Add GRPCRoute weighted backendRefs test

conformance/tests/grpcroute-weight.go

@@ -0,0 +1,98 @@
+/*
+Copyright 2025 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package tests
+
+import (
+	"fmt"
+	"testing"
+
+	"google.golang.org/grpc/codes"
+	"k8s.io/apimachinery/pkg/types"
+
+	v1 "sigs.k8s.io/gateway-api/apis/v1"
+	pb "sigs.k8s.io/gateway-api/conformance/echo-basic/grpcechoserver"
+	"sigs.k8s.io/gateway-api/conformance/utils/grpc"
+	"sigs.k8s.io/gateway-api/conformance/utils/kubernetes"
+	"sigs.k8s.io/gateway-api/conformance/utils/suite"
+	"sigs.k8s.io/gateway-api/conformance/utils/weight"
+	"sigs.k8s.io/gateway-api/pkg/features"
+)
+
+func init() {
+	ConformanceTests = append(ConformanceTests, GRPCRouteWeight)
+}
+
+var GRPCRouteWeight = suite.ConformanceTest{
+	ShortName:   "GRPCRouteWeight",
+	Description: "An GRPCRoute with weighted backends",
+	Manifests:   []string{"tests/grpcroute-weight.yaml"},
+	Features: []features.FeatureName{
+		features.SupportGateway,
+		features.SupportGRPCRoute,
+	},
+	Test: func(t *testing.T, suite *suite.ConformanceTestSuite) {
+		var (
+			ns      = "gateway-conformance-infra"
+			routeNN = types.NamespacedName{Name: "weighted-backends", Namespace: ns}
+			gwNN    = types.NamespacedName{Name: "same-namespace", Namespace: ns}
+			gwAddr  = kubernetes.GatewayAndRoutesMustBeAccepted(t, suite.Client, suite.TimeoutConfig, suite.ControllerName, kubernetes.NewGatewayRef(gwNN), &v1.GRPCRoute{}, true, routeNN)
+		)
+
+		t.Run("Requests should have a distribution that matches the weight", func(t *testing.T) {
+			expected := grpc.ExpectedResponse{
+				EchoRequest: &pb.EchoRequest{},
+				Response:    grpc.Response{Code: codes.OK},
+				Namespace:   "gateway-conformance-infra",
+			}
+
+			// Assert request succeeds before doing our distribution check
+			grpc.MakeRequestAndExpectEventuallyConsistentResponse(t, suite.GRPCClient, suite.TimeoutConfig, gwAddr, expected)
+
+			expectedWeights := map[string]float64{
+				"grpc-infra-backend-v1": 0.7,
+				"grpc-infra-backend-v2": 0.3,
+				"grpc-infra-backend-v3": 0.0,
+			}
+
+			sender := weight.NewFunctionBasedSender(func() (string, error) {
+				uniqueExpected := expected
+				if err := grpc.AddEntropy(&uniqueExpected); err != nil {
+					return "", fmt.Errorf("error adding entropy: %w", err)
+				}
+				client := &grpc.DefaultClient{}
+				defer client.Close()
+				resp, err := client.SendRPC(t, gwAddr, uniqueExpected, suite.TimeoutConfig.MaxTimeToConsistency)
+				if err != nil {
+					return "", fmt.Errorf("failed to send gRPC request: %w", err)
+				}
+				if resp.Code != codes.OK {
+					return "", fmt.Errorf("expected OK response, got %v", resp.Code)
+				}
+				return resp.Response.GetAssertions().GetContext().GetPod(), nil
+			})
+
+			for i := 0; i < 10; i++ {
+				if err := weight.TestWeightedDistribution(sender, expectedWeights); err != nil {
+					t.Logf("Traffic distribution test failed (%d/10): %s", i+1, err)
+				} else {
+					return
+				}
+			}
+			t.Fatal("Weighted distribution tests failed")
+		})
+	},
+}

conformance/tests/grpcroute-weight.yaml

@@ -0,0 +1,19 @@
+apiVersion: gateway.networking.k8s.io/v1
+kind: GRPCRoute
+metadata:
+  name: weighted-backends
+  namespace: gateway-conformance-infra
+spec:
+  parentRefs:
+  - name: same-namespace
+  rules:
+  - backendRefs:
+    - name: grpc-infra-backend-v1
+      port: 8080
+      weight: 70
+    - name: grpc-infra-backend-v2
+      port: 8080
+      weight: 30
+    - name: grpc-infra-backend-v3
+      port: 8080
+      weight: 0

conformance/tests/httproute-weight.go

@@ -17,21 +17,15 @@ limitations under the License.
 package tests
 
 import (
-	"cmp"
-	"errors"
 	"fmt"
-	"math"
-	"slices"
-	"strings"
-	"sync"
 	"testing"
 
