframework.boot.logging.LoggingSystem;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ConditionContext;
@@ -45,8 +47,9 @@ public class LoggersEndpointAutoConfiguration {
 	@ConditionalOnBean(LoggingSystem.class)
 	@Conditional(OnEnabledLoggingSystemCondition.class)
 	@ConditionalOnMissingBean
-	public LoggersEndpoint loggersEndpoint(LoggingSystem loggingSystem) {
-		return new LoggersEndpoint(loggingSystem);
+	public LoggersEndpoint loggersEndpoint(LoggingSystem loggingSystem,
+			ObjectProvider<LoggerGroups> springBootLoggerGroups) {
+		return new LoggersEndpoint(loggingSystem, springBootLoggerGroups.getIfAvailable(LoggerGroups::new));
 	}
 
 	static class OnEnabledLoggingSystemCondition extends SpringBootCondition {

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/documentation/LoggersEndpointDocumentationTests.java

@@ -17,14 +17,18 @@
 package org.springframework.boot.actuate.autoconfigure.endpoint.web.documentation;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.EnumSet;
 import java.util.List;
+import java.util.Map;
 
 import org.junit.jupiter.api.Test;
 
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.actuate.logging.LoggersEndpoint;
 import org.springframework.boot.logging.LogLevel;
 import org.springframework.boot.logging.LoggerConfiguration;
+import org.springframework.boot.logging.LoggerGroups;
 import org.springframework.boot.logging.LoggingSystem;
 import org.springframework.boot.test.mock.mockito.MockBean;
 import org.springframework.context.annotation.Bean;
@@ -54,9 +58,21 @@ class LoggersEndpointDocumentationTests extends MockMvcEndpointDocumentationTest
 			fieldWithPath("configuredLevel").description("Configured level of the logger, if any.").optional(),
 			fieldWithPath("effectiveLevel").description("Effective level of the logger."));
 
+	private static final List<FieldDescriptor> groupLevelFields;
+
+	static {
+		groupLevelFields = Arrays.asList(
+				fieldWithPath("configuredLevel").description("Configured level of the logger group")
+						.type(LogLevel.class).optional(),
+				fieldWithPath("members").description("Loggers that are part of this group").optional());
+	}
+
 	@MockBean
 	private LoggingSystem loggingSystem;
 
+	@Autowired
+	private LoggerGroups loggerGroups;
+
 	@Test
 	void allLoggers() throws Exception {
 		given(this.loggingSystem.getSupportedLogLevels()).willReturn(EnumSet.allOf(LogLevel.class));
@@ -66,8 +82,10 @@ class LoggersEndpointDocumentationTests extends MockMvcEndpointDocumentationTest
 		this.mockMvc.perform(get("/actuator/loggers")).andExpect(status().isOk())
 				.andDo(MockMvcRestDocumentation.document("loggers/all",
 						responseFields(fieldWithPath("levels").description("Levels support by the logging system."),
-								fieldWithPath("loggers").description("Loggers keyed by name."))
-										.andWithPrefix("loggers.*.", levelFields)));
+								fieldWithPath("loggers").description("Loggers keyed by name."),
+								fieldWithPath("groups").description("Logger groups keyed by name"))
+										.andWithPrefix("loggers.*.", levelFields)
+										.andWithPrefix("groups.*.", groupLevelFields)));
 	}
 
 	@Test
@@ -78,6 +96,12 @@ class LoggersEndpointDocumentationTests extends MockMvcEndpointDocumentationTest
 				.andDo(MockMvcRestDocumentation.document("loggers/single", responseFields(levelFields)));
 	}
 
+	@Test
+	void loggerGroups() throws Exception {
+		this.mockMvc.perform(get("/actuator/loggers/test")).andExpect(status().isOk())
+				.andDo(MockMvcRestDocumentation.document("loggers/group", responseFields(groupLevelFields)));
+	}
+
 	@Test
 	void setLogLevel() throws Exception {
 		this.mockMvc
@@ -89,6 +113,26 @@ class LoggersEndpointDocumentationTests extends MockMvcEndpointDocumentationTest
 		verify(this.loggingSystem).setLogLevel("com.example", LogLevel.DEBUG);
 	}
 
