fix(server): use asyncio.sleep instead of time.sleep in sandbox create

[skyler0513]

Summary

_wait_for_sandbox_ready in kubernetes_service.py used time.sleep() inside an async def call chain, which blocks the entire asyncio event loop thread during each poll interval.

With a 3-pod pool and 3 concurrent requests, each request was ~2s slower than a single request because the polls were effectively serialized.

With 4 concurrent requests (exceeding pool size), all 4 timed out — the 4th request's blocking sleep held the event loop for the entire timeout duration, preventing responses to the first 3 from being sent.

Fix: make _wait_for_sandbox_ready and create_sandbox async def, replace time.sleep with await asyncio.sleep, and add the missing await in lifecycle.py.

Testing

• Unit tests
• e2e / manual verification (4 concurrent requests against a 3-pod pool: requests 1–3 complete in ~3s, request 4 completes in ~6s after a pod is released)

Breaking Changes

• None

Checklist

• Linked Issue or clearly described motivation
• Added/updated docs (if needed)
• Added/updated tests (if needed)
• Security impact considered
• Backward compatibility considered

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 7c529d9f1c

ℹ️ About Codex in GitHub

Codex has been enabled to automatically review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

When you sign up for Codex through ChatGPT, Codex can also answer questions or update the PR, like "@codex address that feedback".

[Copilot]

Pull request overview

This PR removes event-loop blocking during Kubernetes sandbox creation by making readiness polling fully asynchronous and awaiting sandbox creation from the API layer.

Changes:

• Convert create_sandbox / _wait_for_sandbox_ready to async def and replace time.sleep() with await asyncio.sleep().
• Update the lifecycle API endpoint to await sandbox creation.
• Update unit tests to await async service methods.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

File	Description
server/src/services/k8s/kubernetes_service.py	Makes sandbox readiness polling non-blocking via asyncio.sleep and awaits readiness in create_sandbox.
server/src/services/sandbox_service.py	Changes the abstract create_sandbox contract to async.
server/src/api/lifecycle.py	Awaits the now-async sandbox_service.create_sandbox.
server/tests/k8s/test_kubernetes_service.py	Updates tests to run under asyncio and await service methods.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
1 out of 2 committers have signed the CLA.

✅ Pangjiping
❌ skyler.su

---

skyler.su seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[Copilot]

Pull request overview

This PR addresses event-loop blocking during Kubernetes sandbox creation by making the sandbox creation path fully async and replacing blocking sleeps with non-blocking asyncio.sleep.

Changes:

• Convert SandboxService.create_sandbox (and implementations) to async def and update call sites to await it.
• Update Kubernetes sandbox readiness polling to use await asyncio.sleep(...) during polling.
• Update affected unit tests to be async (pytest.mark.asyncio) and to use AsyncMock where needed.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
server/src/services/k8s/kubernetes_service.py	Makes _wait_for_sandbox_ready / create_sandbox async and switches polling sleep to await asyncio.sleep.
server/src/services/sandbox_service.py	Updates the abstract service interface to require an async create_sandbox.
server/src/services/docker.py	Updates Docker service create_sandbox signature to async to match the interface.
server/src/api/lifecycle.py	Fixes the endpoint to await sandbox_service.create_sandbox(...).
server/tests/k8s/test_kubernetes_service.py	Converts tests to async and updates calls to await.
server/tests/test_docker_service.py	Converts relevant tests to async and awaits create_sandbox; updates mocking to AsyncMock where appropriate.
server/tests/test_routes_create_delete.py	Updates route test stub service to provide an async create_sandbox.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Pangjiping]

Great fix! Please sign the CLA and run uv run ruff check --fix under server dir to fix linter error. 😊😊

[Pangjiping]

LGTM. I will fix unit test error.