agentgateway: add extproc translation in traffic policy plugin

api/v1alpha1/ext_proc_types.go

@@ -17,39 +17,50 @@ type ExtProcProvider struct {
 	FailOpen bool `json:"failOpen,omitempty"`
 
 	// ProcessingMode defines how the filter should interact with the request/response streams.
+	// Envoy: Supported
+	// Agentgateway: Not Supported (ignored)
 	// +optional
 	ProcessingMode *ProcessingMode `json:"processingMode,omitempty"`
 
 	// MessageTimeout is the timeout for each message sent to the external processing server.
+	// Envoy: Supported
+	// Agentgateway: Not Supported (ignored)
 	// +optional
 	// +kubebuilder:validation:XValidation:rule="matches(self, '^([0-9]{1,5}(h|m|s|ms)){1,4}$')",message="invalid timeout value"
 	// +kubebuilder:validation:XValidation:rule="duration(self) >= duration('1ms')",message="timeout must be at least 1ms."
 	MessageTimeout *metav1.Duration `json:"messageTimeout,omitempty"`
 
 	// MaxMessageTimeout specifies the upper bound of override_message_timeout that may be sent from the external processing server.
 	// The default value 0, which effectively disables the override_message_timeout API.
+	// Envoy: Supported
+	// Agentgateway: Not Supported (ignored)
 	// +optional
 	// +kubebuilder:validation:XValidation:rule="matches(self, '^([0-9]{1,5}(h|m|s|ms)){1,4}$')",message="invalid timeout value"
 	// +kubebuilder:validation:XValidation:rule="duration(self) >= duration('1ms')",message="timeout must be at least 1ms."
 	MaxMessageTimeout *metav1.Duration `json:"maxMessageTimeout,omitempty"`
 
 	// StatPrefix is an optional prefix to include when emitting stats from the extproc filter,
 	// enabling different instances of the filter to have unique stats.
+	// Envoy: Supported
+	// Agentgateway: Not Supported (ignored)
 	// +optional
 	// +kubebuilder:validation:MinLength=1
 	StatPrefix *string `json:"statPrefix,omitempty"`
 
 	// 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.
+	// 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
 	// processing server.
+	// Envoy: Supported
+	// Agentgateway: Not Supported (ignored)
 	// +optional
 	MetadataOptions *MetadataOptions `json:"metadataOptions,omitempty"`
 }
@@ -77,11 +88,15 @@ type ExtProcPolicy struct {
 	ExtensionRef *NamespacedObjectReference `json:"extensionRef,omitempty"`
 
 	// ProcessingMode defines how the filter should interact with the request/response streams
+	// Envoy: Supported
+	// Agentgateway: Not Supported (ignored)
 	// +optional
 	ProcessingMode *ProcessingMode `json:"processingMode,omitempty"`
 
 	// Disable all external processing filters.
 	// Can be used to disable external processing policies applied at a higher level in the config hierarchy.
+	// Envoy: Supported
+	// Agentgateway: Not Supported (ignored)
 	// +optional
 	Disable *PolicyDisable `json:"disable,omitempty"`
 }

go.mod

@@ -4,7 +4,7 @@ go 1.25.3
 
 require (
 	// Also update AgentgatewayDefaultTag in pkg/deployer/wellknown.go and test/deployer/testdata/*
-	github.com/agentgateway/agentgateway v0.10.3
+	github.com/agentgateway/agentgateway v0.10.4
 	github.com/avast/retry-go/v4 v4.3.3
 	github.com/cncf/xds/go v0.0.0-20250501225837-2ac532fd4443
 	github.com/envoyproxy/go-control-plane v0.13.5-0.20251015221300-4138018a492b

