feat(translator): ext-proc attributes

examples/grpc-ext-proc/main.go

@@ -210,6 +210,16 @@ func (s *extProcServer) Process(srv envoy_service_proc_v3.ExternalProcessor_Proc
 		resp := &envoy_service_proc_v3.ProcessingResponse{}
 		switch v := req.Request.(type) {
 		case *envoy_service_proc_v3.ProcessingRequest_RequestHeaders:
+			xdsRouteName := ""
+
+			if req.Attributes != nil {
+				if epa, ok := req.Attributes["envoy.filters.http.ext_proc"]; ok {
+					if rqa, ok := epa.Fields["xds.route_name"]; ok {
+						xdsRouteName = rqa.GetStringValue()
+					}
+				}
+			}
+
 			xrch := ""
 			if v.RequestHeaders != nil {
 				hdrs := v.RequestHeaders.Headers.GetHeaders()
@@ -230,6 +240,12 @@ func (s *extProcServer) Process(srv envoy_service_proc_v3.ExternalProcessor_Proc
 									RawValue: []byte("true"),
 								},
 							},
+							{
+								Header: &envoy_api_v3_core.HeaderValue{
+									Key:      "x-request-xds-route-name",
+									RawValue: []byte(xdsRouteName),
+								},
+							},
 						},
 					},
 				},
@@ -257,8 +273,19 @@ func (s *extProcServer) Process(srv envoy_service_proc_v3.ExternalProcessor_Proc
 					RequestHeaders: rhq,
 				},
 			}
+
 			break
 		case *envoy_service_proc_v3.ProcessingRequest_ResponseHeaders:
+
+			respXDSRouteName := ""
+
+			if req.Attributes != nil {
+				if epa, ok := req.Attributes["envoy.filters.http.ext_proc"]; ok {
+					if rsa, ok := epa.Fields["xds.route_name"]; ok {
+						respXDSRouteName = rsa.GetStringValue()
+					}
+				}
+			}
 			rhq := &envoy_service_proc_v3.HeadersResponse{
 				Response: &envoy_service_proc_v3.CommonResponse{
 					HeaderMutation: &envoy_service_proc_v3.HeaderMutation{
@@ -269,6 +296,12 @@ func (s *extProcServer) Process(srv envoy_service_proc_v3.ExternalProcessor_Proc
 									RawValue: []byte("true"),
 								},
 							},
+							{
+								Header: &envoy_api_v3_core.HeaderValue{
+									Key:      "x-response-xds-route-name",
+									RawValue: []byte(respXDSRouteName),
+								},
+							},
 						},
 					},
 				},

internal/gatewayapi/envoyextensionpolicy.go

@@ -481,13 +481,21 @@ func (t *Translator) buildExtProc(
 			if extProc.ProcessingMode.Request.Body != nil {
 				extProcIR.RequestBodyProcessingMode = ptr.To(ir.ExtProcBodyProcessingMode(*extProc.ProcessingMode.Request.Body))
 			}
+
+			if extProc.ProcessingMode.Request.Attributes != nil {
+				extProcIR.RequestAttributes = append(extProcIR.RequestAttributes, extProc.ProcessingMode.Request.Attributes...)
+			}
 		}
 
 		if extProc.ProcessingMode.Response != nil {
 			extProcIR.ResponseHeaderProcessing = true
 			if extProc.ProcessingMode.Response.Body != nil {
 				extProcIR.ResponseBodyProcessingMode = ptr.To(ir.ExtProcBodyProcessingMode(*extProc.ProcessingMode.Response.Body))
 			}
+
+			if extProc.ProcessingMode.Response.Attributes != nil {
+				extProcIR.ResponseAttributes = append(extProcIR.ResponseAttributes, extProc.ProcessingMode.Response.Attributes...)
+			}
 		}
 	}
 

internal/gatewayapi/testdata/envoyextensionpolicy-with-extproc-with-backendtlspolicy.in.yaml

@@ -203,8 +203,13 @@ envoyExtensionPolicies:
       processingMode:
         request:
           body: Buffered
+          attributes:
+          - request.path
         response:
           body: Streamed
+          attributes:
+          - xds.route_metadata
+          - connection.requested_server_name
       messageTimeout: 5s
       failOpen: true
 - apiVersion: gateway.envoyproxy.io/v1alpha1

internal/gatewayapi/testdata/envoyextensionpolicy-with-extproc-with-backendtlspolicy.out.yaml

@@ -113,8 +113,13 @@ envoyExtensionPolicies:
       messageTimeout: 5s
       processingMode:
         request:
+          attributes:
+          - request.path
           body: Buffered
         response:
+          attributes:
+          - xds.route_metadata
+          - connection.requested_server_name
           body: Streamed
     targetRef:
       group: gateway.networking.k8s.io
@@ -363,8 +368,13 @@ xdsIR:
             failOpen: true
             messageTimeout: 5s
             name: envoyextensionpolicy/default/policy-for-gateway/extproc/0
+            requestAttributes:
+            - request.path
             requestBodyProcessingMode: Buffered
             requestHeaderProcessing: true
+            responseAttributes:
+            - xds.route_metadata
+            - connection.requested_server_name
             responseBodyProcessingMode: Streamed
             responseHeaderProcessing: true
         hostname: www.bar.com

internal/ir/xds.go

@@ -2602,6 +2602,14 @@ type ExtProc struct {
 
 	// ResponseBodyProcessingMode Defines response body processing
 	ResponseBodyProcessingMode *ExtProcBodyProcessingMode `json:"responseBodyProcessingMode,omitempty" yaml:"responseBodyProcessingMode,omitempty"`
+
+	// RequestAttributes defines which envoy attributes are provided as context to external processor
+	// when processing requests
+	RequestAttributes []string `json:"requestAttributes,omitempty" yaml:"requestAttributes,omitempty"`
+
+	// ResponseAttributes defines which envoy attributes are provided as context to external processor
+	// when processing responses
+	ResponseAttributes []string `json:"responseAttributes,omitempty" yaml:"responseAttributes,omitempty"`
 }
 
