How can I configure system properties or logback configuration variables from typesafe config?

Question

I have variables with defaults in my logback.xml configuration file, and I would like to be able to optionally set these variables from my typesafe config application.conf file.

I am deploying the application using one-jar, and the application.conf file packaged up in the deployable jar contains defaults. I pass -Dconfig.file=foo.conf on execution to provide the path to a server-specific config file.

Right now I can also pass -Dlog.level and other variables to override my defaults in logback.xml, and I also have to pass -Dfile.encoding=UTF-8 on the command line. I'm looking for a way to be able to specify these properties in the typesafe config instead of on the command line. It feels like there should be a way to do it, but I can't find the magic words.

logback.xml:

<configuration>
    <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${log.path:-logs/}/${log.file:-myLog.log}</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <!-- daily rollover -->
            <fileNamePattern>logFile.%d{yyyy-MM-dd}.log</fileNamePattern>

            <!-- keep 15 days' worth of history -->
            <maxHistory>${log.history.days:-15}</maxHistory>
        </rollingPolicy>

        <encoder>
            <pattern>%-4relative [%thread] %-5level %logger{35} - %msg%n</pattern>
        </encoder>
    </appender>

    <root level="${log.level:-INFO}">
        <appender-ref ref="FILE" />
    </root>
</configuration>

application.conf (bundled):

akka {
    log-config-on-start = false
    event-handlers = ["akka.event.slf4j.Slf4jEventHandler"]
}

sample server-specific app.conf:

include "/application.conf"

akka.log-config-on-start = true

log.level = WARN // this is what I'd LIKE to be able to do

How I'm currently running the app:

java -Dfile.encoding=UTF-8 -Dconfig.file=myApp.conf -Dlog.level=WARN -jar myApp_2.10-0.1-one-jar.jar 

Answer 1

I chose to programmatically configure logback having typesafe config. It turned out to be easy.

def enableRemoteLogging(config: Config) = {
    val ctx = LoggerFactory.getILoggerFactory.asInstanceOf[LoggerContext]

    val gelf = new GelfAppender
    gelf.setGraylog2ServerHost(config.getString("logging.remote.server"))
    gelf.setUseLoggerName(true)
    gelf.setUseThreadName(true)
    gelf.setUseMarker(true)
    gelf.setIncludeFullMDC(true)
    gelf.setContext(ctx)
    gelf.start()

    LoggerFactory.getLogger(Logger.ROOT_LOGGER_NAME)
      .asInstanceOf[ch.qos.logback.classic.Logger]
      .addAppender(gelf)
  }