+	@Test
+	void setLogLevelOfLoggerGroup() throws Exception {
+		this.mockMvc
+				.perform(post("/actuator/loggers/test")
+						.content("{\"configuredLevel\":\"debug\"}").contentType(MediaType.APPLICATION_JSON))
+				.andExpect(status().isNoContent()).andDo(
+						MockMvcRestDocumentation.document("loggers/setGroup",
+								requestFields(fieldWithPath("configuredLevel").description(
+										"Level for the logger group. May be omitted to clear the level of the loggers.")
+										.optional())));
+		verify(this.loggingSystem).setLogLevel("test.member1", LogLevel.DEBUG);
+		verify(this.loggingSystem).setLogLevel("test.member2", LogLevel.DEBUG);
+		resetLogger();
+	}
+
+	private void resetLogger() {
+		this.loggerGroups.get("test").configureLogLevel(null, (a, b) -> {
+		});
+	}
+
 	@Test
 	void clearLogLevel() throws Exception {
 		this.mockMvc
@@ -102,8 +146,13 @@ class LoggersEndpointDocumentationTests extends MockMvcEndpointDocumentationTest
 	static class TestConfiguration {
 
 		@Bean
-		LoggersEndpoint endpoint(LoggingSystem loggingSystem) {
-			return new LoggersEndpoint(loggingSystem);
+		LoggersEndpoint endpoint(LoggingSystem loggingSystem, LoggerGroups groups) {
+			groups.putAll(getLoggerGroups());
+			return new LoggersEndpoint(loggingSystem, groups);
+		}
+
+		private Map<String, List<String>> getLoggerGroups() {
+			return Collections.singletonMap("test", Arrays.asList("test.member1", "test.member2"));
 		}
 
 	}

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/logging/LoggersEndpoint.java

@@ -19,6 +19,7 @@ package org.springframework.boot.actuate.logging;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.LinkedHashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.NavigableSet;
 import java.util.Set;
@@ -30,6 +31,8 @@ import org.springframework.boot.actuate.endpoint.annotation.Selector;
 import org.springframework.boot.actuate.endpoint.annotation.WriteOperation;
 import org.springframework.boot.logging.LogLevel;
 import org.springframework.boot.logging.LoggerConfiguration;
+import org.springframework.boot.logging.LoggerGroup;
+import org.springframework.boot.logging.LoggerGroups;
 import org.springframework.boot.logging.LoggingSystem;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
@@ -39,6 +42,7 @@ import org.springframework.util.Assert;
  *
  * @author Ben Hale
  * @author Phillip Webb
+ * @author HaiTao Zhang
  * @since 2.0.0
  */
 @Endpoint(id = "loggers")
@@ -46,13 +50,18 @@ public class LoggersEndpoint {
 
 	private final LoggingSystem loggingSystem;
 
+	private final LoggerGroups loggerGroups;
+
 	/**
 	 * Create a new {@link LoggersEndpoint} instance.
 	 * @param loggingSystem the logging system to expose
+	 * @param loggerGroups the logger group to expose
 	 */
-	public LoggersEndpoint(LoggingSystem loggingSystem) {
+	public LoggersEndpoint(LoggingSystem loggingSystem, LoggerGroups loggerGroups) {
 		Assert.notNull(loggingSystem, "LoggingSystem must not be null");
+		Assert.notNull(loggerGroups, "LoggerGroups must not be null");
 		this.loggingSystem = loggingSystem;
+		this.loggerGroups = loggerGroups;
 	}
 
 	@ReadOperation
@@ -64,19 +73,36 @@ public class LoggersEndpoint {
 		Map<String, Object> result = new LinkedHashMap<>();
 		result.put("levels", getLevels());
 		result.put("loggers", getLoggers(configurations));
+		result.put("groups", getGroups());
 		return result;
 	}
 
+	private Map<String, LoggerLevels> getGroups() {
+		Map<String, LoggerLevels> groups = new LinkedHashMap<>();
+		this.loggerGroups.forEach((group) -> groups.put(group.getName(),
+				new GroupLoggerLevels(group.getConfiguredLevel(), group.getMembers())));
+		return groups;
+	}
+
 	@ReadOperation
 	public LoggerLevels loggerLevels(@Selector String name) {
 		Assert.notNull(name, "Name must not be null");
+		LoggerGroup group = this.loggerGroups.get(name);
+		if (group != null) {
+			return new GroupLoggerLevels(group.getConfiguredLevel(), group.getMembers());
+		}
 		LoggerConfiguration configuration = this.loggingSystem.getLoggerConfiguration(name);
-		return (configuration != null) ? new LoggerLevels(configuration) : null;
+		return (configuration != null) ? new SingleLoggerLevels(configuration) : null;
 	}
 