 // Wasm holds the information associated with the Wasm extensions.

internal/xds/translator/extproc.go

@@ -137,6 +137,18 @@ func extProcConfig(extProc ir.ExtProc) *extprocv3.ExternalProcessor {
 		config.ProcessingMode.ResponseHeaderMode = extprocv3.ProcessingMode_SEND
 	}
 
+	if extProc.RequestAttributes != nil {
+		var attrs []string
+		attrs = append(attrs, extProc.RequestAttributes...)
+		config.RequestAttributes = attrs
+	}
+
+	if extProc.ResponseAttributes != nil {
+		var attrs []string
+		attrs = append(attrs, extProc.ResponseAttributes...)
+		config.ResponseAttributes = attrs
+	}
+
 	return config
 }
 

internal/xds/translator/testdata/in/xds-ir/ext-proc.yaml

@@ -23,8 +23,13 @@ http:
             - name: envoyextensionpolicy/default/policy-for-route-2/extproc/0
               failOpen: true
               messageTimeout: 5s
+              requestAttributes:
+                - xds.route_metadata
+                - connection.requested_server_name
               requestHeaderProcessing: true
               requestBodyProcessingMode: Buffered
+              responseAttributes:
+                - request.path
               responseBodyProcessingMode: Streamed
               authority: grpc-backend-4.default:4000
               destination:
@@ -71,6 +76,11 @@ http:
             - name: envoyextensionpolicy/envoy-gateway/policy-for-gateway-1/extproc/0
               failOpen: false
               messageTimeout: 15s
+              requestAttributes:
+                - xds.route_metadata
+                - connection.requested_server_name
+              responseAttributes:
+                - request.path
               authority: grpc-backend.envoy-gateway:9000
               destination:
                 name: envoyextensionpolicy/envoy-gateway/policy-for-gateway-1/0/grpc-backend

internal/xds/translator/testdata/out/xds-ir/ext-proc.listeners.yaml

@@ -32,6 +32,11 @@
               responseBodyMode: STREAMED
               responseHeaderMode: SKIP
               responseTrailerMode: SKIP
+            requestAttributes:
+            - xds.route_metadata
+            - connection.requested_server_name
+            responseAttributes:
+            - request.path
         - disabled: true
           name: envoy.filters.http.ext_proc/envoyextensionpolicy/default/policy-for-route-1/extproc/0
           typedConfig:
@@ -78,6 +83,11 @@
               requestTrailerMode: SKIP
               responseHeaderMode: SKIP
               responseTrailerMode: SKIP
+            requestAttributes:
+            - xds.route_metadata
+            - connection.requested_server_name
+            responseAttributes:
+            - request.path
         - name: envoy.filters.http.router
           typedConfig:
             '@type': type.googleapis.com/envoy.extensions.filters.http.router.v3.Router

test/e2e/testdata/ext-proc-envoyextensionpolicy.yaml

@@ -51,8 +51,12 @@ spec:
       namespace: gateway-conformance-infra
       port: 9002
     processingMode:
-      request: {}
-      response: {}
+      request:
+        attributes:
+        - xds.route_name
+      response:
+        attributes:
+        - xds.route_name
 ---
 apiVersion: gateway.envoyproxy.io/v1alpha1
 kind: EnvoyExtensionPolicy

test/e2e/tests/ext_proc.go

@@ -63,16 +63,24 @@ var ExtProcTest = suite.ConformanceTest{
 					Request: http.Request{
 						Path: "/processor",
 						Headers: map[string]string{
-							"x-request-ext-processed":          "true",     // header added by ext-processor to backend-bound request
-							"x-request-client-header-received": "original", // this is the original client header preserved by ext-proc in a new header
-							"x-request-client-header":          "mutated",  // this is the mutated value expected to reach upstream
+							// header added by ext-processor to backend-bound request
+							"x-request-ext-processed": "true",
+							// this is the original client header preserved by ext-proc in a new header
+							"x-request-client-header-received": "original",
+							// this is the mutated value expected to reach upstream
+							"x-request-client-header": "mutated",
+							// header added by ext-processor to request based on the xds.route_name attribute
+							"x-request-xds-route-name": "httproute/gateway-conformance-infra/http-with-ext-proc/rule/0/match/0/www_example_com",
 						},
 					},
 				},
 				Response: http.Response{
 					StatusCode: 200,
 					Headers: map[string]string{
-						"x-response-ext-processed": "true", // header added by ext-processor to client-bound response
+						// header added by ext-processor to client-bound response
+						"x-response-ext-processed": "true",
+						// header added by ext-processor to response based on the xds.cluster_name attribute
+						"x-response-xds-route-name": "httproute/gateway-conformance-infra/http-with-ext-proc/rule/0/match/0/www_example_com",
 					},
 				},
 				Namespace: ns,