add validation for route cache action

Author: TheRealSibasishBehera

api/v1alpha1/ext_proc_types.go

@@ -49,13 +49,12 @@ type ExtProcProvider struct {
 
 	// RouteCacheAction describes the route cache action to be taken when an
 	// external processor response is received in response to request headers.
-	// The default behavior is "FromResponse" which will only clear the route cache when
-	// an external processing response has the clear_route_cache field set.
-	// Envoy: Supported
+	// If not specified, the Envoy default value of "FromResponse" will be used, which only clears
+	// the route cache when an external processing response has the clear_route_cache field set.
+	// Envoy: Supported (default: FromResponse)
 	// Agentgateway: Not Supported (ignored)
 	// +optional
 	// +kubebuilder:validation:Enum=FromResponse;Clear;Retain
-	// +kubebuilder:default=FromResponse
 	RouteCacheAction ExtProcRouteCacheAction `json:"routeCacheAction,omitempty"`
 
 	// MetadataOptions allows configuring metadata namespaces to forwarded or received from the external

install/helm/kgateway-crds/templates/gateway.kgateway.dev_gatewayextensions.yaml

@@ -548,13 +548,12 @@ spec:
                         type: string
                     type: object
                   routeCacheAction:
-                    default: FromResponse
                     description: |-
                       RouteCacheAction describes the route cache action to be taken when an
                       external processor response is received in response to request headers.
-                      The default behavior is "FromResponse" which will only clear the route cache when
-                      an external processing response has the clear_route_cache field set.
-                      Envoy: Supported
+                      If not specified, the Envoy default value of "FromResponse" will be used, which only clears
+                      the route cache when an external processing response has the clear_route_cache field set.
+                      Envoy: Supported (default: FromResponse)
                       Agentgateway: Not Supported (ignored)
                     enum:
                     - FromResponse

pkg/agentgateway/plugins/traffic_plugin.go

@@ -973,8 +973,9 @@ func validateExtProcProvider(provider *v1alpha1.ExtProcProvider) error {
 		errs = append(errs, fmt.Errorf("statPrefix field in ExtProcProvider is not supported for agentgateway"))
 	}
 
-	// TODO: RouteCacheAction has a kubebuilder default so we don't validate it here
-	// to avoid false positives when the default is automatically applied.
+	if provider.RouteCacheAction != "" {
+		errs = append(errs, fmt.Errorf("routeCacheAction field in ExtProcProvider is not supported for agentgateway"))
+	}
 
 	if provider.MetadataOptions != nil {
 		errs = append(errs, fmt.Errorf("metadataOptions field in ExtProcProvider is not supported for agentgateway"))