[Feature]: logging request_id instead of random uuid

[cynial]

🚀 The feature, motivation and pitch

vLLM now supports the x-request-id header, as discussed in this issue: #9593.

However, during the completion process, a random ID is still being used. Could we consider using the x-request-id instead? This change would enhance our ability to trace requests more effectively.

For reference, see the current implementation here:
https://github.com/vllm-project/vllm/blob/main/vllm/entrypoints/openai/serving_completion.py#L89

request_id = f"cmpl-{random_uuid()}" :

Alternatives

No response

Additional context

No response

Before submitting a new issue...

• Make sure you already searched for relevant issues, and asked the chatbot living at the bottom right corner of the documentation page, which can answer lots of frequently asked questions.

[DarkLight1337]

This should be implemented by #10968 already.