[source, ruby]
----
response = client.indices.create(
  index: 'my-index-000001',
  body: {
    mappings: {
      properties: {
        "@timestamp": {
          format: 'strict_date_optional_time||epoch_second',
          type: 'date'
        },
        message: {
          type: 'wildcard'
        }
      }
    }
  }
)
puts response
----
