[CI/Build] Add x86 CPU wheel release pipeline

[bigPYJ1151]

Purpose

• Add x86 CPU wheel release pipeline, for now each wheel is ~30MB
• Seperate CPU wheels (both x86 and Arm) to vllm-wheels/cpu

After #29838 merged, we only need to add a x86 CPU release pipeline.

With this change, CPU wheels can be installed via:

• Regular release version:

uv pip install vllm=="$VERSION+cpu" --extra-index-url "https://wheels.vllm.ai/$VERSION"

• Specific commits:

uv pip install vllm=="$DEV_VERSION" --extra-index-url "https://wheels.vllm.ai/$COMMIT_ID"

Test Plan

verified the scripts locally

Test Result

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Essential Elements of an Effective PR Description Checklist

• The purpose of the PR, such as "Fix some issue (link existing issues this PR will resolve)".
• The test plan, such as providing test command.
• The test results, such as pasting the results comparison before and after, or e2e results
• (Optional) The necessary documentation update, such as updating supported_models.md and examples for a new model.
• (Optional) Release notes update. If your change is user facing, please update the release notes draft in the Google Doc.

[gemini-code-assist]

Code Review

This pull request introduces a new CI pipeline for building and releasing x86 CPU wheels and correctly separates them into a vllm-wheels/cpu path in the S3 bucket. The changes are well-structured and mostly correct. However, I found a significant issue in the upload-wheels.sh script where it copies an incorrect index file for CPU wheel builds. This could lead to installation problems for users. I've provided a specific comment with a suggested fix to address this.

[gemini-code-assist]

There is an issue with this aws s3 cp command. For CPU wheel builds, $ROOT_PATH will be vllm-wheels/cpu, but the source S3 path is hardcoded to s3://vllm-wheels/nightly/index.html, which is the index for CUDA wheels. This will result in copying the CUDA wheel index into the CPU wheel commit-specific directory, leading to incorrect package resolution for users.

The source path should also use the $ROOT_PATH variable to ensure the correct index is copied for CPU builds. Additionally, it's good practice to handle the case where the nightly index might not exist yet (e.g., for the first build of a day) to prevent the step from failing.

Suggested change

	aws s3 cp "s3://vllm-wheels/nightly/index.html" "s3://$ROOT_PATH/$BUILDKITE_COMMIT/index.html"
	aws s3 cp "s3://$ROOT_PATH/nightly/index.html" "s3://$ROOT_PATH/$BUILDKITE_COMMIT/index.html" || true

[bigPYJ1151]

Hi @khluu Could you please help to check this PR? Thanks!

[khluu]

The changes on release-pipeline.yaml look good to me. Triggered a release run to verify: https://buildkite.com/vllm/release/builds/10316
For the changes to nightly index, @youkaichao can you help review it?

[bigPYJ1151]

Thanks a lot @khluu
The job is finished, and I have verified the index. Now the dev wheel can be installed via

uv pip install vllm==0.11.2.dev20+gef967c682.cpu --extra-index-url=https://wheels.vllm.ai/cpu/ef967c682b9720859f60c55bd317edddc7db928a

The CPU wheel index is valid. For CUDA there should have no change.

[youkaichao]

I'm thinking about the refactor recently. We should add directories inside s3://vllm-wheels/$BUILDKITE_COMMIT/, e.g. s3://vllm-wheels/$BUILDKITE_COMMIT/cpu/ .

[bigPYJ1151]

Updated.
Now CPU wheels and index will be uploaded to s3://vllm-wheels/$BUILDKITE_COMMIT/cpu/ and s3://vllm-wheels/$BUILDKITE_COMMIT/cpu/vllm