feat: add plain Service baseline without Gateway or routing proxy

[WenjiaoYue]

Summary

Add a plain Kubernetes Service baseline for ModelService benchmarks through the new gateway.className: none mode.

This provides a direct benchmark path:

benchmark harness -> ClusterIP Service -> decode vLLM

The mode does not deploy or include the following components in the request path:

• Kubernetes Gateway
• HTTPRoute
• EPP
• Envoy
• llm-d router
• ModelService routing proxy

Fixes #1650.

Changes

• Add none as a supported Gateway class.
• Render a benchmark-managed ClusterIP Service selecting ModelService decode pods.
• Disable the ModelService per-pod routing proxy in direct mode.
• Make vLLM listen directly on routing.servicePort.
• Retarget custom decode commands from $VLLM_METRICS_PORT to $VLLM_INFERENCE_PORT.
• Skip Gateway API CRDs, inference extension CRDs, Gateway provider, router, and HTTPRoute deployment.
• Add direct Service endpoint discovery for:
  • standup smoketests
  • inference tests
  • benchmark runs
  • standalone smoketest workflows
• Clean up the direct Service during teardown.
• Reject incompatible direct-mode configurations:
  • P/D disaggregation with prefill replicas
  • shared HTTPRoute mode
  • configurations without a decode replica
• Update CLI help and documentation.

Usage

gateway:
  className: none

[Copilot]

Pull request overview

Adds a new gateway.className: none “direct Service” baseline lane for ModelService benchmarking, allowing the harness to hit decode vLLM through a plain ClusterIP Service with no Gateway/API resources and no routing proxy in the request path.

Changes:

• Adds none as a supported gateway class and normalizes direct mode by disabling the per-pod routing proxy and retargeting vLLM custom commands to $VLLM_INFERENCE_PORT.
• Renders/applies a benchmark-managed *-direct ClusterIP Service and updates endpoint discovery (smoketests, inference tests, benchmark runs) to use it.
• Skips router/gateway deployment and gateway prerequisites (Gateway API CRDs/provider/HTTPRoute/infra chart) when in direct mode, plus updates docs/CLI help and adds tests.

Reviewed changes

Copilot reviewed 23 out of 23 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tests/test_direct_service_mode.py	Adds unit/integration-style coverage for direct mode normalization, constraints, rendering, and endpoint discovery.
README.md	Updates CLI help text to document --gateway-class none behavior.
llmdbenchmark/utilities/endpoint.py	Adds find_direct_modelservice_endpoint() for discovering the plain Service endpoint.
llmdbenchmark/teardown/steps/step_03_delete_resources.py	Expands teardown pattern matching to include -direct resources.
llmdbenchmark/standup/steps/step_11_inference_test.py	Uses direct Service endpoint discovery for gateway.className=none.
llmdbenchmark/standup/steps/step_10_smoketest.py	Uses direct Service endpoint discovery for gateway.className=none.
llmdbenchmark/standup/steps/step_09_deploy_modelservice.py	Applies the direct Service manifest and skips router-related waits/labeling in direct mode.
llmdbenchmark/standup/steps/step_08_deploy_router.py	Skips router deployment step entirely for direct mode.
llmdbenchmark/standup/steps/step_02_admin_prerequisites.py	Skips Gateway API/extension/provider prerequisites for direct mode.
llmdbenchmark/smoketests/base.py	Adds direct Service endpoint discovery for smoketests.
llmdbenchmark/run/steps/step_03_detect_endpoint.py	Adds direct Service endpoint discovery for benchmark runs.
llmdbenchmark/parser/render_plans.py	Adds none gateway class support, direct-mode normalization, and direct-mode constraint validation.
llmdbenchmark/parser/README.md	Documents gateway.className: none behavior and intent.
llmdbenchmark/interface/standup.py	Updates CLI help to include none as a supported gateway class.
llmdbenchmark/interface/run.py	Updates CLI help to include none as a supported gateway class.
llmdbenchmark/interface/plan.py	Updates CLI help to include none as a supported gateway class.
llmdbenchmark/interface/experiment.py	Updates CLI help to include none as a supported gateway class.
docs/standup.md	Documents the new none gateway class lane and constraints.
config/templates/values/defaults.yaml	Documents gateway.className: none in defaults commentary.
config/templates/jinja/13a_modelservice-direct-service.yaml.j2	Adds a new template rendering the plain ClusterIP Service for direct mode.
config/templates/jinja/11_infra.yaml.j2	Skips infra rendering for direct mode (and epponly).
config/templates/jinja/10_helmfile-main.yaml.j2	Skips infra/router releases and repo in direct mode; adjusts ms needs: accordingly.
config/templates/jinja/08_httproute.yaml.j2	Skips HTTPRoute rendering in direct mode.

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[Vezio]

@WenjiaoYue is this change intended?