/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch licenses this file to you 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
*
* http://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.elasticsearch.common.logging;
import org.apache.logging.log4j.Level;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.core.LoggerContext;
import org.apache.logging.log4j.core.config.AbstractConfiguration;
import org.apache.logging.log4j.core.config.Configurator;
import org.apache.logging.log4j.core.config.builder.api.ConfigurationBuilder;
import org.apache.logging.log4j.core.config.builder.api.ConfigurationBuilderFactory;
import org.apache.logging.log4j.core.config.builder.impl.BuiltConfiguration;
import org.apache.logging.log4j.core.config.composite.CompositeConfiguration;
import org.apache.logging.log4j.core.config.properties.PropertiesConfiguration;
import org.apache.logging.log4j.core.config.properties.PropertiesConfigurationFactory;
import org.apache.logging.log4j.status.StatusConsoleListener;
import org.apache.logging.log4j.status.StatusData;
import org.apache.logging.log4j.status.StatusListener;
import org.apache.logging.log4j.status.StatusLogger;
import org.elasticsearch.cli.ExitCodes;
import org.elasticsearch.cli.UserException;
import org.elasticsearch.cluster.ClusterName;
import org.elasticsearch.common.SuppressForbidden;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.env.Environment;
import org.elasticsearch.node.Node;
import java.io.IOException;
import java.nio.file.FileVisitOption;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.ArrayList;
import java.util.EnumSet;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.stream.StreamSupport;
public class LogConfigurator {
/*
* We want to detect situations where we touch logging before the configuration is loaded. If we do this, Log4j will status log an error
* message at the error level. With this error listener, we can capture if this happens. More broadly, we can detect any error-level
* status log message which likely indicates that something is broken. The listener is installed immediately on startup, and then when
* we get around to configuring logging we check that no error-level log messages have been logged by the status logger. If they have we
* fail startup and any such messages can be seen on the console.
*/
private static final AtomicBoolean error = new AtomicBoolean();
private static final StatusListener ERROR_LISTENER = new StatusConsoleListener(Level.ERROR) {
@Override
public void log(StatusData data) {
error.set(true);
super.log(data);
}
};
/**
* Registers a listener for status logger errors. This listener should be registered as early as possible to ensure that no errors are
* logged by the status logger before logging is configured.
*/
public static void registerErrorListener() {
error.set(false);
StatusLogger.getLogger().registerListener(ERROR_LISTENER);
}
/**
* Configure logging without reading a log4j2.properties file, effectively configuring the
* status logger and all loggers to the console.
*
* @param settings for configuring logger.level and individual loggers
*/
public static void configureWithoutConfig(final Settings settings) {
Objects.requireNonNull(settings);
// we initialize the status logger immediately otherwise Log4j will complain when we try to get the context
configureStatusLogger();
configureLoggerLevels(settings);
}
/**
* Configure logging reading from any log4j2.properties found in the config directory and its
* subdirectories from the specified environment. Will also configure logging to point the logs
* directory from the specified environment.
