Playing/testing with logback configuration. / published by https://github.com/dacr/code-examples-manager #b45b0038-e0fc-4dd5-810f-5ad9b420f41e/160f7f5e1ce02df1e29f81405c8d10a742acc219

logging-testing.sc

// summary : Playing/testing with logback configuration.
// keywords : scala, scalatest, logs, logback, @testable
// publish : gist
// authors : David Crosson
// license : Apache2
// id : b45b0038-e0fc-4dd5-810f-5ad9b420f41e
// created-on : 2020-05-31T19:54:52Z
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala  "3.1.1"
//> using lib "org.scalatest::scalatest:3.2.10"
//> using lib "ch.qos.logback:logback-classic:1.2.3"
//> using lib "net.logstash.logback:logstash-logback-encoder:5.2"
// ---------------------

import org.scalatest._, flatspec._, matchers._
import org.slf4j._


trait LogBackHelpers {
  def configureLogBack(xmlConfig:String):Unit = {
    val loggerContext = LoggerFactory.getILoggerFactory.asInstanceOf[ch.qos.logback.classic.LoggerContext]
    loggerContext.reset()
    val configurator = new ch.qos.logback.classic.joran.JoranConfigurator()
    val configStream = new java.io.ByteArrayInputStream(xmlConfig.getBytes)
    configurator.setContext(loggerContext)
    configurator.doConfigure(configStream) // loads logback file
  }

  def getRootLogger():ch.qos.logback.classic.Logger = {
    LoggerFactory.getLogger(Logger.ROOT_LOGGER_NAME).asInstanceOf[ch.qos.logback.classic.Logger]
  }

  def configureDebugRootLogger():java.io.InputStream = {
    val loggerContext = LoggerFactory.getILoggerFactory.asInstanceOf[ch.qos.logback.classic.LoggerContext]
    loggerContext.reset()
    val rootLogger = getRootLogger()
    val output = new java.io.PipedOutputStream()

    val encoder = new ch.qos.logback.classic.encoder.PatternLayoutEncoder()
    encoder.setPattern("%date %level [%thread] %logger{10} [%file:%line] - %msg%n")
    encoder.setContext(loggerContext)

    val outputStreamAppender = new ch.qos.logback.core.OutputStreamAppender[ch.qos.logback.classic.spi.ILoggingEvent]()
    outputStreamAppender.setContext(loggerContext)
    outputStreamAppender.setOutputStream(output)
    outputStreamAppender.setEncoder(encoder)

    rootLogger.addAppender(outputStreamAppender)

    new java.io.PipedInputStream(output)
  }
}




class LoggingTesting extends AnyFlatSpec with should.Matchers with LogBackHelpers {
  override val suiteName = "LoggingTesting"

  // -------------------------------------------------------------------------------------------------
  "logback" should "allow to programmically change default ROOT logger configuration" in {
    val rootLogger = getRootLogger()
    rootLogger.setLevel(ch.qos.logback.classic.Level.ERROR)
    rootLogger.getLevel shouldBe ch.qos.logback.classic.Level.ERROR
  }

  // -------------------------------------------------------------------------------------------------
  it should "be configurable through a xml configuration" in {
    val config=
      """<configuration scan="false" scanPeriod="10 seconds">
        | <root level="INFO">
        |    <appender-ref ref="FILE"/>
        | </root>
        |</configuration>""".stripMargin
    configureLogBack(config)
    getRootLogger().getLevel shouldBe ch.qos.logback.classic.Level.INFO
  }

  // -------------------------------------------------------------------------------------------------
  it should "raise an exception with an invalid configuration file" in {
    val config=
      """<configuration scan="false" scanPeriod="10 seconds">
        | <rootx level="INFO">
        |    <appender-ref ref="FILE"/>
        | </root>
        |</configuration>""".stripMargin
    intercept[Exception] {
      configureLogBack(config)
    }
  }

  // -------------------------------------------------------------------------------------------------
  ignore should "be possible to use a memory appender" in {
    val logInputStream = configureDebugRootLogger()
    val logEntries = scala.io.Source.fromInputStream(logInputStream)
    val logger = LoggerFactory.getLogger("Test")
    logger.info("HELLO")
    logEntries.getLines.next should include regex "(?i)hello"
  }

  // -------------------------------------------------------------------------------------------------
  it should "insert exception stack trace digest" in {
    val logFileName="testFile.log"
    val config =
      """<?xml version="1.0" encoding="UTF-8"?>
        |<!-- application logging configuration to ship logs directly to Logstash -->
        |<configuration>
        |  <!-- define stack trace element exclusion patterns as a global property -->
        |  <property name="STE_EXCLUSIONS" value="^ammonite\.,\$\$FastClassByCGLIB\$\$,\$\$EnhancerBySpringCGLIB\$\$,^sun\.reflect\..*\.invoke,^com\.sun\.,^sun\.net\.,^net\.sf\.cglib\.proxy\.MethodProxy\.invoke,^org\.junit\.,^org\.apache\.maven\.surefire\.,^java\.lang\.reflect\.Method\.invoke,^java\.util\.concurrent\.ThreadPoolExecutor\.runWorker,^java\.lang\.Thread\.run"/>
        |
        |  <conversionRule conversionWord="sEx" converterClass="net.logstash.logback.stacktrace.ShortenedThrowableConverter" />
        |
        |<appender name="FILE" class="ch.qos.logback.core.FileAppender">
        |    <file>{{LOG_FILE_NAME}}</file>
        |    <append>false</append>
        |    <immediateFlush>true</immediateFlush>
        |    <encoder>
        |        <conversionRule conversionWord="exId"
        |           converterClass="net.logstash.logback.stacktrace.ShortenedThrowableConverter" />
        |        <pattern>
        |          %-4relative [%thread] %-5level %logger{35} - %msg - %sEx{3,full,full,inlineHash,${STE_EXCLUSIONS}}%n
        |        </pattern>
        |        <!-- computes and adds a 'stack_hash' field on errors -->
        |        <provider class="net.logstash.logback.composite.loggingevent.StackHashJsonProvider">
        |            <!-- use global property for exclusion patterns -->
        |            <exclusions>${STE_EXCLUSIONS}</exclusions>
        |        </provider>
        |        <!-- enriches the stack trace with unique hash -->
        |        <throwableConverter class="net.logstash.logback.stacktrace.ShortenedThrowableConverter">
        |            <!-- compute and inline hash in stack trace -->
        |            <inlineHash>true</inlineHash>
        |            <!-- use global property for exclusion patterns -->
        |            <exclusions>${STE_EXCLUSIONS}</exclusions>
        |        </throwableConverter>
        |    </encoder>
        |  </appender>
        |
        |  <logger name="Test" level="DEBUG" />
        |
        |  <root level="INFO">
        |    <appender-ref ref="FILE" />
        |  </root>
        |
        |</configuration>""".stripMargin.replaceAll("""\{\{LOG_FILE_NAME\}\}""", logFileName)
    configureLogBack(config)
    val logger = LoggerFactory.getLogger("Test")
    logger.info("started")
    logger.error("something wrong", new Exception("bad"))
    logger.error("something wrong", new Exception("bad"))
    logger.debug("debug message")
    val logFileContent = scala.io.Source.fromFile(logFileName).getLines.toList.mkString("\n")
    logFileContent should include regex """(?i)<#[A-F0-9]+>"""
  }
}

org.scalatest.tools.Runner.main(Array("-oDF", "-s", classOf[LoggingTesting].getName))