go.sum

@@ -194,8 +194,8 @@ github.com/ProtonMail/gopenpgp/v2 v2.7.1 h1:Awsg7MPc2gD3I7IFac2qE3Gdls0lZW8SzrFZ
 github.com/ProtonMail/gopenpgp/v2 v2.7.1/go.mod h1:/BU5gfAVwqyd8EfC3Eu7zmuhwYQpKs+cGD8M//iiaxs=
 github.com/acarl005/stripansi v0.0.0-20180116102854-5a71ef0e047d h1:licZJFw2RwpHMqeKTCYkitsPqHNxTmd4SNR5r94FGM8=
 github.com/acarl005/stripansi v0.0.0-20180116102854-5a71ef0e047d/go.mod h1:asat636LX7Bqt5lYEZ27JNDcqxfjdBQuJ/MM4CN/Lzo=
-github.com/agentgateway/agentgateway v0.10.3 h1:z5HcuNuiz+NTZR87sU91xsjxvBD9bRP2xOhJwGbgW8Y=
-github.com/agentgateway/agentgateway v0.10.3/go.mod h1:geHd31xH5d8OrCRuRyvnDxBeqSZ9+O9VhL8VJAfcA+E=
+github.com/agentgateway/agentgateway v0.10.4 h1:9zROecngjHJcdWwqoow2N0Ngs+c+yCgAwEptdqYz6n8=
+github.com/agentgateway/agentgateway v0.10.4/go.mod h1:geHd31xH5d8OrCRuRyvnDxBeqSZ9+O9VhL8VJAfcA+E=
 github.com/agnivade/levenshtein v1.2.1 h1:EHBY3UOn1gwdy/VbFwgo4cxecRznFk7fKWN1KOX7eoM=
 github.com/agnivade/levenshtein v1.2.1/go.mod h1:QVVI16kDrtSuwcpd0p1+xMC6Z/VfhtCyDIjcwga4/DU=
 github.com/alcortesm/tgz v0.0.0-20161220082320-9c5fe88206d7/go.mod h1:6zEj6s6u/ghQa61ZWa/C2Aw3RkjiTBOix7dkqa1VLIs=

hack/utils/oss_compliance/osa_provided.md

@@ -1,7 +1,7 @@
 Name|Version|License
 ---|---|---
 [cel.dev/expr](https://cel.dev/expr)|v0.24.0|Apache License 2.0
-[agentgateway/agentgateway](https://github.com/agentgateway/agentgateway)|v0.10.3|Apache License 2.0
+[agentgateway/agentgateway](https://github.com/agentgateway/agentgateway)|v0.10.4|Apache License 2.0
 [anthropics/anthropic-sdk-go](https://github.com/anthropics/anthropic-sdk-go)|v1.13.0|MIT License
 [retry-go/v4](https://github.com/avast/retry-go)|v4.3.3|MIT License
 [xds/go](https://github.com/cncf/xds)|v0.0.0-20250501225837-2ac532fd4443|Apache License 2.0

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

@@ -439,15 +439,19 @@ spec:
                     description: |-
                       MaxMessageTimeout specifies the upper bound of override_message_timeout that may be sent from the external processing server.
                       The default value 0, which effectively disables the override_message_timeout API.
+                      Envoy: Supported
+                      Agentgateway: Not Supported (ignored)
                     type: string
                     x-kubernetes-validations:
                     - message: invalid timeout value
                       rule: matches(self, '^([0-9]{1,5}(h|m|s|ms)){1,4}$')
                     - message: timeout must be at least 1ms.
                       rule: duration(self) >= duration('1ms')
                   messageTimeout:
-                    description: MessageTimeout is the timeout for each message sent
-                      to the external processing server.
+                    description: |-
+                      MessageTimeout is the timeout for each message sent to the external processing server.
+                      Envoy: Supported
+                      Agentgateway: Not Supported (ignored)
                     type: string
                     x-kubernetes-validations:
                     - message: invalid timeout value
@@ -458,6 +462,8 @@ spec:
                     description: |-
                       MetadataOptions allows configuring metadata namespaces to forwarded or received from the external
                       processing server.
+                      Envoy: Supported
+                      Agentgateway: Not Supported (ignored)
                     properties:
                       forwarding:
                         description: Forwarding defines the typed or untyped dynamic
@@ -477,8 +483,10 @@ spec:
                         type: object
                     type: object
                   processingMode:
-                    description: ProcessingMode defines how the filter should interact
-                      with the request/response streams.
+                    description: |-
+                      ProcessingMode defines how the filter should interact with the request/response streams.
+                      Envoy: Supported
+                      Agentgateway: Not Supported (ignored)
                     properties:
                       requestBodyMode:
                         default: NONE
@@ -540,12 +548,13 @@ 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.
+                      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
                     - Clear
@@ -555,6 +564,8 @@ spec:
                     description: |-
                       StatPrefix is an optional prefix to include when emitting stats from the extproc filter,
                       enabling different instances of the filter to have unique stats.
+                      Envoy: Supported
+                      Agentgateway: Not Supported (ignored)
                     minLength: 1
                     type: string
                 required:

