将@metadata从logstash发送到弹性搜索

Question

我有以下logstash配置，我正在尝试将RabbitMQ标头（存储在@metadata字段中）发送到ElasticSearch

input {
    rabbitmq {
        auto_delete => false
        durable => false
        host => "my_host"
        port => 5672
        queue => "my_queue"
        key => "#"      
        threads => 1
        codec => "plain"
        user => "user"
        password => "pass"
        metadata_enabled => true
    }
}

filter {
    ???
}

output {
    stdout { codec => rubydebug {metadata => true} }
    elasticsearch { hosts => localhost }
}

我可以在std输出中看到标题

{
    "@timestamp" => 2017-07-11T15:53:28.629Z,
     "@metadata" => {
           "rabbitmq_headers" => { "My_Header" => "My_value"
        },
        "rabbitmq_properties" => {
            "content-encoding" => "utf-8",
              "correlation-id" => "785901df-e954-4735-a9cf-868088fdac87",
                "content-type" => "application/json",
                    "exchange" => "My_Exchange",
                 "routing-key" => "123-456",
                "consumer-tag" => "amq.ctag-ZtX3L_9Zsz96aakkSGYzGA"
        }
    },
      "@version" => "1",
       "message" => "{...}"

是否有一些过滤器（grok，mutate，kv等）可以将这些值复制到发送给ElasticSearch的消息中的标签？