 	@WriteOperation
 	public void configureLogLevel(@Selector String name, @Nullable LogLevel configuredLevel) {
 		Assert.notNull(name, "Name must not be empty");
+		LoggerGroup group = this.loggerGroups.get(name);
+		if (group != null && group.hasMembers()) {
+			group.configureLogLevel(configuredLevel, this.loggingSystem::setLogLevel);
+			return;
+		}
 		this.loggingSystem.setLogLevel(name, configuredLevel);
 	}
 
@@ -88,7 +114,7 @@ public class LoggersEndpoint {
 	private Map<String, LoggerLevels> getLoggers(Collection<LoggerConfiguration> configurations) {
 		Map<String, LoggerLevels> loggers = new LinkedHashMap<>(configurations.size());
 		for (LoggerConfiguration configuration : configurations) {
-			loggers.put(configuration.getName(), new LoggerLevels(configuration));
+			loggers.put(configuration.getName(), new SingleLoggerLevels(configuration));
 		}
 		return loggers;
 	}
@@ -100,14 +126,11 @@ public class LoggersEndpoint {
 
 		private String configuredLevel;
 
-		private String effectiveLevel;
-
-		public LoggerLevels(LoggerConfiguration configuration) {
-			this.configuredLevel = getName(configuration.getConfiguredLevel());
-			this.effectiveLevel = getName(configuration.getEffectiveLevel());
+		public LoggerLevels(LogLevel configuredLevel) {
+			this.configuredLevel = getName(configuredLevel);
 		}
 
-		private String getName(LogLevel level) {
+		protected final String getName(LogLevel level) {
 			return (level != null) ? level.name() : null;
 		}
 
@@ -115,6 +138,32 @@ public class LoggersEndpoint {
 			return this.configuredLevel;
 		}
 
+	}
+
+	public static class GroupLoggerLevels extends LoggerLevels {
+
+		private List<String> members;
+
+		public GroupLoggerLevels(LogLevel configuredLevel, List<String> members) {
+			super(configuredLevel);
+			this.members = members;
+		}
+
+		public List<String> getMembers() {
+			return this.members;
+		}
+
+	}
+
+	public static class SingleLoggerLevels extends LoggerLevels {
+
+		private String effectiveLevel;
+
+		public SingleLoggerLevels(LoggerConfiguration configuration) {
+			super(configuration.getConfiguredLevel());
+			this.effectiveLevel = getName(configuration.getEffectiveLevel());
+		}
+
 		public String getEffectiveLevel() {
 			return this.effectiveLevel;
 		}

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/logging/LoggersEndpointTests.java

@@ -18,14 +18,19 @@ package org.springframework.boot.actuate.logging;
 
 import java.util.Collections;
 import java.util.EnumSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
+import org.springframework.boot.actuate.logging.LoggersEndpoint.GroupLoggerLevels;
 import org.springframework.boot.actuate.logging.LoggersEndpoint.LoggerLevels;
+import org.springframework.boot.actuate.logging.LoggersEndpoint.SingleLoggerLevels;
 import org.springframework.boot.logging.LogLevel;
 import org.springframework.boot.logging.LoggerConfiguration;
+import org.springframework.boot.logging.LoggerGroups;
 import org.springframework.boot.logging.LoggingSystem;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -38,46 +43,102 @@ import static org.mockito.Mockito.verify;
  *
  * @author Ben Hale
  * @author Andy Wilkinson
+ * @author HaiTao Zhang
+ * @author Madhura Bhave
  */
 class LoggersEndpointTests {
 
 	private final LoggingSystem loggingSystem = mock(LoggingSystem.class);
 