-	"golang.org/x/sync/errgroup"
 	"k8s.io/apimachinery/pkg/types"
 
 	"sigs.k8s.io/gateway-api/conformance/utils/http"
 	"sigs.k8s.io/gateway-api/conformance/utils/kubernetes"
 	"sigs.k8s.io/gateway-api/conformance/utils/suite"
+	"sigs.k8s.io/gateway-api/conformance/utils/weight"
 	"sigs.k8s.io/gateway-api/pkg/features"
 )
 
@@ -67,8 +61,30 @@ var HTTPRouteWeight = suite.ConformanceTest{
 			// Assert request succeeds before doing our distribution check
 			http.MakeRequestAndExpectEventuallyConsistentResponse(t, suite.RoundTripper, suite.TimeoutConfig, gwAddr, expected)
 
+			expectedWeights := map[string]float64{
+				"infra-backend-v1": 0.7,
+				"infra-backend-v2": 0.3,
+				"infra-backend-v3": 0.0,
+			}
+
+			sender := weight.NewFunctionBasedSender(func() (string, error) {
+				uniqueExpected := expected
+				if err := http.AddEntropy(&uniqueExpected); err != nil {
+					return "", fmt.Errorf("error adding entropy: %w", err)
+				}
+				req := http.MakeRequest(t, &uniqueExpected, gwAddr, "HTTP", "http")
+				cReq, cRes, err := suite.RoundTripper.CaptureRoundTrip(req)
+				if err != nil {
+					return "", fmt.Errorf("failed to roundtrip request: %w", err)
+				}
+				if err := http.CompareRoundTrip(t, &req, cReq, cRes, expected); err != nil {
+					return "", fmt.Errorf("response expectation failed for request: %w", err)
+				}
+				return cReq.Pod, nil
+			})
+
 			for i := 0; i < 10; i++ {
-				if err := testDistribution(t, suite, gwAddr, expected); err != nil {
+				if err := weight.TestWeightedDistribution(sender, expectedWeights); err != nil {
 					t.Logf("Traffic distribution test failed (%d/10): %s", i+1, err)
 				} else {
 					return
@@ -78,85 +94,3 @@ var HTTPRouteWeight = suite.ConformanceTest{
 		})
 	},
 }
-
-func testDistribution(t *testing.T, suite *suite.ConformanceTestSuite, gwAddr string, expected http.ExpectedResponse) error {
-	const (
-		concurrentRequests  = 10
-		tolerancePercentage = 0.05
-		totalRequests       = 500.0
-	)
-	var (
-		roundTripper = suite.RoundTripper
-
-		g               errgroup.Group
-		seenMutex       sync.Mutex
-		seen            = make(map[string]float64, 3 /* number of backends */)
-		expectedWeights = map[string]float64{
-			"infra-backend-v1": 0.7,
-			"infra-backend-v2": 0.3,
-			"infra-backend-v3": 0.0,
-		}
-	)
-	g.SetLimit(concurrentRequests)
-	for i := 0.0; i < totalRequests; i++ {
-		g.Go(func() error {
-			uniqueExpected := expected
-			if err := http.AddEntropy(&uniqueExpected); err != nil {
-				return fmt.Errorf("error adding entropy: %w", err)
-			}
-			req := http.MakeRequest(t, &uniqueExpected, gwAddr, "HTTP", "http")
-			cReq, cRes, err := roundTripper.CaptureRoundTrip(req)
-			if err != nil {
-				return fmt.Errorf("failed to roundtrip request: %w", err)
-			}
-			if err := http.CompareRoundTrip(t, &req, cReq, cRes, expected); err != nil {
-				return fmt.Errorf("response expectation failed for request: %w", err)
-			}
-
-			seenMutex.Lock()
-			defer seenMutex.Unlock()
-
-			for expectedBackend := range expectedWeights {
-				if strings.HasPrefix(cReq.Pod, expectedBackend) {
-					seen[expectedBackend]++
-					return nil
-				}
-			}
-
-			return fmt.Errorf("request was handled by an unexpected pod %q", cReq.Pod)
-		})
-	}
-
-	if err := g.Wait(); err != nil {
-		return fmt.Errorf("error while sending requests: %w", err)
-	}
-
-	var errs []error
-	if len(seen) != 2 {
-		errs = append(errs, fmt.Errorf("expected only two backends to receive traffic"))
-	}
-
-	for wantBackend, wantPercent := range expectedWeights {
-		gotCount, ok := seen[wantBackend]
-
-		if !ok && wantPercent != 0.0 {
-			errs = append(errs, fmt.Errorf("expect traffic to hit backend %q - but none was received", wantBackend))
-			continue
-		}
-
-		gotPercent := gotCount / totalRequests
-
-		if math.Abs(gotPercent-wantPercent) > tolerancePercentage {
-			errs = append(errs, fmt.Errorf("backend %q weighted traffic of %v not within tolerance %v (+/-%f)",
-				wantBackend,
-				gotPercent,
-				wantPercent,
-				tolerancePercentage,
-			))
-		}
-	}
-	slices.SortFunc(errs, func(a, b error) int {
-		return cmp.Compare(a.Error(), b.Error())
-	})
-	return errors.Join(errs...)
-}

