chore(ci): optimize Docker setup for ephemeral K8s pod runners

[key4ng]

Description

Problem

The first docker run on a fresh DinD pod is slow due to Docker daemon cold start. K8s pod runners pull Docker images (Oracle XE, Brave MCP) from Docker Hub on every CI run because pods are ephemeral and have no persistent image cache. Additionally, Docker container cleanup steps cause unnecessary delays since the pod is destroyed after job completion.

Solution

• Pull image from docker hub is actually not the bottleneck. Using cache and reload might also slower than directly pull, so didn't adopt the cache solution
• Remove Docker container cleanup steps as K8s pod is destroyed after job completion
• Add Docker daemon warmup step to avoid cold-start penalty on first container
• Switch Oracle image to 21-slim-faststart for faster DB startup

Changes

• Remove Cleanup Brave MCP Server and Cleanup Oracle Database steps
• Add docker info warmup step (conditional on setup_oracle || setup_brave)
• Switch gvenzl/oracle-xe:21-slim → gvenzl/oracle-xe:21-slim-faststart

Test Plan

Checklist

• cargo +nightly fmt passes
• cargo clippy --all-targets --all-features -- -D warnings passes
• (Optional) Documentation updated

Summary by CodeRabbit

Release Notes

• Chores
  • Optimized CI/CD workflow for end-to-end testing pipeline.
  • Improved Docker resource management by adding container cleanup.
  • Enhanced Oracle Database initialization with faster startup configuration.
  • Streamlined artifact handling during test preparation stages.

[gemini-code-assist]

Note

Gemini is unable to generate a summary for this pull request due to the file types involved not being currently supported.

[coderabbitai]

📝 Walkthrough

Walkthrough

Modifies the .github/workflows/pr-test-rust.yml CI workflow to optimize the gateway-e2e test setup by introducing a Docker daemon warmth-up step, consolidating wheel artifact download and installation earlier in the job flow, updating Oracle Database container startup parameters, and removing post-test cleanup steps.

Changes

Cohort / File(s)	Summary
CI Workflow Configuration .github/workflows/pr-test-rust.yml	Reorganizes gateway-e2e test setup: adds Docker daemon warmth-up, moves wheel artifact download/install earlier in job, updates Oracle Database container invocation with --rm flag and faststart tag variant, installs e2e dependencies from wheel, and removes post-test cleanup steps for Brave MCP Server and Oracle Database.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• fix(ci): add reusable composite actions for backend setup #319: Modifies the same workflow file to refactor how inference backends and wheel artifacts are installed in CI, consolidating setup steps via composite actions; related through shared goal of streamlining artifact handling in the test pipeline.

Suggested reviewers

• XinyueZhang369

Poem

🐰 A workflow refinement with Docker warmth so bright,
Wheels installed early, artifacts staged just right,
Oracle fastens, cleanup recedes,
The pipeline hops swiftly to meet all its needs! ✨

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely summarizes the main change: optimizing Docker setup for ephemeral K8s pod runners, which matches the PR's primary objective of improving CI performance.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch fix-docker-pull

---

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