feat(standalone): align agentgateway configuration with upstream GAIE PR 2905 (#1600)

* fix(standalone): rework agentgateway configuration to use derived pseudo-service

Signed-off-by: abhay1999 <abhaychaurasiya19@gmail.com>

* chore: trigger ci re-run

Signed-off-by: abhay1999 <abhaychaurasiya19@gmail.com>

* fix(standalone): update agentgateway validation error and add verification assertions

Signed-off-by: abhay1999 <abhaychaurasiya19@gmail.com>

---------

Signed-off-by: abhay1999 <abhaychaurasiya19@gmail.com>

Author: abhay1999

config/charts/README.md

@@ -32,15 +32,14 @@ helm install my-standalone-router ./config/charts/llm-d-router-standalone \
   --set router.modelServers.matchLabels.app=my-vllm-service
 ```
 
-#### Standalone with Agentgateway Proxy (Service-Backed)
-Deploys EPP with an Agentgateway proxy. This mode requires disabling the `InferencePool` resource creation (`create=false`) and routes traffic to an existing Kubernetes Service:
+#### Standalone with Agentgateway Proxy
+Deploys EPP with an Agentgateway proxy. This mode requires disabling the `InferencePool` resource creation (`create=false`) and routes traffic directly to model servers:
 
 ```bash
 helm install my-standalone-router ./config/charts/llm-d-router-standalone \
   --set router.inferencePool.create=false \
   --set router.proxy.proxyType=agentgateway \
-  --set router.proxy.agentgateway.service.name=my-model-service \
-  --set router.proxy.agentgateway.service.ports="8000"
+  --set router.modelServers.matchLabels.app=my-model-service
 ```
 
 #### Standalone with a Separate Proxy Service
@@ -538,20 +537,21 @@ Configures EPP to run with a proxy (Envoy proxy or Agentgateway proxy) that inte
 | `router.proxy.volumeMounts` | Sidecar container volume mounts. | `[]` |
 | `router.proxy.volumes` | Sidecar container volumes. | `[]` |
 | `router.proxy.configMapData` | Key-value pairs to include in a ConfigMap created for the sidecar. | `{}` |
-| `router.proxy.agentgateway.service.create` | **Agentgateway only**. Create a dedicated model Service for the Agentgateway proxy. | `true` |
-| `router.proxy.agentgateway.service.name` | **Agentgateway only**. Name of the model Service to route to. | `""` |
-| `router.proxy.agentgateway.service.namespace` | **Agentgateway only**. Namespace of the model Service. Defaults to release namespace. | `""` |
-| `router.proxy.agentgateway.service.ports` | **Agentgateway only**. Port list for the model Service (must match `modelServers.targetPorts`). | `[]` |
+#### Complete Standalone Example with Agentgateway Proxy
 
-#### Complete Proxy Sidecar Example (Agentgateway Service-Backed)
-
-To deploy EPP in standalone mode with an Agentgateway sidecar routing traffic directly to an existing model Service `my-model-service` (bypassing `InferencePool` creation):
+To deploy EPP in standalone mode with an Agentgateway sidecar routing traffic directly to model servers matching the label `app=my-model-service` (bypassing `InferencePool` creation):
 
 ```yaml
 router:
   inferencePool:
     create: false # Disable InferencePool creation
 