conformance/tests/mesh/grpcroute-weight.go

@@ -0,0 +1,100 @@
+/*
+Copyright 2025 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package meshtests
+
+import (
+	"fmt"
+	"testing"
+
+	"google.golang.org/grpc/codes"
+
+	pb "sigs.k8s.io/gateway-api/conformance/echo-basic/grpcechoserver"
+	"sigs.k8s.io/gateway-api/conformance/utils/echo"
+	"sigs.k8s.io/gateway-api/conformance/utils/grpc"
+	"sigs.k8s.io/gateway-api/conformance/utils/suite"
+	"sigs.k8s.io/gateway-api/conformance/utils/weight"
+	"sigs.k8s.io/gateway-api/pkg/features"
+)
+
+func init() {
+	MeshConformanceTests = append(MeshConformanceTests, MeshGRPCRouteWeight)
+}
+
+var MeshGRPCRouteWeight = suite.ConformanceTest{
+	ShortName:   "MeshGRPCRouteWeight",
+	Description: "A GRPCRoute with weighted backends in mesh mode",
+	Manifests:   []string{"tests/mesh/grpcroute-weight.yaml"},
+	Features: []features.FeatureName{
+		features.SupportMesh,
+		features.SupportGRPCRoute,
+	},
+	Test: func(t *testing.T, s *suite.ConformanceTestSuite) {
+		// Connect to mesh app to get the service address
+		client := echo.ConnectToApp(t, s, echo.MeshAppEchoV1)
+
+		t.Run("Requests should have a distribution that matches the weight", func(t *testing.T) {
+			expected := grpc.ExpectedResponse{
+				EchoRequest: &pb.EchoRequest{},
+				Response:    grpc.Response{Code: codes.OK},
+				Namespace:   "gateway-conformance-mesh",
+			}
+
+			// Assert request succeeds before doing our distribution check
+			grpcClient := &grpc.DefaultClient{}
+			defer grpcClient.Close()
+			resp, err := grpcClient.SendRPC(t, client.Address+":9000", expected, s.TimeoutConfig.MaxTimeToConsistency)
+			if err != nil {
+				t.Skipf("gRPC mesh test requires gRPC support on mesh services: %v", err)
+			}
+			if resp.Code != codes.OK {
+				t.Skipf("gRPC mesh test requires working gRPC endpoints: got %v", resp.Code)
+			}
+
+			expectedWeights := map[string]float64{
+				"echo-v1": 0.7,
+				"echo-v2": 0.3,
+			}
+
+			sender := weight.NewFunctionBasedSender(func() (string, error) {
+				uniqueExpected := expected
+				if err := grpc.AddEntropy(&uniqueExpected); err != nil {
+					return "", fmt.Errorf("error adding entropy: %w", err)
+				}
+
+				grpcClient := &grpc.DefaultClient{}
+				defer grpcClient.Close()
+				resp, err := grpcClient.SendRPC(t, client.Address+":9000", uniqueExpected, s.TimeoutConfig.MaxTimeToConsistency)
+				if err != nil {
+					return "", fmt.Errorf("failed to send gRPC mesh request: %w", err)
+				}
+				if resp.Code != codes.OK {
+					return "", fmt.Errorf("expected OK response, got %v", resp.Code)
+				}
+				return resp.Response.GetAssertions().GetContext().GetPod(), nil
+			})
+
+			for i := 0; i < 10; i++ {
+				if err := weight.TestWeightedDistribution(sender, expectedWeights); err != nil {
+					t.Logf("Traffic distribution test failed (%d/10): %s", i+1, err)
+				} else {
+					return
+				}
+			}
+			t.Fatal("Weighted distribution tests failed")
+		})
+	},
+}

conformance/tests/mesh/grpcroute-weight.yaml

@@ -0,0 +1,19 @@
+apiVersion: gateway.networking.k8s.io/v1
+kind: GRPCRoute
+metadata:
+  name: mesh-grpc-weighted-backends
+  namespace: gateway-conformance-mesh
+spec:
+  parentRefs:
+  - group: ""
+    kind: Service
+    name: echo
+    port: 9000
+  rules:
+  - backendRefs:
+    - name: echo-v1
+      port: 9000
+      weight: 70
+    - name: echo-v2
+      port: 9000
+      weight: 30