Kibana for various data sources

Hi.

I know currently kibana supports only elasticsearch.

BWT,
Caravel (https://github.com/airbnb/caravel) was started only for druid, but now extended to various datasources(jdbc, elasticsearch, etc..) .
Zeppelin (https://zeppelin.apache.org) support various datasource connections.

Are there or Were there any discussion about this , kibana for various datasources, far future, great imagination?

This sounds like a feature request ;). I would submit this to github (https://github.com/elastic/kibana/issues/new), with some context and added explanation to how you would like to see Kibana use other datasources.

That said, I am not sure if there were ever any. A lot of Kibana's core functionality is very tied to Elasticsearch. For example, Sense/Dev Tools to write ES queries, or the visualizations which tie into the aggregations API, etc...