+  modelServers:
+    matchLabels:
+      app: "my-model-service"
+    targetPorts:
+      - number: 8000
+
   proxy:
     enabled: true
     proxyType: agentgateway
@@ -561,10 +561,4 @@ router:
         memory: 4Gi
       limits:
         memory: 8Gi
-    agentgateway:
-      service:
-        create: true # Create a Service to route client traffic to EPP
-        name: "my-model-service"
-        ports:
-          - 8000 # Intercept traffic on port 8000
 ```

config/charts/llm-d-router-standalone/templates/_validations.tpl

@@ -53,32 +53,17 @@ standalone validations
     {{- fail (printf ".Values.router.proxy.proxyType must be one of [envoy, agentgateway], got %q" $proxyType) -}}
   {{- end -}}
   {{- if eq $proxyType "agentgateway" -}}
+    {{- if hasKey $proxy "agentgateway" -}}
+      {{- fail ".Values.router.proxy.agentgateway is no longer supported; standalone agentgateway uses EPP endpoint discovery with a logical service backend" -}}
+    {{- end -}}
     {{- if ne .Values.router.inferencePool.create false -}}
       {{- fail ".Values.router.inferencePool.create=false is required when proxyType=agentgateway; standalone agentgateway currently supports only service-backed routing" -}}
     {{- end -}}
-    {{- $agentgateway := index $proxy "agentgateway" | default dict -}}
-    {{- $service := index $agentgateway "service" | default dict -}}
-    {{- $serviceName := index $service "name" | default "" -}}
-    {{- $serviceCreate := index $service "create" | default true -}}
-    {{- if hasKey $service "port" -}}
-      {{- fail ".Values.router.proxy.agentgateway.service.port has been replaced by .Values.router.proxy.agentgateway.service.ports" -}}
-    {{- end -}}
-    {{- if empty $serviceName -}}
-      {{- fail ".Values.router.proxy.agentgateway.service.name is required when proxyType=agentgateway" -}}
-    {{- end -}}
-    {{- $targetPorts := include "llm-d-router.standaloneEndpointTargetPorts" . -}}
-    {{- $servicePorts := include "llm-d-router.agentgateway.modelServicePorts" . -}}
-    {{- if ne $targetPorts $servicePorts -}}
-      {{- fail (printf ".Values.router.proxy.agentgateway.service.ports must match .Values.router.modelServers.targetPorts when proxyType=agentgateway, got service ports %q and target ports %q" $servicePorts $targetPorts) -}}
-    {{- end -}}
     {{- $listenerPort := include "llm-d-router.standaloneProxyListenerPort" . -}}
     {{- $flags := .Values.router.epp.flags | default dict -}}
     {{- if and (hasKey $flags "secure-serving") (ne (toString (index $flags "secure-serving")) "false") -}}
       {{- fail ".Values.router.epp.flags.secure-serving must be false when proxyType=agentgateway; standalone agentgateway uses plaintext gRPC to EPP over localhost" -}}
     {{- end -}}
-    {{- if $serviceCreate -}}
-      {{- $selectorLabels := include "llm-d-router.agentgateway.modelServiceSelectorLabels" . -}}
-    {{- end -}}
   {{- end -}}
 {{- end -}}
 {{- end -}}

config/charts/llm-d-router-standalone/templates/agentgateway-service.yaml

@@ -33,16 +33,7 @@ router:
       limits:
         memory: 16Gi
 
-    # Agentgateway-specific settings used by the built-in preset when
-    # proxyType=agentgateway. service.name is required.
-    agentgateway:
-      service:
-        create: true
-        name: ""
-        namespace: ""
-        # Must match inferencePool.targetPorts.
-        ports:
-          - 8000
+
 
     # Built-in standalone proxy presets. The selected preset is merged with the
     # top-level proxy.* fields below, so explicit user overrides still win.

config/charts/llm-d-router-standalone/values.yaml

@@ -269,13 +269,20 @@ Return the standalone EPP model-server target ports.
 {{- end -}}
 
 {{/*
-Return the agentgateway model Service ports.
+Return the agentgateway standalone logical backend service name.
+Derives the name from .Values.router.modelServers.matchLabels.app,
+falling back to .Release.Name if not set.
 */}}
-{{- define "llm-d-router.agentgateway.modelServicePorts" -}}
-{{- $proxyValues := .Values.router.proxy | default dict -}}
-{{- $agentgateway := index $proxyValues "agentgateway" | default dict -}}
-{{- $service := index $agentgateway "service" | default dict -}}
-{{- include "llm-d-router.normalizedPortList" (dict "path" ".Values.router.proxy.agentgateway.service.ports" "value" (index $service "ports")) -}}
+{{- define "llm-d-router.agentgateway.logicalBackendName" -}}
+{{- $appLabel := "" -}}
+{{- if and .Values.router.modelServers .Values.router.modelServers.matchLabels -}}
+  {{- $appLabel = index .Values.router.modelServers.matchLabels "app" | default "" -}}
+{{- end -}}
+{{- if not (empty $appLabel) -}}
+  {{- $appLabel -}}
+{{- else -}}
+  {{- .Release.Name -}}
+{{- end -}}
 {{- end -}}
 
 {{/*
@@ -329,30 +336,15 @@ Return the rendered proxy ConfigMap data.
 {{- toYaml $data -}}
 {{- end -}}
 
-{{/*
-Render labels from the standalone endpoint selector for the generated model Service.
-Only equality-based selectors are supported because Service selectors are a map.
-*/}}
-{{- define "llm-d-router.agentgateway.modelServiceSelectorLabels" -}}
-{{- if and .Values.router.modelServers .Values.router.modelServers.matchLabels -}}
-{{- range $key, $value := .Values.router.modelServers.matchLabels -}}
-{{- printf "%s: %s\n" ($key | quote) ($value | quote) -}}
-{{- end -}}
-{{- else -}}
-  {{- fail ".Values.modelServers.matchLabels is required when creating an agentgateway model Service" -}}
-{{- end -}}
-{{- end -}}
+
 
 {{/*
 Render the default standalone agentgateway proxy config template.
 */}}
 {{- define "llm-d-router.proxy.agentgatewayConfig" -}}
-{{- $proxyValues := .Values.router.proxy | default dict -}}
-{{- $agentgateway := index $proxyValues "agentgateway" | default dict -}}
-{{- $service := index $agentgateway "service" | default dict -}}
-{{- $serviceName := index $service "name" | default "" -}}
-{{- $serviceNamespace := index $service "namespace" | default .Release.Namespace -}}
-{{- $servicePorts := splitList "," (include "llm-d-router.agentgateway.modelServicePorts" .) -}}
+{{- $serviceName := include "llm-d-router.agentgateway.logicalBackendName" . -}}
+{{- $serviceNamespace := .Release.Namespace -}}
+{{- $servicePorts := splitList "," (include "llm-d-router.standaloneEndpointTargetPorts" .) -}}
 {{- $backendPort := index $servicePorts 0 -}}
 {{- $listenerPort := include "llm-d-router.standaloneProxyListenerPort" . | int -}}
 config: