fix: add --api-key support and authentication warning to gRPC server

[ChristinaSaikoy]

The HTTP server has AuthenticationMiddleware for API key validation, but the gRPC server had no authentication mechanism whatsoever. Add --api-key CLI argument and a warning log when authentication is not configured, bringing the gRPC server in line with the HTTP server's security posture.

CWE-304: Missing Critical Step in Authentication

Purpose

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Test Result

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[gemini-code-assist]

Code Review

This pull request introduces an --api-key CLI argument to the gRPC server and adds a warning message when the server is started without authentication. The reviewer pointed out that the implementation is currently incomplete as it lacks a gRPC interceptor to enforce authentication and does not fall back to the VLLM_API_KEY environment variable, providing a code suggestion to address the latter.

[gemini-code-assist]

The authentication logic is incomplete and inconsistent with the HTTP server's security posture.

1. Missing Enforcement: While the CLI argument and warning are added, there is no gRPC interceptor implemented to actually validate the API keys against incoming requests. The server remains accessible to anyone even if keys are provided.
2. Missing Fallback: The check should fall back to envs.VLLM_API_KEY if --api-key is not specified, matching the behavior in vllm/entrypoints/openai/api_server.py.

Suggested change

	if not args.api_key:
	logger.warning(
	"No --api-key set. gRPC server is running without authentication. "
	"Anyone who can reach this port (%s) has full access to the "
	"vLLM engine.",
	address,
	)
	api_keys = [k for k in (args.api_key or [envs.VLLM_API_KEY]) if k]
	if not api_keys:
	logger.warning(
	"No --api-key set or VLLM_API_KEY env var found. gRPC server is "
	"running without authentication. Anyone who can reach this "
	"port (%s) has full access to the vLLM engine.",
	address,
	)

[ChristinaSaikoy]

Hi @simon-mo, hope you're doing well!

The gRPC authentication interceptor and the VLLM_API_KEY fallback are all in place, and everything should be ready for review. Would you mind adding the ready label when you get a chance so the CI checks can run?

Thanks a lot for your time!

[github-actions]

This pull request has been automatically marked as stale because it has not had any activity within 90 days. It will be automatically closed if no further activity occurs within 30 days. Leave a comment if you feel this pull request should remain open. Thank you!

[github-actions]

This pull request has been automatically closed due to inactivity. Please feel free to reopen if you intend to continue working on it. Thank you!