Google Cloud Logs for Scala ZIO2 Apps on Kubernetes

README.md

How to add Google Cloud Logging for Kubernetes to a Scala ZIO2 Application

This is based on the google logback appender docs: https://cloud.google.com/logging/docs/setup/java

• Add the google-cloud-logging-logback to your sbt file see example.
  • If you don't already have the slf4j and zio logging libs add those as well.
• Add the logback.xml appender below this has been scoped for k8s_container.
• If you haven't use the slf4j appender ZLayer in your main application see the example for a ZIOAppDefault app below.

build.sbt

val googleCloudLoggingLogback = "0.127.8-alpha"
//...
Seq(
//...
/**
 *  "dev.zio"             %% "zio-logging"              % zioLoggingVersion,
 *  "dev.zio"             %% "zio-logging-slf4j"        % zioLoggingVersion,
 *  "ch.qos.logback"       % "logback-classic"          % logbackClassicVersion,
 */
"com.google.cloud"      % "google-cloud-logging-logback" % googleCloudLoggingLogback //, ...
)

logback.xml

<configuration>
    <appender name="CLOUD" class="com.google.cloud.logging.logback.LoggingAppender">
        <log>my-app-name.log</log>
        <resourceType>k8s_container</resourceType>
        <flushLevel>WARN</flushLevel>
        <redirectToStdout>true</redirectToStdout>
        <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
            <level>INFO</level>
        </filter>
    </appender>


    <root level="INFO">
        <appender-ref ref="CLOUD" />
    </root>

</configuration>

myapp.scala

object MyApp extends ZIOAppDefault {
   // This is the line that gets the slf4j loggers to work with zio2 logging.
   override val bootstrap: ZLayer[Any, Nothing, Unit] = Runtime.removeDefaultLoggers ++ SLF4J.slf4j
  
  
}