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

@@ -1033,6 +1033,8 @@ spec:
                     description: |-
                       Disable all external processing filters.
                       Can be used to disable external processing policies applied at a higher level in the config hierarchy.
+                      Envoy: Supported
+                      Agentgateway: Not Supported (ignored)
                     type: object
                   extensionRef:
                     description: ExtensionRef references the GatewayExtension that
@@ -1055,8 +1057,10 @@ spec:
                     - name
                     type: object
                   processingMode:
-                    description: ProcessingMode defines how the filter should interact
-                      with the request/response streams
+                    description: |-
+                      ProcessingMode defines how the filter should interact with the request/response streams
+                      Envoy: Supported
+                      Agentgateway: Not Supported (ignored)
                     properties:
                       requestBodyMode:
                         default: NONE

pkg/agentgateway/plugins/traffic_plugin.go

@@ -42,6 +42,7 @@ const (
 	globalRateLimitPolicySuffix = ":rl-global"
 	transformationPolicySuffix  = ":transformation"
 	csrfPolicySuffix            = ":csrf"
+	extprocPolicySuffix         = ":ext-proc"
 )
 
 var logger = logging.New("agentgateway/plugins")
@@ -398,6 +399,16 @@ func translateTrafficPolicyToAgw(
 		agwPolicies = append(agwPolicies, csrfPolicies...)
 	}
 
+	// Process extproc policies if present
+	if trafficPolicy.Spec.ExtProc != nil {
+		extProcPolicies, err := processExtProcPolicy(ctx, gatewayExtensions, trafficPolicy, policyName, policyTarget)
+		if err != nil {
+			logger.Error("error processing extproc policy", "error", err)
+			errs = append(errs, err)
+		}
+		agwPolicies = append(agwPolicies, extProcPolicies...)
+	}
+
 	return agwPolicies, errors.Join(errs...)
 }
 
@@ -864,6 +875,115 @@ func processRateLimitPolicy(ctx krt.HandlerContext, gatewayExtensions krt.Collec
 	return agwPolicies, errors.Join(errs...)
 }
 
+func processExtProcPolicy(ctx krt.HandlerContext, gatewayExtensions krt.Collection[*v1alpha1.GatewayExtension], trafficPolicy *v1alpha1.TrafficPolicy, policyName string, policyTarget *api.PolicyTarget) ([]AgwPolicy, error) {
+	var errs []error
+
+	// validate that unsupported ExtProcPolicy fields are not set
+	if err := validateExtProcPolicy(trafficPolicy.Spec.ExtProc); err != nil {
+		errs = append(errs, err)
+	}
+
+	gwExt, err := lookupGatewayExtension(ctx, gatewayExtensions, *trafficPolicy.Spec.ExtProc.ExtensionRef, trafficPolicy.Namespace, v1alpha1.GatewayExtensionTypeExtProc)
+	if err != nil {
+		return nil, err
+	}
+
+	extProc := (*gwExt).Spec.ExtProc
+	if extProc == nil {
+		return nil, fmt.Errorf("extproc provider is missing from gateway extension %s/%s", gwExt.Namespace, gwExt.Namespace)
+	}
+
+	// validate that unsupported ExtProcProvider fields are not set
+	if err := validateExtProcProvider(extProc); err != nil {
+		errs = append(errs, err)
+	}
+
+	var extProcSvcTarget *api.BackendReference
+	if extProc.GrpcService != nil && extProc.GrpcService.BackendRef != nil {
+		var err error
+		extProcSvcTarget, err = buildAGWServiceRef(extProc.GrpcService.BackendRef, trafficPolicy.Namespace)
+		if err != nil {
+			return nil, fmt.Errorf("failed to build extproc service reference: %w", err)
+		}
+	}
+
+	if extProcSvcTarget == nil {
+		return nil, fmt.Errorf("extproc policy %s/%s missing backendRef in gateway extension %s/%s",
+			trafficPolicy.Namespace, trafficPolicy.Name, (*gwExt).Namespace, (*gwExt).Name)
+	}
+
+	failureMode := api.PolicySpec_ExtProc_FAIL_CLOSED
+	if extProc.FailOpen {
+		failureMode = api.PolicySpec_ExtProc_FAIL_OPEN
+	}
+
+	extProcPolicy := &api.Policy{
+		Name:   policyName + extprocPolicySuffix + attachmentName(policyTarget),
+		Target: policyTarget,
+		Spec: &api.PolicySpec{
+			Kind: &api.PolicySpec_ExtProc_{
+				ExtProc: &api.PolicySpec_ExtProc{
+					Target:      extProcSvcTarget,
+					FailureMode: failureMode,
+				},
+			},
+		},
+	}
+
+	logger.Debug("generated ExtProc policy",
+		"policy", trafficPolicy.Name,
+		"agentgateway_policy", extProcPolicy.Name,
+		"target", extProcSvcTarget)
+
+	return []AgwPolicy{{Policy: extProcPolicy}}, errors.Join(errs...)
+}
+
+// validateExtProcPolicy validates that unsupported ExtProcPolicy fields are not set.
+func validateExtProcPolicy(policy *v1alpha1.ExtProcPolicy) error {
+	var errs []error
+
+	if policy.ProcessingMode != nil {
+		errs = append(errs, fmt.Errorf("processingMode field is not supported for agentgateway"))
+	}
+
+	if policy.Disable != nil {
+		errs = append(errs, fmt.Errorf("disable field is not supported for agentgateway"))
+	}
+
+	return errors.Join(errs...)
+}
+
+// validateExtProcProvider validates that unsupported ExtProcProvider fields are not set.
+func validateExtProcProvider(provider *v1alpha1.ExtProcProvider) error {
+	var errs []error
+
+	if provider.ProcessingMode != nil {
+		errs = append(errs, fmt.Errorf("processingMode field in ExtProcProvider is not supported for agentgateway"))
+	}
+
+	if provider.MessageTimeout != nil {
+		errs = append(errs, fmt.Errorf("messageTimeout field in ExtProcProvider is not supported for agentgateway"))
+	}
+
+	if provider.MaxMessageTimeout != nil {
+		errs = append(errs, fmt.Errorf("maxMessageTimeout field in ExtProcProvider is not supported for agentgateway"))
+	}
+
+	if provider.StatPrefix != nil {
+		errs = append(errs, fmt.Errorf("statPrefix field in ExtProcProvider is not supported for agentgateway"))
+	}
+
+	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"))
+	}
+
+	return errors.Join(errs...)
+}
+
 // processLocalRateLimitPolicy processes local rate limiting configuration
 func processLocalRateLimitPolicy(trafficPolicy *v1alpha1.TrafficPolicy, policyName string, policyTarget *api.PolicyTarget) (*AgwPolicy, error) {
 	if trafficPolicy.Spec.RateLimit.Local.TokenBucket == nil {

