Support New Origin Type: Elasticsearch

[jranson]

Dependent on #9 completion

[softwareklinic]

Thank you - will keep an eye on this thread.,.,.

[mzagar]

Hi!

Any plans on adding support for elasticsearch?

Also, is there any special reason why it is not supported (or it is hard to do it) or is it a matter of doing the same thing as for other backends?

[houyuwushang]

@jranson I took a fresh look at this against current main.

What I see so far:

• the prerequisite origin-interface work in Implement Interfacing to support varying Upstream Origin Types #9 is completed;
• I do not see an existing Elasticsearch provider or active PR;
• reverseproxycache can already proxy/cache selected Elasticsearch HTTP endpoints when configured explicitly, including POST/JSON cache-key fields, but that is not the same as first-class Elasticsearch time-series acceleration.

From #341 and #167, my read is that the unresolved part is likely Grafana-style Elasticsearch queries where Trickster would need to understand the JSON query body, derive a stable cache key with the time range normalized, split/set the requested time range, and model date-histogram-like responses safely.

Before I start implementation work, would you prefer this to be scoped as:

1. documentation/config examples for using rpc with Elasticsearch where object caching is sufficient,
2. a minimal first-class Elasticsearch provider targeting Grafana _search / _msearch time-series date histogram queries, including configurable timestamp field support, or
3. something else entirely?

If option 2 is still the desired direction, I can work up a narrow design and first PR rather than trying to land the whole provider in one large change.

[houyuwushang]

I opened #1052 for this.

Scope in this first provider implementation:

• adds provider: elasticsearch and registers it as a time-series backend;
• supports DPC acceleration for _search / _msearch date histogram queries with a configurable timestamp field, defaulting to @timestamp;
• normalizes range values in the cache key and rewrites range / extended_bounds when fetching missing extents;
• falls back conservatively to Object Proxy Cache for unsupported search shapes and proxies write-oriented methods without caching;
• documents the supported shape and elasticsearch.timestamp_field option.

Local validation included focused Elasticsearch/provider tests, lint for the touched packages, config validation for examples/conf/example.full.yaml, compile-only go test -run '^$' ./..., and git diff --check.