feat: add grpc support for the huggingface text embedding inference (TEI) components

[maxdswain]

Related Issues

• fixes Support gRPC interface of TEI haystack#7522

Proposed Changes:

Add grpc support through optional grpc extras for the hugging face text embedding inference (TEI). To support this implementation, I generated a grpc client from the latest TEI protobuf. Instructions on how to regenerate the files from the protobuf have been added to the README.

This needed to be done as the existing huggingface hub inference client does not support grpc, and does not intend to.

How did you test it?

Added unit and integration tests. You need to run docker compose up -d before running the integration tests.

Notes for the reviewer

The TEI grpc API doesn't have an API where it takes a list of inputs to embed, so instead for the document embedder components, I used the EmbedStream interface. In my testing, this is faster then using multiple streams one after the other and batching requests.

I kept grpc client initialisation in the __init__ method to prevent wasted compute/time on every run or run_async call.

Checklist

• I have read the contributors guidelines and the code of conduct
• I have updated the related issue with new insights and changes
• I added unit tests and updated the docstrings
• I've used one of the conventional commit types for my PR title: fix:, feat:, build:, chore:, ci:, docs:, style:, refactor:, perf:, test:.

[github-actions]

Heads-up for maintainers

This PR is from a fork and touches integrations whose integration tests require API keys.
Those tests are skipped in CI because fork PRs don't have access to repo secrets for security reasons.

Affected integrations:

• huggingface_api

Please run the integration tests locally (hatch run test:integration inside each folder) before approving.

[socket-security]

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	pypi/​grpcio@​1.83.1

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[github-actions]

Coverage report (huggingface_api)

Click to see where and how coverage changed

File	Statements	Missing	Coverage	Coverage (new stmts)	Lines missing
integrations/huggingface_api/src/haystack_integrations/components/embedders/huggingface_api
document_embedder.py					190-191, 292, 308-309, 337, 356-357, 430, 466
sparse_document_embedder.py					150, 173, 196-197
sparse_text_embedder.py
text_embedder.py					153-154, 157-161, 249-252, 287-290
integrations/huggingface_api/src/haystack_integrations/components/embedders/huggingface_api/_grpc
tei_pb2.py					33-97
tei_pb2_grpc.py					15-16, 19, 37, 49-51, 55-65, 83, 146-148, 152-154, 158-160, 164-166, 170-172, 176-178, 182-217, 235, 262, 289, 316, 343, 370, 396-411, 423-425, 429-431, 435-437, 441-443, 447-472, 490, 517, 544, 571, 597-602, 614-616, 620-622, 626-641, 659, 686, 712-727, 739-741, 745-747, 751-753, 757-759, 763-788, 806, 833, 860, 887
Project Total

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