pkg/deployer/wellknown.go

@@ -17,7 +17,7 @@ const (
 	AgentgatewayRegistry = "ghcr.io/agentgateway"
 	// AgentgatewayDefaultTag is the default agentgateway image tag
 	// Note: should be in sync with version in go.mod and test/deployer/testdata/*
-	AgentgatewayDefaultTag = "0.10.3"
+	AgentgatewayDefaultTag = "0.10.4"
 	// SdsImage is the image of the sds container.
 	SdsImage = "sds"
 	// SdsContainerName is the name of the container in the proxy deployment for the SDS integration.

test/deployer/testdata/agentgateway-infrastructure-out.yaml

@@ -124,7 +124,7 @@ spec:
           value: "0"
       containers:
         - name: agent-gateway
-          image: "ghcr.io/agentgateway/agentgateway:0.10.3"
+          image: "ghcr.io/agentgateway/agentgateway:0.10.4"
           securityContext:
             allowPrivilegeEscalation: false
             capabilities:

test/deployer/testdata/agentgateway-omitdefaultsecuritycontext-out.yaml

@@ -96,7 +96,7 @@ spec:
       serviceAccountName: gw
       containers:
         - name: agent-gateway
-          image: "ghcr.io/agentgateway/agentgateway:0.10.3"
+          image: "ghcr.io/agentgateway/agentgateway:0.10.4"
           startupProbe:
             failureThreshold: 60
             httpGet:

test/deployer/testdata/agentgateway-omitdefaultsecuritycontext-ref-gwp-on-gw-out.yaml

@@ -96,7 +96,7 @@ spec:
       serviceAccountName: gw
       containers:
         - name: agent-gateway
-          image: "ghcr.io/agentgateway/agentgateway:0.10.3"
+          image: "ghcr.io/agentgateway/agentgateway:0.10.4"
           startupProbe:
             failureThreshold: 60
             httpGet:

test/deployer/testdata/agentgateway-out.yaml

@@ -100,7 +100,7 @@ spec:
           value: "0"
       containers:
         - name: agent-gateway
-          image: "ghcr.io/agentgateway/agentgateway:0.10.3"
+          image: "ghcr.io/agentgateway/agentgateway:0.10.4"
           securityContext:
             allowPrivilegeEscalation: false
             capabilities:

test/deployer/testdata/agentgateway-tls-out.yaml

@@ -130,7 +130,7 @@ spec:
           value: "0"
       containers:
         - name: agent-gateway
-          image: "ghcr.io/agentgateway/agentgateway:0.10.3"
+          image: "ghcr.io/agentgateway/agentgateway:0.10.4"
           securityContext:
             allowPrivilegeEscalation: false
             capabilities:

test/e2e/features/agentgateway/extproc/example/.gitignore

@@ -0,0 +1,10 @@
+# Build output
+_output/
+*.o
+*.a
+
+# Binary
+server
+
+# Go modules cache
+go.sum.bak