logback-journal

systemd journal appender for Logback.

Installation

logback-journal appender is published in Sonatype Maven Central Repository.

If you are using Maven, simply add the following in your pom.xml

<dependency>
  <groupId>com.dgkncgty</groupId>
  <artifactId>logback-journal</artifactId>
  <version>0.5.0</version>
</dependency>

If you are using Gradle, add this to your build.gradle

implementation 'com.dgkncgty:logback-journal:0.5.0'

if you are using sbt, add this to your build.sbt

libraryDependencies += "com.dgkncgty" % "logback-journal" % "0.5.0"

You also need the systemd journal library installed on your system to log to it.

For newest version of systemd, journal is integrated in the systemd base library. Older version had a separate library named systemd-journal. This appender use systemd as a library by default. You can change this by using the systemd.library JVM property (e.g. -Dsystemd.library=systemd-journal)

Configuration

Basic configuration to use the systemd journal appender looks like this:

<configuration>

  <appender name="journal" class="com.dgkncgty.logback.SystemdJournalAppender" />

  <root level="debug">
    <appender-ref ref="journal" />
  </root>
</configuration>

The appender can be configured with the following properties

Property name	Type	Description	Default Value
logLocation	boolean	Determines whether the exception locations are logged when present. This data is logged in standard systemd journal fields CODE_FILE, CODE_LINE and CODE_FUNC.	true
logSourceLocation	boolean	Determines whether the source locations are logged when present. Note that there is a performance overhead when switched on. This data is logged in standard systemd journal fields CODE_FILE, CODE_LINE and CODE_FUNC.	false
logException	boolean	Determines whether the exception name and messages are logged. This data is logged in the user fields EXN_NAME and EXN_MESSAGE.	true
logStackTrace	boolean	Determines whether the exception stack trace is logged. This data is logged in the user field EXN_STACKTRACE.	false
logThreadName	boolean	Determines whether the thread name is logged. This data is logged in the user field THREAD_NAME.	true
logLoggerName	boolean	Determines whether the logger name is logged. This data is logged in the user field LOGGER_NAME.	false
logMdc	boolean	Determines whether the MDC content is logged. Each key/value pair is logged as user field with the mdcKeyPrefix prefix.	false
mdcKeyPrefix	String	Determines how MDC keys should be prefixed when logMdc is set to true. Note that keys need to match the regex pattern [A-Z0-9_]+ and are normalized otherwise.	""
syslogIdentifier	String	Overrides the syslog identifier string. This data is logged in the user field SYSLOG_IDENTIFIER.	The process name (i.e. "java")