Rationalize structured logging service classes

Rename `ElasticCommonSchemaService` & `GraylogExtendedLogFormatService`
and change a few of the property names. The `Service` suffix was
originally chosen because ECS uses the term, but `Properties` is more
common in the Spring Boot codebase and works better for Graylog.

Closes gh-42578

Author: philwebb

spring-boot-project/spring-boot-docs/src/docs/antora/modules/reference/pages/features/logging.adoc

@@ -524,19 +524,19 @@ A log line looks like this:
 This format also adds every key value pair contained in the MDC to the JSON object.
 You can also use the https://www.slf4j.org/manual.html#fluent[SLF4J fluent logging API] to add key value pairs to the logged JSON object with the https://www.slf4j.org/apidocs/org/slf4j/spi/LoggingEventBuilder.html#addKeyValue(java.lang.String,java.lang.Object)[addKeyValue] method.
 
-The `service` values can be customized using `logging.structured.gelf.service` properties:
+Several fields can be customized using `logging.structured.gelf` properties:
 
 [configprops,yaml]
 ----
 logging:
   structured:
     gelf:
+      host: MyService
       service:
-        name: MyService
         version: 1.0
 ----
 
-NOTE: configprop:logging.structured.gelf.service.name[] will default to configprop:spring.application.name[] if not specified.
+NOTE: configprop:logging.structured.gelf.host[] will default to configprop:spring.application.name[] if not specified.
 
 NOTE: configprop:logging.structured.gelf.service.version[] will default to configprop:spring.application.version[] if not specified.
 

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/log4j2/ElasticCommonSchemaStructuredLogFormatter.java

@@ -26,7 +26,7 @@
 
 import org.springframework.boot.json.JsonWriter;
 import org.springframework.boot.logging.structured.CommonStructuredLogFormat;
-import org.springframework.boot.logging.structured.ElasticCommonSchemaService;
+import org.springframework.boot.logging.structured.ElasticCommonSchemaProperties;
 import org.springframework.boot.logging.structured.JsonWriterStructuredLogFormatter;
 import org.springframework.boot.logging.structured.StructuredLogFormatter;
 import org.springframework.core.env.Environment;
@@ -51,7 +51,7 @@ private static void jsonMembers(Environment environment, JsonWriter.Members<LogE
 		members.add("process.pid", environment.getProperty("spring.application.pid", Long.class))
 			.when(Objects::nonNull);
 		members.add("process.thread.name", LogEvent::getThreadName);
-		ElasticCommonSchemaService.get(environment).jsonMembers(members);
+		ElasticCommonSchemaProperties.get(environment).jsonMembers(members);
 		members.add("log.logger", LogEvent::getLoggerName);
 		members.add("message", LogEvent::getMessage).as(StructuredMessage::get);
 		members.from(LogEvent::getContextData)

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/log4j2/GraylogExtendedLogFormatStructuredLogFormatter.java

@@ -35,7 +35,7 @@
 import org.springframework.boot.json.JsonWriter.Members;
 import org.springframework.boot.json.WritableJson;
 import org.springframework.boot.logging.structured.CommonStructuredLogFormat;
-import org.springframework.boot.logging.structured.GraylogExtendedLogFormatService;
+import org.springframework.boot.logging.structured.GraylogExtendedLogFormatProperties;
 import org.springframework.boot.logging.structured.JsonWriterStructuredLogFormatter;
 import org.springframework.boot.logging.structured.StructuredLogFormatter;
 import org.springframework.core.env.Environment;
@@ -83,7 +83,7 @@ private static void jsonMembers(Environment environment, JsonWriter.Members<LogE
 		members.add("_process_pid", environment.getProperty("spring.application.pid", Long.class))
 			.when(Objects::nonNull);
 		members.add("_process_thread_name", LogEvent::getThreadName);
-		GraylogExtendedLogFormatService.get(environment).jsonMembers(members);
+		GraylogExtendedLogFormatProperties.get(environment).jsonMembers(members);
 		members.add("_log_logger", LogEvent::getLoggerName);
 		members.from(LogEvent::getContextData)
 			.whenNot(ReadOnlyStringMap::isEmpty)