+	private LoggerGroups loggerGroups;
+
+	@BeforeEach
+	void setup() {
+		Map<String, List<String>> groups = Collections.singletonMap("test", Collections.singletonList("test.member"));
+		this.loggerGroups = new LoggerGroups(groups);
+		this.loggerGroups.get("test").configureLogLevel(LogLevel.DEBUG, (a, b) -> {
+		});
+	}
+
 	@Test
 	@SuppressWarnings("unchecked")
-	void loggersShouldReturnLoggerConfigurations() {
+	void loggersShouldReturnLoggerConfigurationsWithNoLoggerGroups() {
 		given(this.loggingSystem.getLoggerConfigurations())
 				.willReturn(Collections.singletonList(new LoggerConfiguration("ROOT", null, LogLevel.DEBUG)));
 		given(this.loggingSystem.getSupportedLogLevels()).willReturn(EnumSet.allOf(LogLevel.class));
-		Map<String, Object> result = new LoggersEndpoint(this.loggingSystem).loggers();
+		Map<String, Object> result = new LoggersEndpoint(this.loggingSystem, new LoggerGroups()).loggers();
 		Map<String, LoggerLevels> loggers = (Map<String, LoggerLevels>) result.get("loggers");
 		Set<LogLevel> levels = (Set<LogLevel>) result.get("levels");
-		LoggerLevels rootLevels = loggers.get("ROOT");
+		SingleLoggerLevels rootLevels = (SingleLoggerLevels) loggers.get("ROOT");
 		assertThat(rootLevels.getConfiguredLevel()).isNull();
 		assertThat(rootLevels.getEffectiveLevel()).isEqualTo("DEBUG");
 		assertThat(levels).containsExactly(LogLevel.OFF, LogLevel.FATAL, LogLevel.ERROR, LogLevel.WARN, LogLevel.INFO,
 				LogLevel.DEBUG, LogLevel.TRACE);
+		Map<String, LoggerGroups> groups = (Map<String, LoggerGroups>) result.get("groups");
+		assertThat(groups).isEmpty();
+	}
+
+	@Test
+	@SuppressWarnings("unchecked")
+	void loggersShouldReturnLoggerConfigurationsWithLoggerGroups() {
+		given(this.loggingSystem.getLoggerConfigurations())
+				.willReturn(Collections.singletonList(new LoggerConfiguration("ROOT", null, LogLevel.DEBUG)));
+		given(this.loggingSystem.getSupportedLogLevels()).willReturn(EnumSet.allOf(LogLevel.class));
+		Map<String, Object> result = new LoggersEndpoint(this.loggingSystem, this.loggerGroups).loggers();
+		Map<String, GroupLoggerLevels> loggerGroups = (Map<String, GroupLoggerLevels>) result.get("groups");
+		GroupLoggerLevels groupLevel = loggerGroups.get("test");
+		Map<String, LoggerLevels> loggers = (Map<String, LoggerLevels>) result.get("loggers");
+		Set<LogLevel> levels = (Set<LogLevel>) result.get("levels");
+		SingleLoggerLevels rootLevels = (SingleLoggerLevels) loggers.get("ROOT");
+		assertThat(rootLevels.getConfiguredLevel()).isNull();
+		assertThat(rootLevels.getEffectiveLevel()).isEqualTo("DEBUG");
+		assertThat(levels).containsExactly(LogLevel.OFF, LogLevel.FATAL, LogLevel.ERROR, LogLevel.WARN, LogLevel.INFO,
+				LogLevel.DEBUG, LogLevel.TRACE);
+		assertThat(loggerGroups).isNotNull();
+		assertThat(groupLevel.getConfiguredLevel()).isEqualTo("DEBUG");
+		assertThat(groupLevel.getMembers()).containsExactly("test.member");
 	}
 
 	@Test
 	void loggerLevelsWhenNameSpecifiedShouldReturnLevels() {
 		given(this.loggingSystem.getLoggerConfiguration("ROOT"))
 				.willReturn(new LoggerConfiguration("ROOT", null, LogLevel.DEBUG));
-		LoggerLevels levels = new LoggersEndpoint(this.loggingSystem).loggerLevels("ROOT");
+		SingleLoggerLevels levels = (SingleLoggerLevels) new LoggersEndpoint(this.loggingSystem, this.loggerGroups)
+				.loggerLevels("ROOT");
 		assertThat(levels.getConfiguredLevel()).isNull();
 		assertThat(levels.getEffectiveLevel()).isEqualTo("DEBUG");
 	}
 
