Base Context

You can specify items to add to every Klogging log event in your application. Examples might be application name or a build identifier.

Specify them using the Context object, for example:

const val APP_NAME_KEY = "appName"
const val APP_NAME = "analysis-service"
const val BUILD_NUMBER_KEY = "buildNumber"
const val BUILD_NUMBER_ENV = "BUILD_NUMBER"

Context.addBaseContext(
    APP_NAME_KEY to APP_NAME,
    BUILD_NUMBER_KEY to System.getenv(BUILD_NUMBER_ENV),
)

Log events include those values, for example:

{
  "@t": "2022-06-16T08:52:12.064882Z",
  "@l": "INFO",
  "@mt": "Execution time {elapsedMs} ms",
  "host": "09b4396db8ae",
  "appName": "analysis-service",
  "buildNumber": "2.4.0-d22d0dd",
  "logger": "com.wodgeworks.analysis.RunTimer",
  "elapsedMs": "73",
  "run": "a6f72c37-7e2f-4d69-a73f-7f493cb04d1d",
  "context": "DefaultDispatcher-worker-3"
}

From other coroutine context elements

Klogging can include information from other coroutine context elements.

As an example, if your application is using Project Reactor, you can store information in a Reactor Context and wrap that in a coroutine ReactorContext.

Configure Klogging to use all the values from the Reactor context in log events (EventItems is a convenient type alias for Map<String, Any?>):

import io.klogging.config.Context
import io.klogging.events.EventItems
import kotlinx.coroutines.reactor.ReactorContext

val reactorExtractor: (ReactorContext) -> EventItems = { ctx ->
    // TBC
}

Context.addContextItemExtractor(ReactorContext, reactorExtractor)

Any log events emitted within the scope of the Reactor context will include items returned by the reactorExtractor() function from that context.

Base Context

From other coroutine context elements​

From other coroutine context elements