TaggedLogger

data class MyServiceLogger<T: Any>(
  val loggerClass: KClass<T>,
  val tags: Set<Tag> = emptySet()
): TaggedLogger<T, MyServiceLogger<T>>(loggerClass, tags) {
  fun processValue(value: String?) = tag("process_value" to value)

  override fun copyWithNewTags(newTags: Set<Tag>): MyServiceLogger<T>
    = this.copy(tags = newTags)
}

fun <T : Any> KClass<T>.getTaggedLogger(): MyServiceLogger<T> {
  return MyServiceLogger(this)
}

class ServiceAction (private val webClient: WebClient): WebAction {

  @Post("/api/resource")
  fun executeWebAction(@RequestBody request: ServiceActionRequest) {
    logger
      .processValue(request.process_value)
      .asContext() {
        logger.info() { "Received request" }
        doSomething()
      }
  }

  private fun doSomething() {
    logger.info() { "Start Process" }

    client.someWebRequest() // Client throws exception to be caught and logged by misk framework

    logger.info() { "Done" }
  }

  companion object {
    val logger = this::class.getTaggedLogger()
  }
}

Log MDC context: [process_value: PV_123] Log message: "Received request"
Log MDC context: [process_value: PV_123] Log message: "Start Process"
Log MDC context: [process_value: PV_123] Log message: "unexpected error dispatching to ServiceAction" // This log would not normally include the MDC context