How to use logstash to index file with suggester mapping

Hello,

I am new to Elastic search , and I want to implement auto complete search functionality by indexing data from JSON file , however all the samples I can find for "completion" suggester is using curl or developer tool to create index and define required mapping and insert some records for defined index (documents), but nothing to insert data from file which probably as I understand would need logstash , so how I can define my logstash configuration with the right mapping , for example something like the following mapping :

"mappings": {
    "properties": {
      "name":{
        "type":"keyword"
      },
      "suggest":{
        "type": "completion"
      }
    }
  }

Is there any complete sample for this purpose , Or this procedure is not correct ?