+	@Test
+	void groupNameSpecifiedShouldReturnConfiguredLevelAndMembers() {
+		GroupLoggerLevels levels = (GroupLoggerLevels) new LoggersEndpoint(this.loggingSystem, this.loggerGroups)
+				.loggerLevels("test");
+		assertThat(levels.getConfiguredLevel()).isEqualTo("DEBUG");
+		assertThat(levels.getMembers()).isEqualTo(Collections.singletonList("test.member"));
+	}
+
 	@Test
 	void configureLogLevelShouldSetLevelOnLoggingSystem() {
-		new LoggersEndpoint(this.loggingSystem).configureLogLevel("ROOT", LogLevel.DEBUG);
+		new LoggersEndpoint(this.loggingSystem, this.loggerGroups).configureLogLevel("ROOT", LogLevel.DEBUG);
 		verify(this.loggingSystem).setLogLevel("ROOT", LogLevel.DEBUG);
 	}
 
 	@Test
 	void configureLogLevelWithNullSetsLevelOnLoggingSystemToNull() {
-		new LoggersEndpoint(this.loggingSystem).configureLogLevel("ROOT", null);
+		new LoggersEndpoint(this.loggingSystem, this.loggerGroups).configureLogLevel("ROOT", null);
 		verify(this.loggingSystem).setLogLevel("ROOT", null);
 	}
 
+	@Test
+	void configureLogLevelInLoggerGroupShouldSetLevelOnLoggingSystem() {
+		new LoggersEndpoint(this.loggingSystem, this.loggerGroups).configureLogLevel("test", LogLevel.DEBUG);
+		verify(this.loggingSystem).setLogLevel("test.member", LogLevel.DEBUG);
+	}
+
+	@Test
+	void configureLogLevelWithNullInLoggerGroupShouldSetLevelOnLoggingSystem() {
+		new LoggersEndpoint(this.loggingSystem, this.loggerGroups).configureLogLevel("test", null);
+		verify(this.loggingSystem).setLogLevel("test.member", null);
+	}
+
 }

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/logging/LoggersEndpointWebIntegrationTests.java

@@ -19,16 +19,22 @@ package org.springframework.boot.actuate.logging;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.EnumSet;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
 
 import net.minidev.json.JSONArray;
+import org.hamcrest.collection.IsIterableContainingInAnyOrder;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.mockito.Mockito;
 
+import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.actuate.endpoint.http.ActuatorMediaType;
 import org.springframework.boot.actuate.endpoint.web.test.WebEndpointTest;
 import org.springframework.boot.logging.LogLevel;
 import org.springframework.boot.logging.LoggerConfiguration;
+import org.springframework.boot.logging.LoggerGroups;
 import org.springframework.boot.logging.LoggingSystem;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
@@ -50,6 +56,8 @@ import static org.mockito.Mockito.verifyZeroInteractions;
  * @author Eddú Meléndez
  * @author Stephane Nicoll
  * @author Andy Wilkinson
+ * @author HaiTao Zhang
+ * @author Madhura Bhave
  */
 class LoggersEndpointWebIntegrationTests {
 
@@ -57,29 +65,35 @@ class LoggersEndpointWebIntegrationTests {
 
 	private LoggingSystem loggingSystem;
 
+	private LoggerGroups loggerGroups;
+
 	@BeforeEach
 	@AfterEach
 	void resetMocks(ConfigurableApplicationContext context, WebTestClient client) {
 		this.client = client;
 		this.loggingSystem = context.getBean(LoggingSystem.class);
+		this.loggerGroups = context.getBean(LoggerGroups.class);
 		Mockito.reset(this.loggingSystem);
 		given(this.loggingSystem.getSupportedLogLevels()).willReturn(EnumSet.allOf(LogLevel.class));
 	}
 
