Incorrect configuration for mapping template with generic property

[lakario]

NEST/Elasticsearch.Net version:
5.6.0

Elasticsearch version:
5.6.6

Description of the problem including expected versus actual behavior:

The NEST API for specifying an index template with a mapping template which has a generic property exposes a method .Index(FieldIndexOption) rather than .Index(bool), as is the case with other type descriptors. The options exposed in the enum FieldIndexOption only apply to the legacy string type and in 5.x, the value of "index" must be either true or false.

https://www.elastic.co/guide/en/elasticsearch/reference/5.5/mapping-index.html

Consider the following example which creates such an invalid specification:

var response = _client.PutIndexTemplate(templateName, desc => desc
	.Template("index_template*")
	.Settings(settings => settings
		.NumberOfShards(1)
		.NumberOfReplicas(1)
	.Mappings(mappings => mappings
		.Map<object>("_default_", s => s
			.AllField(all => all
				.Enabled(false))
			.DynamicTemplates(dynamicTemplates => dynamicTemplates
				.DynamicTemplate("default_template", defaultTemplate => defaultTemplate
					.Match("*")
					.Mapping(mapping => mapping
						.Generic(g => g
							.Type("{dynamic_type}")
							// this is not valid in ES5
							.Index(FieldIndexOption.NotAnalyzed) 
							.DocValues(true)
						)
					)
				)
			)
			.Properties(properties => properties
				.Date(date => date.Name("timestamp"))
				.Date(date => date.Name("expiry"))
			)
		)
	)
);

[lakario]

Looking through the sources on master, it would seem that the issue still exists in the latest versions of the library. Reviewing the solution, there are 14 outstanding usages of the enum FieldIndexOption. Half of the references are in the obsolete StringAttribute and StringProperty types, and the rest are in GenericProperty.

https://github.com/elastic/elasticsearch-net/blob/master/src/Nest/Mapping/Types/Specialized/Generic/GenericProperty.cs

[russcam]

Thanks for reporting @lakario

[russcam]

Will be fixed in the next release of 5.x and 6.x. In these versions, a new property has been introduced, Indexed, of type bool?, that can be used to set the "index" value for a generic property.

Sadly, we can't change the type of the property Index in 5.x or 6.x as it would break binary compatibility within a major version. In master however, the change has been made and FieldIndexOption removed.

Thanks again for opening!