Is your feature request related to a problem?

The Validator class used for the validator field in Setting is not Writeable.

What solution would you like?

Create a new class in the Hello World Extension package similar to ExampleCustomSettingsConfig in the OpenSearch example-plugins:custom-settings module. Demonstrate a validated string setting (see example in the custom setting plugin) that does not allow the word "forbidden".

In the Setting class, add a RegexValidator class implementing Validator<T> and Writeable that throws an exception if the String (regular expression) matches the input value.

• make the word that's forbidden a regex in a String field you set in the constructor, and that gets written.

Make sure the getSettings() extension point sends this setting to OpenSearch.

Update WriteableSetting to write the validator.