Allow not to extend keep alive of Point in Time

[pongraczgabor87]

Which version of Elastic are you using?

[x] elastic.v7 (for Elasticsearch 7.x)
[ ] elastic.v6 (for Elasticsearch 6.x)
[ ] elastic.v5 (for Elasticsearch 5.x)
[ ] elastic.v3 (for Elasticsearch 2.x)
[ ] elastic.v2 (for Elasticsearch 1.x)

Please describe the expected behavior

Based on the elasticsearch documentation during the _search the keep_alive parameter is optional, it's only needed if you would like to extend the TTL of the given point in time.

Please describe the actual behavior

• I couldn't leave out the keep_alive from the request.
• If I try to set it to empty string I receive an error from elasticsearch: Error 400 (Bad Request): [1:762] [pit] failed to parse field [keep_alive] [type=x_content_parse_exception].
• If I try to set it to 0, something strange happens in the elasticsearch, the PIT is not removed as expected.

Any steps to reproduce the behavior?

searchResult, err := client.Search().
		// Index(testIndexName). // <-- you may not use indices with PointInTime!
		Query(NewMatchAllQuery()).
		PointInTime(NewPointInTime(pitResp.Id, "")). // or "0m", "0s", etc...
		Size(100).
		Pretty(true).
		Do(context.TODO())

Proposal

Make keep_alive optional.

[olivere]

Yep. Fixed in 7.0.28. Thanks.