 	@WebEndpointTest
-	void getLoggerShouldReturnAllLoggerConfigurations() {
+	void getLoggerShouldReturnAllLoggerConfigurationsWithLoggerGroups() {
+		setLogLevelToDebug("test");
 		given(this.loggingSystem.getLoggerConfigurations())
 				.willReturn(Collections.singletonList(new LoggerConfiguration("ROOT", null, LogLevel.DEBUG)));
 		this.client.get().uri("/actuator/loggers").exchange().expectStatus().isOk().expectBody().jsonPath("$.length()")
-				.isEqualTo(2).jsonPath("levels")
+				.isEqualTo(3).jsonPath("levels")
 				.isEqualTo(jsonArrayOf("OFF", "FATAL", "ERROR", "WARN", "INFO", "DEBUG", "TRACE"))
 				.jsonPath("loggers.length()").isEqualTo(1).jsonPath("loggers.ROOT.length()").isEqualTo(2)
 				.jsonPath("loggers.ROOT.configuredLevel").isEqualTo(null).jsonPath("loggers.ROOT.effectiveLevel")
+				.isEqualTo("DEBUG").jsonPath("groups.length()").isEqualTo(2).jsonPath("groups.test.configuredLevel")
 				.isEqualTo("DEBUG");
 	}
 
 	@WebEndpointTest
 	void getLoggerShouldReturnLogLevels() {
+		setLogLevelToDebug("test");
 		given(this.loggingSystem.getLoggerConfiguration("ROOT"))
 				.willReturn(new LoggerConfiguration("ROOT", null, LogLevel.DEBUG));
 		this.client.get().uri("/actuator/loggers/ROOT").exchange().expectStatus().isOk().expectBody()
@@ -88,10 +102,19 @@ class LoggersEndpointWebIntegrationTests {
 	}
 
 	@WebEndpointTest
-	void getLoggersWhenLoggerNotFoundShouldReturnNotFound() {
+	void getLoggersWhenLoggerAndLoggerGroupNotFoundShouldReturnNotFound() {
 		this.client.get().uri("/actuator/loggers/com.does.not.exist").exchange().expectStatus().isNotFound();
 	}
 
+	@WebEndpointTest
+	void getLoggerGroupShouldReturnConfiguredLogLevelAndMembers() {
+		setLogLevelToDebug("test");
+		this.client.get().uri("actuator/loggers/test").exchange().expectStatus().isOk().expectBody()
+				.jsonPath("$.length()").isEqualTo(2).jsonPath("members")
+				.value(IsIterableContainingInAnyOrder.containsInAnyOrder("test.member1", "test.member2"))
+				.jsonPath("configuredLevel").isEqualTo("DEBUG");
+	}
+
 	@WebEndpointTest
 	void setLoggerUsingApplicationJsonShouldSetLogLevel() {
 		this.client.post().uri("/actuator/loggers/ROOT").contentType(MediaType.APPLICATION_JSON)
@@ -108,7 +131,24 @@ class LoggersEndpointWebIntegrationTests {
 	}
 
 	@WebEndpointTest
-	void setLoggerWithWrongLogLevelResultInBadRequestResponse() {
+	void setLoggerGroupUsingActuatorV2JsonShouldSetLogLevel() {
+		this.client.post().uri("/actuator/loggers/test")
+				.contentType(MediaType.parseMediaType(ActuatorMediaType.V2_JSON))
+				.body(Collections.singletonMap("configuredLevel", "debug")).exchange().expectStatus().isNoContent();
+		verify(this.loggingSystem).setLogLevel("test.member1", LogLevel.DEBUG);
+		verify(this.loggingSystem).setLogLevel("test.member2", LogLevel.DEBUG);
+	}
+
+	@WebEndpointTest
+	void setLoggerGroupUsingApplicationJsonShouldSetLogLevel() {
+		this.client.post().uri("/actuator/loggers/test").contentType(MediaType.APPLICATION_JSON)
+				.body(Collections.singletonMap("configuredLevel", "debug")).exchange().expectStatus().isNoContent();
+		verify(this.loggingSystem).setLogLevel("test.member1", LogLevel.DEBUG);
+		verify(this.loggingSystem).setLogLevel("test.member2", LogLevel.DEBUG);
+	}
+
+	@WebEndpointTest
+	void setLoggerOrLoggerGroupWithWrongLogLevelResultInBadRequestResponse() {
 		this.client.post().uri("/actuator/loggers/ROOT").contentType(MediaType.APPLICATION_JSON)
 				.body(Collections.singletonMap("configuredLevel", "other")).exchange().expectStatus().isBadRequest();
 		verifyZeroInteractions(this.loggingSystem);
@@ -130,6 +170,24 @@ class LoggersEndpointWebIntegrationTests {
 		verify(this.loggingSystem).setLogLevel("ROOT", null);
 	}
 
