Add e2e tests for Quickwit sink connector

[hubcio]

The Quickwit sink connector lacks integration tests. Follow the Postgres sink pattern from #2579.

What needs testing

• Basic indexing: messages in Iggy → documents in Quickwit
• Index creation from YAML config
• Bulk ingest behavior
• Error handling for invalid payloads

Implementation notes

• Quickwit has an official Docker image for testing
• The connector uses HTTP API directly (no SDK), so we can verify with direct API calls
• Index config is YAML-based, test with a simple schema

Files to reference

• core/integration/tests/connectors/postgres/postgres_sink.rs
• core/connectors/sinks/quickwit_sink/src/lib.rs

Acceptance criteria

• Basic e2e test with JSON documents
• Tests validate data actually lands in Quickwit
• CI-compatible (container setup)

[siphonite]

Hi

I’d love to take this issue and follow the Postgres sink pattern as suggested.
If there’s anything specific I should be careful about for Quickwit tests, please let me know

[hubcio]

@siphonite assigned, so far nothing specific comes to my mind.

[siphonite]

Hi @hubcio

I have implemented most of the Quickwit sink e2e test but I’m currently blocked by WSL + Docker instability on my local machine (limited resources cause repeated test/runtime failures even though the logic is in place).

I didn’t want to leave half-baked work, so I’m pausing here for now. If someone else wants to pick this up and finish/verify it on a more stable Linux setup, that would be great. Happy to provide context or help review.

Thanks:)

[hubcio]

sure - can you raise PR? we can validate stability using github CI.

[siphonite]

Sure. I will raise a PR in sometime.

[JoshuaXOng]

I can try this one out.

[hubcio]

Sure @JoshuaXOng, assigned.