Play 2.6x Scala app does not log despite logback configuration - scala

Question

I'm trying to enable logging in my Play 2.6 Scala app.
I've basically implemented this logging filter to log each request processed by the server: https://www.playframework.com/documentation/2.6.x/ScalaHttpFilters.
I cannot for the life of me get the logs to show in either the console OR the specific log/ directory. I've tried everything from playing around with my logback.xml file and my app config.
Does anyone have any ideas where I'm going wrong? The filter I wrote is being processed on request (I set a breakpoint to ensure).
logback.xml:
<!-- https://www.playframework.com/documentation/latest/SettingsLogger -->
<configuration>
<conversionRule conversionWord="coloredLevel" converterClass="play.api.libs.logback.ColoredLevel" />
<appender name="FILE" class="ch.qos.logback.core.FileAppender">
<file>${application.home:-.}/logs/application.log</file>
<encoder>
<pattern>%date [%level] from %logger in %thread - %message%n%xException</pattern>
</encoder>
</appender>
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>%coloredLevel %logger{15} - %message%n%xException{10}</pattern>
</encoder>
</appender>
<appender name="ASYNCFILE" class="ch.qos.logback.classic.AsyncAppender">
<appender-ref ref="FILE" />
</appender>
<appender name="ASYNCSTDOUT" class="ch.qos.logback.classic.AsyncAppender">
<appender-ref ref="STDOUT" />
</appender>
<logger name="play" level="INFO" />
<logger name="application" level="DEBUG" />
<!-- Off these ones as they are annoying, and anyway we manage configuration ourselves -->
<logger name="com.avaje.ebean.config.PropertyMapLoader" level="OFF" />
<logger name="com.avaje.ebeaninternal.server.core.XmlConfigLoader" level="OFF" />
<logger name="com.avaje.ebeaninternal.server.lib.BackgroundThread" level="OFF" />
<!--<logger name="org.jdbcdslog.StatementLogger" level="DEBUG" /> <!– Will log all statements –>-->
<!--<logger name="slick.jdbc.JdbcBackend.statement" level="DEBUG" />-->
<logger name="com.gargoylesoftware.htmlunit.javascript" level="OFF" />
<root level="INFO">
<appender-ref ref="ASYNCFILE" />
<appender-ref ref="ASYNCSTDOUT" />
</root>
</configuration>
LoggingFilter.scala:
package filters
import javax.inject.Inject
import akka.stream.Materializer
import play.api.Logger
import play.api.mvc._
import scala.concurrent.{ExecutionContext, Future}
class LoggingFilter #Inject() (implicit val mat: Materializer, ec: ExecutionContext) extends Filter {
def apply(nextFilter: RequestHeader => Future[Result])
(requestHeader: RequestHeader): Future[Result] = {
Logger.debug("Hi!") // Why you no work!!
val startTime = System.currentTimeMillis
nextFilter(requestHeader).map { result =>
val endTime = System.currentTimeMillis
val requestTime = endTime - startTime
Logger.info(s"${requestHeader.method} ${requestHeader.uri} took ${requestTime}ms and returned ${result.header.status}")
result.withHeaders("Request-Time" -> requestTime.toString)
}
}
}

Answer 1

Well, after several hours of debugging, I finally found the cause (could be helpful for others so posting here).
Cause:
The root cause of the issue is a conflicting logging dependency bundled in play-silhoutte. My app was using play-silhoutte version 5.0.3 which apparently contains a bug causing the Play logger to be overwritten by a logging configuration in a sub-dependency of play-silhoutte(com.typesafe.play:play-openid_2.12:2.6.9).
Diagnosis:
Unfortunately this took a long time to debug - combination of reading Play source code + debugging the stack frames as the Logger gets initialized. I noticed that the Logger was being initialized twice - once for the actual Play logger (with correct configuration as specified in my logback.xml then again as a result of play-silhoutte (effectively overwriting the good logger).
Looking at the initialization params, it was reading its logback.xml from /Users/.../.ivy2/cache/com.typesafe.play/play-openid_2.12/jars/play-openid_2.12-2.6.9.jar!logback.xml. I expanded the jar and found the following logging config:
<!--
~ Copyright (C) 2009-2017 Lightbend Inc. <https://www.lightbend.com>
-->
<configuration>
<!-- Suppress logback complaining about multiple logback-test.xml files -->
<statusListener class="ch.qos.logback.core.status.NopStatusListener" />
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<!-- We use short exception stack trace logging to limit output for travis. -->
<!-- Change to full if you need to do further debugging, but never commit that. -->
<pattern>%level %logger{15} - %message%n%ex{short}</pattern>
</encoder>
</appender>
<root level="WARN">
<appender-ref ref="STDOUT" />
</root>
</configuration>
At this point I knew it was a conflicting depedency issue.
Solution:
After doing some digging, I actually found a bug open on Github describing my issue. I was running play-silhoutte version 5.0.3 so bumping it to 5.0.4 fixed the issue.