elasticsearch ElasticSearch/Logstash：动态映射错误

我已经安装了ES集群和Logstash。 我有很多信息的输入类型。现在我对Gelf输入类型有问题。我需要将ES中的所有字段存储为字符串，但如果我在gelf“message”字段中有json，ES将从此json创建新的映射。我不想要它，我尝试了很多变体来禁用“message”字段的动态映射。 日志存储模板配置：

 {
   "mappings":{
      "_default_":{
         "_all":{
            "enabled":false
         },
         "_source":{
            "enabled":true,
            "compress":true
         },
         "dynamic_templates":[
            {
               "message_template":{
                  "mapping":{
                     "index":"not_analyzed",
                     "type":"string"
                  },
                  "match":"message",
                  "match_mapping_type":"string"
               },
               "string_template":{
                  "mapping":{
                     "index":"not_analyzed",
                     "type":"string"
                  },
                  "match":"*",
                  "match_mapping_type":"string"
               }
            }
         ],
         "properties":{
            "@version":{
               "index":"not_analyzed",
               "type":"long"
            },
            "@timestamp":{
               "type":"date",
               "format":"dateOptionalTime"
            },
            "message":{
               "type":"string",
               "index":"not_analyzed",
               "dynamic":false
            }
         }
      }
   },
   "settings":{
      "index.translog.flush_threshold_ops":50000,
      "index.translog.flush_threshold_size":1073741824,
      "refresh_interval":30,
      "number_of_replicas":0,
      "number_of_shards":1
   },
   "template":"gelf-*"
}

和日志存储输出：

output {
  if [type] == "gelf" {
    elasticsearch {
      index => 'logstash-%{+YYYY.MM.dd}'
      protocol => http
      template_name => 'logstash-*'
      workers => 4
      template_overwrite => true
      template => '/etc/logstash/index-template.json'
    }
  } else {
    elasticsearch {
      index => 'logstash-%{+YYYY.MM.dd}'
      protocol => http
      template_name => 'gelf-*'
      workers => 4
      template_overwrite => true
      template => '/etc/logstash/gelf-template.json'
    }
  }
}

当收到在“message”字段中包含json的新消息时，我在ES上有映射：