+	@WebEndpointTest
+	void setLoggerGroupWithNullLogLevel() {
+		this.client.post().uri("/actuator/loggers/test")
+				.contentType(MediaType.parseMediaType(ActuatorMediaType.V2_JSON))
+				.body(Collections.singletonMap("configuredLevel", null)).exchange().expectStatus().isNoContent();
+		verify(this.loggingSystem).setLogLevel("test.member1", null);
+		verify(this.loggingSystem).setLogLevel("test.member2", null);
+	}
+
+	@WebEndpointTest
+	void setLoggerGroupWithNoLogLevel() {
+		this.client.post().uri("/actuator/loggers/test")
+				.contentType(MediaType.parseMediaType(ActuatorMediaType.V2_JSON)).body(Collections.emptyMap())
+				.exchange().expectStatus().isNoContent();
+		verify(this.loggingSystem).setLogLevel("test.member1", null);
+		verify(this.loggingSystem).setLogLevel("test.member2", null);
+	}
+
 	@WebEndpointTest
 	void logLevelForLoggerWithNameThatCouldBeMistakenForAPathExtension() {
 		given(this.loggingSystem.getLoggerConfiguration("com.png"))
@@ -139,6 +197,19 @@ class LoggersEndpointWebIntegrationTests {
 				.jsonPath("effectiveLevel").isEqualTo("DEBUG");
 	}
 
+	@WebEndpointTest
+	void logLevelForLoggerGroupWithNameThatCouldBeMistakenForAPathExtension() {
+		setLogLevelToDebug("group.png");
+		this.client.get().uri("/actuator/loggers/group.png").exchange().expectStatus().isOk().expectBody()
+				.jsonPath("$.length()").isEqualTo(2).jsonPath("configuredLevel").isEqualTo("DEBUG").jsonPath("members")
+				.value(IsIterableContainingInAnyOrder.containsInAnyOrder("png.member1", "png.member2"));
+	}
+
+	private void setLogLevelToDebug(String name) {
+		this.loggerGroups.get(name).configureLogLevel(LogLevel.DEBUG, (a, b) -> {
+		});
+	}
+
 	private JSONArray jsonArrayOf(Object... entries) {
 		JSONArray array = new JSONArray();
 		array.addAll(Arrays.asList(entries));
@@ -154,8 +225,21 @@ class LoggersEndpointWebIntegrationTests {
 		}
 
 		@Bean
-		LoggersEndpoint endpoint(LoggingSystem loggingSystem) {
-			return new LoggersEndpoint(loggingSystem);
+		LoggerGroups loggingGroups() {
+			return getLoggerGroups();
+		}
+
+		private LoggerGroups getLoggerGroups() {
+			Map<String, List<String>> groups = new LinkedHashMap<>();
+			groups.put("test", Arrays.asList("test.member1", "test.member2"));
+			groups.put("group.png", Arrays.asList("png.member1", "png.member2"));
+			return new LoggerGroups(groups);
+		}
+
+		@Bean
+		LoggersEndpoint endpoint(LoggingSystem loggingSystem,
+				ObjectProvider<LoggerGroups> loggingGroupsObjectProvider) {
+			return new LoggersEndpoint(loggingSystem, loggingGroupsObjectProvider.getIfAvailable());
 		}
 
 	}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/LoggerGroup.java

+/*
+ * Copyright 2012-2019 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.logging;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.function.BiConsumer;
+
+/**
+ * A single logger group.
+ *
+ * @author Madhura Bhave
+ * @author Phillip Webb
+ * @since 2.2.0
+ */
+public final class LoggerGroup {
+
+	private final String name;
+
+	private final List<String> members;
+
+	private LogLevel configuredLevel;
+
+	LoggerGroup(String name, List<String> members) {
+		this.name = name;
+		this.members = Collections.unmodifiableList(new ArrayList<>(members));
+	}
+
+	public String getName() {
+		return this.name;
+	}
+
+	public List<String> getMembers() {
+		return this.members;
+	}
+
+	public boolean hasMembers() {
+		return !this.members.isEmpty();
+	}
+
+	public LogLevel getConfiguredLevel() {
+		return this.configuredLevel;
+	}
+
+	public void configureLogLevel(LogLevel level, BiConsumer<String, LogLevel> configurer) {
+		this.configuredLevel = level;
+		this.members.forEach((name) -> configurer.accept(name, level));
+	}
+
+}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/LoggerGroups.java

