title: append array of json logstash elasticsearch
body: <p>how can i append an array on elasticsearch with json object using logstash from csv</p>
  
  <p>exemple of csv</p>
  
  <p>a csv containt lines</p>
  
  <pre><code>id,key1,key2
  1,toto1,toto2
  1,titi1,titi2
  2,tata1,tata2
  </code></pre>
  
  <p>the result should be 2 documents</p>
  
  <pre><code>{
      "id": 1,
      [{
          "key1": "toto1",
          "key2": "toto2"
      }, {
          "key1": "titi1 ",
          "key2": "titi2"
      }]
  }
  ,{
      "id": 2,
      [{
          "key1": "tata1",
          "key2": "tata2"
      }]
  }
  </code></pre>
  
  <p>cordially</p>