*
* @param environment the environment for reading configs and the logs path
* @throws IOException if there is an issue readings any log4j2.properties in the config
* directory
* @throws UserException if there are no log4j2.properties in the specified configs path
*/
public static void configure(final Environment environment) throws IOException, UserException {
Objects.requireNonNull(environment);
try {
// we are about to configure logging, check that the status logger did not log any error-level messages
checkErrorListener();
} finally {
// whether or not the error listener check failed we can remove the listener now
StatusLogger.getLogger().removeListener(ERROR_LISTENER);
}
configure(environment.settings(), environment.configFile(), environment.logsFile());
}
private static void checkErrorListener() {
assert errorListenerIsRegistered() : "expected error listener to be registered";
if (error.get()) {
throw new IllegalStateException("status logger logged an error before logging was configured");
}
}
private static boolean errorListenerIsRegistered() {
return StreamSupport.stream(StatusLogger.getLogger().getListeners().spliterator(), false).anyMatch(l -> l == ERROR_LISTENER);
}
private static void configure(final Settings settings, final Path configsPath, final Path logsPath) throws IOException, UserException {
Objects.requireNonNull(settings);
Objects.requireNonNull(configsPath);
Objects.requireNonNull(logsPath);
setLogConfigurationSystemProperty(logsPath, settings);
// we initialize the status logger immediately otherwise Log4j will complain when we try to get the context
configureStatusLogger();
final LoggerContext context = (LoggerContext) LogManager.getContext(false);
final List<AbstractConfiguration> configurations = new ArrayList<>();
final PropertiesConfigurationFactory factory = new PropertiesConfigurationFactory();
final Set<FileVisitOption> options = EnumSet.of(FileVisitOption.FOLLOW_LINKS);
Files.walkFileTree(configsPath, options, Integer.MAX_VALUE, new SimpleFileVisitor<Path>() {
@Override
public FileVisitResult visitFile(final Path file, final BasicFileAttributes attrs) throws IOException {
if (file.getFileName().toString().equals("log4j2.properties")) {
configurations.add((PropertiesConfiguration) factory.getConfiguration(context, file.toString(), file.toUri()));
}
return FileVisitResult.CONTINUE;
}
});
if (configurations.isEmpty()) {
throw new UserException(
ExitCodes.CONFIG,
"no log4j2.properties found; tried [" + configsPath + "] and its subdirectories");
}
context.start(new CompositeConfiguration(configurations));
configureLoggerLevels(settings);
}
private static void configureStatusLogger() {
final ConfigurationBuilder<BuiltConfiguration> builder = ConfigurationBuilderFactory.newConfigurationBuilder();
builder.setStatusLevel(Level.ERROR);
Configurator.initialize(builder.build());
}
/**
* Configures the logging levels for loggers configured in the specified settings.
*
* @param settings the settings from which logger levels will be extracted
*/
private static void configureLoggerLevels(final Settings settings) {
if (ESLoggerFactory.LOG_DEFAULT_LEVEL_SETTING.exists(settings)) {
final Level level = ESLoggerFactory.LOG_DEFAULT_LEVEL_SETTING.get(settings);
Loggers.setLevel(ESLoggerFactory.getRootLogger(), level);
}
final Map<String, String> levels = settings.filter(ESLoggerFactory.LOG_LEVEL_SETTING::match).getAsMap();
for (final String key : levels.keySet()) {
// do not set a log level for a logger named level (from the default log setting)
if (!key.equals(ESLoggerFactory.LOG_DEFAULT_LEVEL_SETTING.getKey())) {
final Level level = ESLoggerFactory.LOG_LEVEL_SETTING.getConcreteSetting(key).get(settings);
Loggers.setLevel(ESLoggerFactory.getLogger(key.substring("logger.".length())), level);
}
}
}
/**
* Set system properties that can be used in configuration files to specify paths and file patterns for log files. We expose three
* properties here:
* <ul>
* <li>
* {@code es.logs.base_path} the base path containing the log files
* </li>
* <li>
* {@code es.logs.cluster_name} the cluster name, used as the prefix of log filenames in the default configuration
* </li>
* <li>
* {@code es.logs.node_name} the node name, can be used as part of log filenames (only exposed if {@link Node#NODE_NAME_SETTING} is
* explicitly set)
* </li>
* </ul>
*
* @param logsPath the path to the log files
* @param settings the settings to extract the cluster and node names
*/
@SuppressForbidden(reason = "sets system property for logging configuration")
private static void setLogConfigurationSystemProperty(final Path logsPath, final Settings settings) {
System.setProperty("es.logs.base_path", logsPath.toString());
System.setProperty("es.logs.cluster_name", ClusterName.CLUSTER_NAME_SETTING.get(settings).value());
if (Node.NODE_NAME_SETTING.exists(settings)) {
System.setProperty("es.logs.node_name", Node.NODE_NAME_SETTING.get(settings));
}
}
}