+/*
+ * Copyright 2012-2019 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.logging;
+
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Logger groups configured via the Spring Environment.
+ *
+ * @author HaiTao Zhang
+ * @author Phillip Webb
+ * @since 2.2.0 #see {@link LoggerGroup}
+ */
+public final class LoggerGroups implements Iterable<LoggerGroup> {
+
+	private final Map<String, LoggerGroup> groups = new ConcurrentHashMap<>();
+
+	public LoggerGroups() {
+	}
+
+	public LoggerGroups(Map<String, List<String>> namesAndMembers) {
+		putAll(namesAndMembers);
+	}
+
+	public void putAll(Map<String, List<String>> namesAndMembers) {
+		namesAndMembers.forEach(this::put);
+	}
+
+	private void put(String name, List<String> members) {
+		put(new LoggerGroup(name, members));
+	}
+
+	private void put(LoggerGroup loggerGroup) {
+		this.groups.put(loggerGroup.getName(), loggerGroup);
+	}
+
+	public LoggerGroup get(String name) {
+		return this.groups.get(name);
+	}
+
+	@Override
+	public Iterator<LoggerGroup> iterator() {
+		return this.groups.values().iterator();
+	}
+
+}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/logging/LoggingApplicationListenerTests.java

@@ -50,6 +50,7 @@ import org.springframework.boot.logging.AbstractLoggingSystem;
 import org.springframework.boot.logging.LogFile;
 import org.springframework.boot.logging.LogLevel;
 import org.springframework.boot.logging.LoggerConfiguration;
+import org.springframework.boot.logging.LoggerGroups;
 import org.springframework.boot.logging.LoggingInitializationContext;
 import org.springframework.boot.logging.LoggingSystem;
 import org.springframework.boot.logging.LoggingSystemProperties;
@@ -284,6 +285,8 @@ class LoggingApplicationListenerTests {
 		this.loggerContext.getLogger("org.hibernate.SQL").debug("testdebugsqlgroup");
 		assertThat(this.output).contains("testdebugwebgroup");
 		assertThat(this.output).contains("testdebugsqlgroup");
+		LoggerGroups loggerGroups = (LoggerGroups) ReflectionTestUtils.getField(this.initializer, "loggerGroups");
+		assertThat(loggerGroups.get("web").getConfiguredLevel()).isEqualTo(LogLevel.DEBUG);
 	}
 
 	@Test

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/logging/LoggerGroupsTests.java

+/*
+ * Copyright 2012-2019 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.logging;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Tests for {@link LoggerGroups}
+ *
+ * @author HaiTao Zhang
+ * @author Madhura Bhave
+ */
+class LoggerGroupsTests {
+
+	private LoggingSystem loggingSystem = mock(LoggingSystem.class);
+
+	@Test
+	void putAllShouldAddLoggerGroups() {
+		Map<String, List<String>> groups = Collections.singletonMap("test",
+				Arrays.asList("test.member", "test.member2"));
+		LoggerGroups loggerGroups = new LoggerGroups();
+		loggerGroups.putAll(groups);
+		LoggerGroup group = loggerGroups.get("test");
+		assertThat(group.getMembers()).containsExactly("test.member", "test.member2");
+	}
+
+	@Test
+	void iteratorShouldReturnLoggerGroups() {
+		LoggerGroups groups = createLoggerGroups();
+		assertThat(groups).hasSize(3);
+		assertThat(groups).extracting("name").containsExactlyInAnyOrder("test0", "test1", "test2");
+	}
+
+	private LoggerGroups createLoggerGroups() {
+		Map<String, List<String>> groups = new LinkedHashMap<>();
+		groups.put("test0", Arrays.asList("test0.member", "test0.member2"));
+		groups.put("test1", Arrays.asList("test1.member", "test1.member2"));
+		groups.put("test2", Arrays.asList("test2.member", "test2.member2"));
+		return new LoggerGroups(groups);
+	}
+
+}