fix: two-layer gzip decompression for all inbound routes

[SudipSinha]

Summary

Fixes gzip decompression for KServe inference payloads across all three inbound paths:

• /data/upload (FastAPI)
• /consumer/kserve/v2 (FastAPI)
• CloudEvent consumer (POST /) (FastAPI)

Mirrors the two-layer fix from Java TrustyAI service: trustyai-explainability/trustyai-explainability#707

Problem

TrustyAI fails to parse gzip-compressed inference payloads from KServe logger sidecar with error:

JSONDecodeError: Expecting value: line 1 column 1 (char 0)

The gzip magic bytes 0x1F 0x8B are being parsed as JSON. The initial gzip middleware was scoped only to /data/upload, leaving two paths uncovered:

1. /consumer/kserve/v2 — FastAPI endpoint but outside middleware scope
2. CloudEvent consumer (POST /) — Knative Eventing bypasses standard HTTP middleware

Design Philosophy

HTTP Content-Encoding is a transport-layer concern, not an application-layer concern. Handling it per-endpoint creates coverage gaps — every new endpoint becomes vulnerable by default until someone remembers to add decompression.

The correct approach is layered defense:

1. Transport layer first: Enable middleware-level decompression to handle all HTTP requests before they reach endpoint handlers

2. Application layer fallback: When a framework bypasses the transport layer (Knative Eventing strips Content-Encoding header but leaves body gzipped), add endpoint-specific decompression as a safety net

This ensures:

• New endpoints are secure by default (middleware handles them)
• Framework-specific edge cases are covered (application layer catches what middleware misses)
• No per-endpoint boilerplate

Solution

Two-layer fix:

1. Middleware layer (FastAPI endpoints):

   • Change GzipRequestMiddleware.DEFAULT_PATHS from ("/data/upload",) to ("*",)
   • All routes now get automatic gzip decompression

2. Application layer (CloudEvent endpoints):

   • Add decompress_if_gzip() utility in src/endpoints/consumer/gzip_utils.py
   • Magic byte detection (0x1F 0x8B)
   • 100MB decompression bomb guard
   • Graceful fallback on malformed payloads
   • Called from CloudEvent consumer when Content-Encoding header is missing

Changes

File	Change
src/middleware/gzip_middleware.py	Changed DEFAULT_PATHS to ("*",)
src/endpoints/consumer/gzip_utils.py	+59 lines (gzip detection + bomb guard)
src/endpoints/consumer/consumer_endpoint.py	+30 lines (CloudEvent gzip handling)
src/endpoints/data/data_upload.py	Removed explicit path from middleware call
tests/middleware/test_gzip_middleware_unit.py	+45 lines (parametrized route tests)
tests/endpoints/consumer/test_cloud_event_gzip.py	+92 lines (4 CloudEvent tests)

Net: +245 / -24 lines

Test Plan

• uv run pytest tests/middleware/test_gzip_middleware_unit.py -v - All tests pass
• uv run pytest tests/endpoints/consumer/test_cloud_event_gzip.py -v - All tests pass
• Verify middleware decompresses on all routes (/data/upload, /consumer/kserve/v2, /)
• Verify CloudEvent endpoint handles gzip body without Content-Encoding header
• Cluster validation

Related

• Jira (Python): RHOAIENG-67124 — Python service gzip fix
• Java implementation: fix(RHOAIENG-66317): Fix gzip decompression for all inbound endpoints trustyai-explainability#707
• Jira (Java): RHOAIENG-66317 — Original Java service issue
• Epic: RHAISTRAT-130
• Related: RHOAIENG-60518 — KServe logger integration
• Related: RHOAIENG-52393 — Monitoring infrastructure

---

🤖 Generated with Claude Code

[coderabbitai]

Warning

Review limit reached

@SudipSinha, you've reached your PR review limit, so we couldn't start this review.

Next review available in: 22 minutes

Enable usage-based reviews in Billing to review now. Otherwise, wait until the next included review is available.
You're only billed for reviews past your plan's rate limits ($0.25/file).

How can I continue?

After more reviews become available, a review can be triggered using the @coderabbitai review command as a PR comment. Alternatively, push new commits to this PR.

To avoid repeated limits, reduce automatic review volume by pausing incremental auto-reviews earlier, using label-based review opt-in, excluding WIP or generated PR titles, or requesting reviews manually when the PR is ready. If your team needs uninterrupted high-volume reviews, an organization admin can enable usage-based reviews.

How do review limits work?

CodeRabbit enforces per-developer PR review limits for each organization. Most developers receive the normal plan review availability.

For paid Pro and Pro+ PR reviews, CodeRabbit uses adaptive limits for sustained high-volume activity. When a developer's recent PR review activity reaches the 95th percentile or higher among CodeRabbit users, additional reviews become available more gradually as earlier reviews age out of the rolling window.

Please refer docs for additional details.

Review details

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: ff8bfbd7-60cb-41ba-aa75-0349fc1e51e9

📥 Commits

Reviewing files that changed from the base of the PR and between 483b8fa and 6afc88e.

📒 Files selected for processing (6)

• src/trustyai_service/endpoints/consumer/consumer_endpoint.py
• src/trustyai_service/endpoints/consumer/gzip_utils.py
• src/trustyai_service/endpoints/data/data_upload.py
• src/trustyai_service/middleware/gzip_middleware.py
• tests/endpoints/consumer/test_cloud_event_gzip.py
• tests/middleware/test_gzip_middleware_unit.py

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/gzip-middleware-all-paths

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[github-actions]

PR image build and manifest generation completed successfully!

📦 PR image: quay.io/trustyai/trustyai-service-python-ci:6afc88e5eea07d0840aba425519422748d170d79

🗂️ CI manifests

devFlags:
  manifests:
    - contextDir: config
      sourcePath: ''
      uri: https://api.github.com/repos/trustyai-explainability/trustyai-service-operator-ci/tarball/service-python-6afc88e5eea07d0840aba425519422748d170d79

[RobGeada]

are these comments not a useful thing to keep?

[RobGeada]

ibid

[RobGeada]

ibid