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

@@ -26,7 +26,7 @@
 import org.springframework.boot.json.JsonWriter;
 import org.springframework.boot.json.JsonWriter.PairExtractor;
 import org.springframework.boot.logging.structured.CommonStructuredLogFormat;
-import org.springframework.boot.logging.structured.ElasticCommonSchemaService;
+import org.springframework.boot.logging.structured.ElasticCommonSchemaProperties;
 import org.springframework.boot.logging.structured.JsonWriterStructuredLogFormatter;
 import org.springframework.boot.logging.structured.StructuredLogFormatter;
 import org.springframework.core.env.Environment;
@@ -55,7 +55,7 @@ private static void jsonMembers(Environment environment, ThrowableProxyConverter
 		members.add("process.pid", environment.getProperty("spring.application.pid", Long.class))
 			.when(Objects::nonNull);
 		members.add("process.thread.name", ILoggingEvent::getThreadName);
-		ElasticCommonSchemaService.get(environment).jsonMembers(members);
+		ElasticCommonSchemaProperties.get(environment).jsonMembers(members);
 		members.add("log.logger", ILoggingEvent::getLoggerName);
 		members.add("message", ILoggingEvent::getFormattedMessage);
 		members.addMapEntries(ILoggingEvent::getMDCPropertyMap);

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

@@ -35,7 +35,7 @@
 import org.springframework.boot.json.JsonWriter.Members;
 import org.springframework.boot.json.WritableJson;
 import org.springframework.boot.logging.structured.CommonStructuredLogFormat;
-import org.springframework.boot.logging.structured.GraylogExtendedLogFormatService;
+import org.springframework.boot.logging.structured.GraylogExtendedLogFormatProperties;
 import org.springframework.boot.logging.structured.JsonWriterStructuredLogFormatter;
 import org.springframework.boot.logging.structured.StructuredLogFormatter;
 import org.springframework.core.env.Environment;
@@ -85,7 +85,7 @@ private static void jsonMembers(Environment environment, ThrowableProxyConverter
 		members.add("_process_pid", environment.getProperty("spring.application.pid", Long.class))
 			.when(Objects::nonNull);
 		members.add("_process_thread_name", ILoggingEvent::getThreadName);
-		GraylogExtendedLogFormatService.get(environment).jsonMembers(members);
+		GraylogExtendedLogFormatProperties.get(environment).jsonMembers(members);
 		members.add("_log_logger", ILoggingEvent::getLoggerName);
 		members.from(ILoggingEvent::getMDCPropertyMap)
 			.when((mdc) -> !CollectionUtils.isEmpty(mdc))

