Keyword type to lowercase

Elastic Stack Elasticsearch
1

Normalizer for Keyword datatype is Experimental currently.

https://www.elastic.co/guide/en/elasticsearch/reference/current/keyword.html#keyword-params

Is there another way to lowercasing value of keyword field?

this is mapping

properties : {
  "country" : {
    "type":"keyword"
  }
}

Add documents

POST  {
  "country":"US"
}
POST  {
  "country":"us"
}

Now, want to search both US and us.
this expected to return two document above.

GET
search?q=country:us

How can I do that without using experimental feature?

2

You can use ingest node and lowercase your field at index time.