filebeat如何根据document type 映射到redis的多个key中

按照Filebeat redis output 插件的文档https://www.elastic.co/guide/e ... _keys，是支持keys的。也就是这样使用：

output.redis:

  hosts: ["localhost"]

  key: "default_list"

  keys:

    - key: "info_list"   # send to info_list if `message` field contains INFO

      when.contains:

        message: "INFO"

    - key: "debug_list"  # send to debug_list if `message` field contains DEBUG

      when.contains:

        message: "DEBUG"

    - key: "%{[type]}"

      mapping:

        "http": "frontend_list"

        "nginx": "frontend_list"

        "mysql": "backend_list"

但是我按照这样的写法，当document_type为http时，到达redis的数据的key仍然是http，而不是frontend_lit