Add Elasticsearch support

[JianboDM]

Does this project support elasticsearch？if not，Do you plan to support elasticsearch?

[artembilan]

The project is based mostly on the community-driver-feedback. So, if there is no demand for Elasticsearch, then there is no support in the project. But it doesn't mean that we won't add it in the future if community (you) asks for it.

We also are very open for Contribution becuase we may be busy with some other priorities, like fixing and improving already existing features.

If you already have some ideas how it can be incorporated into a project, we are very likely to accept a PR for the current 5.5 version or the next one. Or we can extract it into a extension project like we have so far for Apache Cassandra and Hazelcast: https://github.com/spring-projects/spring-integration-extensions.

I saw recently that our new Stream Applications project - Serverless Functions for Spring Integration components and similar - has gotten a contribution for Elasticsearch Consumer. So, that could be as a great starting point how to implement respective channel adapter in Spring Integration.

[migroskub]

The project is based mostly on the community-driver-feedback. So, if there is no demand for Elasticsearch, then there is no support for the project.

@artembilan But there is. And so for all of the other requested channel adapters. This project for some reason doesn't add support for the most common and standard databases and technologies in the industry, even though it is being developed for years. I don't expect special functionalities or something. Just bulk-based channel adapters for most of the databases (addition of a channel adapter won't take more than 1-2 days for a developer who knows this library well).

[artembilan]

Sure, @migroskub !

We are just short-handed over here in our team for the project.
Plus I'm not familiar with Elasticsearch to jump into an implementation immediately.
Therefore I'm asking for a contribution which I'll gladly review quickly and so on.

Thanks for understanding!

[migroskub]

@artembilan I understand and I’ll try to find the right time for contribution of some channel adapters. Anyway, writing to ES with Spring is super easy. Basic familiarity with the ReactiveElasticsearchClient should be enough.

[rolkhas2]

I don't understand why doesn't this channel adapter documented here. I'm struggling with finding a way of using it.

[artembilan]

@rolkhas2 ,

there is just not Elasticsearch support in this project yet, therefore no docs on the matter.
This issue is exactly about implementing those and document them properly.