为Docker的gcplogs日志驱动程序设置Stackdriver Logging日志级别

Question

Docker支持将--log-driver=gcplogsGoogle Compute Engine实例记录到Stackdriver Logging服务（也称为Google Cloud Logging）的选项。但是，位于https://console.cloud.google.com/logs的“日志查看器”页面中的所有日志条目都没有严重性级别-整个日志行都放置在如下data字段中：

{
  metadata: {
    projectId: "my-project"
    serviceName: "custom.googleapis.com"
    labels: {
      custom.googleapis.com/secondary_key: "secondary_key"
      custom.googleapis.com/primary_key: "primary_key"
    }
    timestamp: "2016-05-10T00:07:28.700617425Z"
    projectNumber: "12345"
  }
  insertId: "2016-05-09|17:07:28.706161-07|1.2.3.4|1234"
  log: "gcplogs-docker-driver"
  structPayload: {
    container: {
      imageName: "us.gcr.io/my-image/name"
      created: "2016-05-09T15:09:15.15158629Z"
      name: "/my-container"
      id: "7b6f9fa1d7517e6a3004b8fa7e52asdfddd8e63d02e43afb3942681a56f4e"
      imageId: "sha256:20605d3fdc700asdfa8b08a4aed1f745a0b5d9a8f08ae0db2f90af0bd093"
    }
    data: "2016-05-10 00:07:28,700 DEBUG [my-file:191][uWSGIWorker1Core0] Some log message here"
    instance: {
      zone: "us-east1-b"
      name: "broker-1"
      id: "12345"
    }
  }
}

我知道Docker会记录容器的stdout和stderr，但是如何配置事物（Docker，Compute Engine，Stackdriver Logging）来解析消息以具有日志级别？