Actuator loggers list endpoint throws exception on Log4J2 loggers with custom log levels #35227
Description
We are using Log4j as our logging framework. One of our loggers has custom Log level. When calling actuator /loggers endpoint to get list of all loggers exception raises:
EffectiveLevel must not be null
This error is from LoggerConfiguration class constructor which doesnt let null values on effectiveLevel variable:
public LoggerConfiguration(String name, LogLevel configuredLevel, LogLevel effectiveLevel) {
Assert.notNull(name, "Name must not be null");
Assert.notNull(effectiveLevel, "EffectiveLevel must not be null");
this.name = name;
this.configuredLevel = configuredLevel;
this.effectiveLevel = effectiveLevel;
}but the real problem comes when calling this class constructor. in Log4J2LoggingSystem.convertLoggerConfig:
private LoggerConfiguration convertLoggerConfig(String name, LoggerConfig loggerConfig) {
if (loggerConfig == null) {
return null;
}
LogLevel level = LEVELS.convertNativeToSystem(loggerConfig.getLevel());
if (!StringUtils.hasLength(name) || LogManager.ROOT_LOGGER_NAME.equals(name)) {
name = ROOT_LOGGER_NAME;
}
boolean isLoggerConfigured = loggerConfig.getName().equals(name);
LogLevel configuredLevel = (isLoggerConfigured) ? level : null;
return new LoggerConfiguration(name, configuredLevel, level);
}The LEVELS variable:
private static final LogLevels<Level> LEVELS = new LogLevels<>();
static {
LEVELS.map(LogLevel.TRACE, Level.TRACE);
LEVELS.map(LogLevel.DEBUG, Level.DEBUG);
LEVELS.map(LogLevel.INFO, Level.INFO);
LEVELS.map(LogLevel.WARN, Level.WARN);
LEVELS.map(LogLevel.ERROR, Level.ERROR);
LEVELS.map(LogLevel.FATAL, Level.FATAL);
LEVELS.map(LogLevel.OFF, Level.OFF);
}is like above. Our custom log level doesn't exist in this Map. so this line returns null
LogLevel level = LEVELS.convertNativeToSystem(loggerConfig.getLevel());and we get the exception.