Grpc mutlitple mirrors

apis/v1alpha2/grpcroute_types.go

@@ -223,8 +223,8 @@ type GRPCRouteRule struct {
 	// - Implementation-specific custom filters have no API guarantees across
 	//   implementations.
 	//
-	// Specifying a core filter multiple times has unspecified or
-	// implementation-specific conformance.
+	// Specifying the same filter multiple times is not supported unless explicitly
+	// indicated in the filter.
 	//
 	// If an implementation can not support a combinations of filters, they must clearly
 	// document that limitation. In cases where incompatible or unsupported
@@ -515,6 +515,10 @@ type GRPCRouteFilter struct {
 	// Requests are sent to the specified destination, but responses from
 	// that destination are ignored.
 	//
+	// This filter can be used multiple times within the same rule. Note that
+	// not all implementations will be able to support mirroring to multiple
+	// backends.
+	//
 	// Support: Extended
 	//
 	// +optional
@@ -527,6 +531,7 @@ type GRPCRouteFilter struct {
 	//
 	// Support: Implementation-specific
 	//
+	// This filter can be used multiple times within the same rule.
 	// +optional
 	ExtensionRef *LocalObjectReference `json:"extensionRef,omitempty"`
 }

apis/v1alpha2/validation/grpcroute.go

@@ -32,6 +32,7 @@ var (
 	// repeated multiple times in a rule.
 	repeatableGRPCRouteFilters = []gatewayv1a2.GRPCRouteFilterType{
 		gatewayv1a2.GRPCRouteFilterExtensionRef,
+		gatewayv1a2.GRPCRouteFilterRequestMirror,
 	}
 	validServiceName      = `^(?i)\.?[a-z_][a-z_0-9]*(\.[a-z_][a-z_0-9]*)*$`
 	validServiceNameRegex = regexp.MustCompile(validServiceName)
@@ -165,7 +166,7 @@ func validateGRPCRouteFilters(filters []gatewayv1a2.GRPCRouteFilter, path *field
 		}
 		errs = append(errs, validateGRPCRouteFilterType(filter, path.Index(i))...)
 	}
-	// custom filters don't have any validation
+	// repeatableHTTPRouteFilters filters can be used more than once
 	for _, key := range repeatableGRPCRouteFilters {
 		delete(counts, key)
 	}

apis/v1alpha2/validation/grpcroute_test.go

@@ -236,10 +236,38 @@ func TestValidateGRPCRoute(t *testing.T) {
 					}},
 				},
 			},
+		},
+		{
+			name: "invalid GRPCRoute with duplicate RequestHeaderModifier filters",
+			rules: []gatewayv1a2.GRPCRouteRule{
+				{
+					Filters: []gatewayv1a2.GRPCRouteFilter{{
+						Type: "RequestHeaderModifier",
+						RequestHeaderModifier: &gatewayv1a2.HTTPHeaderFilter{
+							Set: []gatewayv1a2.HTTPHeader{
+								{
+									Name:  "special-header",
+									Value: "foo",
+								},
+							},
+						},
+					}, {
+						Type: "RequestHeaderModifier",
+						RequestHeaderModifier: &gatewayv1a2.HTTPRequesHTTPHeaderFiltertMirrorFilter{
+							Add: []gatewayv1a2.HTTPHeader{
+								{
+									Name:  "my-header",
+									Value: "bar",
+								},
+							}, 
+						},
+					}},
+				},
+			},
 			errs: field.ErrorList{
 				{
 					Type:     field.ErrorTypeInvalid,
-					BadValue: "RequestMirror",
+					BadValue: "RequestHeaderModifier",
 					Field:    "spec.rules[0].filters",
 					Detail:   "cannot be used multiple times in the same rule",
 				},
@@ -305,8 +333,8 @@ func TestValidateGRPCBackendUniqueFilters(t *testing.T) {
 			},
 		}},
 	}, {
-		name:     "invalid grpcRoute Rules duplicate mirror filter",
-		errCount: 1,
+		name:     "valid grpcRoute Rules duplicate mirror filter",
+		errCount: 0,
 		rules: []gatewayv1a2.GRPCRouteRule{{
 			BackendRefs: []gatewayv1a2.GRPCBackendRef{
 				{