Elastic reindex with array field changes

elastic-reindex-modify-fields

POST _reindex
{
  "source": {
    "index": "events-2022-09-v2"
  },
  "dest": {
    "index": "events-2022-09-v3"
  },
  "script": {
    "source": """
      if(ctx._source.mitreAttckList instanceof List && ctx._source.mitreAttckList.size()>0) {
          for (int i=0; i<ctx._source.mitreAttckList.size(); i++) {
            ctx._source.mitreAttckList[i].technique = ctx._source.mitreAttckList[i].name;
            ctx._source.mitreAttckList[i].tactic = ctx._source.mitreAttckList[i].categories;
            ctx._source.mitreAttckList[i].remove("name");
            ctx._source.mitreAttckList[i].remove("categories");
          }
      }
        """
  }
}