lowercase elastic keywords

elastickeywordslowercase

{
  "template": "*",
  "order": 0,
  "mappings": {
    "doc": {
      "dynamic_templates": [
        {
          "strings_as_keywords": {
            "match_mapping_type": "string",
            "mapping": {
              "type": "keyword",
              "norms": false,
              "normalizer": "lowercase_normalizer"
            }
          }
        }
      ]
    }
  },
  "settings": {
    "analysis": {
      "normalizer": {
        "lowercase_normalizer": {
          "type": "custom",
          "filter": ["lowercase"]
        }
      }
    }
  }
}