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

@@ -0,0 +1,94 @@
+/*
+ * Copyright 2012-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.logging.structured;
+
+import org.springframework.boot.context.properties.bind.Binder;
+import org.springframework.boot.json.JsonWriter;
+import org.springframework.boot.json.JsonWriter.Members;
+import org.springframework.core.env.Environment;
+import org.springframework.util.StringUtils;
+
+/**
+ * Properties for Elastic Common Schema structured logging.
+ *
+ * @param service service details
+ * @author Moritz Halbritter
+ * @author Phillip Webb
+ * @since 3.4.0
+ */
+public record ElasticCommonSchemaProperties(Service service) {
+
+	static final ElasticCommonSchemaProperties NONE = new ElasticCommonSchemaProperties(Service.NONE);
+
+	ElasticCommonSchemaProperties withDefaults(Environment environment) {
+		Service service = this.service.withDefaults(environment);
+		return new ElasticCommonSchemaProperties(service);
+	}
+
+	static String withFallbackProperty(Environment environment, String value, String property) {
+		return (!StringUtils.hasLength(value)) ? environment.getProperty(property) : value;
+	}
+
+	/**
+	 * Add {@link JsonWriter} members for the service.
+	 * @param members the members to add to
+	 */
+	public void jsonMembers(JsonWriter.Members<?> members) {
+		this.service.jsonMembers(members);
+	}
+
+	/**
+	 * Return a new {@link ElasticCommonSchemaProperties} from bound from properties in
+	 * the given {@link Environment}.
+	 * @param environment the source environment
+	 * @return a new {@link ElasticCommonSchemaProperties} instance
+	 */
+	public static ElasticCommonSchemaProperties get(Environment environment) {
+		return Binder.get(environment)
+			.bind("logging.structured.ecs", ElasticCommonSchemaProperties.class)
+			.orElse(NONE)
+			.withDefaults(environment);
+	}
+
+	/**
+	 * Service details.
+	 *
+	 * @param name the application name
+	 * @param version the version of the application
+	 * @param environment the name of the environment the application is running in
+	 * @param nodeName the name of the node the application is running on
+	 */
+	public record Service(String name, String version, String environment, String nodeName) {
+
+		static final Service NONE = new Service(null, null, null, null);
+
+		void jsonMembers(Members<?> members) {
+			members.add("service.name", this::name).whenHasLength();
+			members.add("service.version", this::version).whenHasLength();
+			members.add("service.environment", this::environment).whenHasLength();
+			members.add("service.node.name", this::nodeName).whenHasLength();
+		}
+
+		Service withDefaults(Environment environment) {
+			String name = withFallbackProperty(environment, this.name, "spring.application.name");
+			String version = withFallbackProperty(environment, this.version, "spring.application.version");
+			return new Service(name, version, this.environment, this.nodeName);
+		}
+
+	}
+
+}

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

@@ -0,0 +1,89 @@
+/*
+ * Copyright 2012-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.logging.structured;
+
+import org.springframework.boot.context.properties.bind.Binder;
+import org.springframework.boot.json.JsonWriter;
+import org.springframework.core.env.Environment;
+import org.springframework.util.StringUtils;
+
+/**
+ * Service details for Graylog Extended Log Format structured logging.
+ *
+ * @param host the application name
+ * @param service the version of the application
+ * @author Samuel Lissner
+ * @author Phillip Webb
+ * @since 3.4.0
+ */
+public record GraylogExtendedLogFormatProperties(String host, Service service) {
+
+	static final GraylogExtendedLogFormatProperties NONE = new GraylogExtendedLogFormatProperties(null, Service.NONE);
+
+	GraylogExtendedLogFormatProperties withDefaults(Environment environment) {
+		String name = withFallbackProperty(environment, this.host, "spring.application.name");
+		Service service = this.service.withDefaults(environment);
+		return new GraylogExtendedLogFormatProperties(name, service);
+	}
+
+	static String withFallbackProperty(Environment environment, String value, String property) {
+		return (!StringUtils.hasLength(value)) ? environment.getProperty(property) : value;
+	}
+
+	/**
+	 * Add {@link JsonWriter} members for the service.
+	 * @param members the members to add to
+	 */
+	public void jsonMembers(JsonWriter.Members<?> members) {
+		members.add("host", this::host).whenHasLength();
+		this.service.jsonMembers(members);
+	}
+
+	/**
+	 * Return a new {@link GraylogExtendedLogFormatProperties} from bound from properties
+	 * in the given {@link Environment}.
+	 * @param environment the source environment
+	 * @return a new {@link GraylogExtendedLogFormatProperties} instance
+	 */
+	public static GraylogExtendedLogFormatProperties get(Environment environment) {
+		return Binder.get(environment)
+			.bind("logging.structured.gelf", GraylogExtendedLogFormatProperties.class)
+			.orElse(NONE)
+			.withDefaults(environment);
+	}
+
+	/**
+	 * Service details.
+	 *
+	 * @param version the version of the application
+	 */
+	public record Service(String version) {
+
+		static final Service NONE = new Service(null);
+
+		Service withDefaults(Environment environment) {
+			String version = withFallbackProperty(environment, this.version, "spring.application.version");
+			return new Service(version);
+		}
+
+		void jsonMembers(JsonWriter.Members<?> members) {
+			members.add("_service_version", this::version).whenHasLength();
+		}
+
+	}
+
+}