Stable logging API - the basic use case (#86612)

Introducing a stable logging API under libs/logging. This change covers the most common use cases for logging: fetching a logger with LogManager, emitting a log messages with Logger and Level. It is influenced by log4j2-api, but do not include Marker and LogBuilder methods. Also methods using org.apache.logging.log4j.util.Supplier are replaced with java.util.Supplier The basic implementation is present in server and injected statically in LogConfigurator relates #84478

Author: pgomulka

build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/InternalDistributionModuleCheckTaskProvider.java

@@ -52,6 +52,7 @@ public class InternalDistributionModuleCheckTaskProvider {
  "org.elasticsearch.base",
  "org.elasticsearch.cli",
  "org.elasticsearch.geo",
+ "org.elasticsearch.logging",
  "org.elasticsearch.lz4",
  "org.elasticsearch.pluginclassloader",
  "org.elasticsearch.securesm",

docs/changelog/86612.yaml

@@ -0,0 +1,5 @@
+pr: 86612
+summary: Stable logging API - the basic use case
+area: Infra/Logging
+type: feature
+issues: []

libs/logging/build.gradle

@@ -0,0 +1,29 @@
+import org.elasticsearch.gradle.transform.UnzipTransform
+
+import java.util.stream.Collectors
+
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+apply plugin: 'elasticsearch.publish'
+apply plugin: 'elasticsearch.build'
+
+
+tasks.named("loggerUsageCheck").configure {enabled = false }
+
+dependencies {
+ testImplementation(project(":test:framework")) {
+ exclude group: 'org.elasticsearch', module: 'elasticsearch-logging'
+ }
+}
+
+
+tasks.named('forbiddenApisMain').configure {
+ // :libs:elasticsearch-logging does not depend on server
+ replaceSignatureFiles 'jdk-signatures'
+}

libs/logging/src/main/java/module-info.java

@@ -0,0 +1,12 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+module org.elasticsearch.logging {
+ exports org.elasticsearch.logging;
+ exports org.elasticsearch.logging.internal.spi to org.elasticsearch.server;
+}

libs/logging/src/main/java/org/elasticsearch/logging/Level.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+package org.elasticsearch.logging;
+
+/**
+ * Levels used for identifying the severity of an event and filtering the logging output.
+ */
+public enum Level {
+
+ /**
+ * No events will be logged.
+ */
+ OFF,
+ /**
+ * A fatal error that will prevent the application from continuing.
+ */
+ FATAL,
+ /**
+ * An error in the application, possibly recoverable.
+ */
+ ERROR,
+ /**
+ * An event that might lead to an error.
+ */
+ WARN,
+ /**
+ * An event for informational purposes.
+ */
+ INFO,
+ /**
+ * A general debugging event.
+ */
+ DEBUG,
+ /**
+ * A fine-grained debug message, typically capturing the flow through the application.
+ */
+ TRACE,
+ /**
+ * All events should be logged.
+ */
+ ALL;
+}

libs/logging/src/main/java/org/elasticsearch/logging/LogManager.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+package org.elasticsearch.logging;
+
+import org.elasticsearch.logging.internal.spi.LoggerFactory;
+
+/**
+ * A Manager of {@code Loggers}. This class consists of factory methods for creating and retrieving Loggers.
+ */
+public final class LogManager {
+
+ /**
+ * Returns a Logger with the specified name.
+ *
+ * @param name The logger name.
+ * @return The Logger.
+ */
+ public static Logger getLogger(final String name) {
+ return LoggerFactory.provider().getLogger(name);
+ }
+
+ /**
+ * Returns a Logger using the fully qualified name of the Class as the Logger name.
+ *
+ * @param clazz The Class whose name should be used as the Logger name.
+ * @return The Logger.
+ */
+ public static Logger getLogger(final Class<?> clazz) {
+ return LoggerFactory.provider().getLogger(clazz);
+ }
+
+ private LogManager() {}
+}