Getting Slick 3.x + Kamon 1.x to stop forgetting the context

AsyncExecutorContextAware.scala

//based on https://github.com/kamon-io/Kamon/issues/311

class AsyncExecutorContextAware(underlying: AsyncExecutor) extends AsyncExecutor {
  override def executionContext: ExecutionContext = new ExecutionContextAware(underlying.executionContext)
  override def close(): Unit                      = underlying.close()
}

class ExecutionContextAware(underlying: ExecutionContext) extends ExecutionContext {
  override def execute(runnable: Runnable): Unit     = underlying.execute(new RunnableContextAware(runnable))
  override def reportFailure(cause: Throwable): Unit = underlying.reportFailure(cause)
}

class RunnableContextAware(underlying: Runnable) extends Runnable {
  private val traceContext = Kamon.currentContext

  override def run(): Unit = {
    Kamon.withContext(traceContext) {
      underlying.run()
    }
  }
}

//then use it to create your Database instance, e.g.
Database.forUrl(???, new AsyncExecutorContextAware(AsyncExecutor.default()))