conformance tests for percentage-based request mirroring

conformance/tests/httproute-request-mirror.go

@@ -57,10 +57,14 @@ var HTTPRouteRequestMirror = suite.ConformanceTest{
 					},
 				},
 				Backend: "infra-backend-v1",
-				MirroredTo: []http.BackendRef{{
-					Name:      "infra-backend-v2",
-					Namespace: ns,
-				}},
+				MirroredTo: []http.MirroredBackend{
+					{
+						BackendRef: http.BackendRef{
+							Name:      "infra-backend-v2",
+							Namespace: ns,
+						},
+					},
+				},
 				Namespace: ns,
 			},
 			{
@@ -84,10 +88,14 @@ var HTTPRouteRequestMirror = suite.ConformanceTest{
 				},
 				Namespace: ns,
 				Backend:   "infra-backend-v1",
-				MirroredTo: []http.BackendRef{{
-					Name:      "infra-backend-v2",
-					Namespace: ns,
-				}},
+				MirroredTo: []http.MirroredBackend{
+					{
+						BackendRef: http.BackendRef{
+							Name:      "infra-backend-v2",
+							Namespace: ns,
+						},
+					},
+				},
 			},
 		}
 		for i := range testCases {

conformance/tests/httproute-request-multiple-mirrors.go

@@ -58,14 +58,18 @@ var HTTPRouteRequestMultipleMirrors = suite.ConformanceTest{
 					},
 				},
 				Backend: "infra-backend-v1",
-				MirroredTo: []http.BackendRef{
+				MirroredTo: []http.MirroredBackend{
 					{
-						Name:      "infra-backend-v2",
-						Namespace: ns,
+						BackendRef: http.BackendRef{
+							Name:      "infra-backend-v2",
+							Namespace: ns,
+						},
 					},
 					{
-						Name:      "infra-backend-v3",
-						Namespace: ns,
+						BackendRef: http.BackendRef{
+							Name:      "infra-backend-v3",
+							Namespace: ns,
+						},
 					},
 				},
 				Namespace: ns,
@@ -90,14 +94,18 @@ var HTTPRouteRequestMultipleMirrors = suite.ConformanceTest{
 				},
 				Namespace: ns,
 				Backend:   "infra-backend-v1",
-				MirroredTo: []http.BackendRef{
+				MirroredTo: []http.MirroredBackend{
 					{
-						Name:      "infra-backend-v2",
-						Namespace: ns,
+						BackendRef: http.BackendRef{
+							Name:      "infra-backend-v2",
+							Namespace: ns,
+						},
 					},
 					{
-						Name:      "infra-backend-v3",
-						Namespace: ns,
+						BackendRef: http.BackendRef{
+							Name:      "infra-backend-v3",
+							Namespace: ns,
+						},
 					},
 				},
 			},

conformance/tests/httproute-request-percentage-mirror.go

@@ -0,0 +1,236 @@
+/*
+Copyright 2024 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 (
+	"errors"
+	"fmt"
+	"regexp"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	"k8s.io/apimachinery/pkg/types"
+
+	"sigs.k8s.io/gateway-api/conformance/utils/config"
+	"sigs.k8s.io/gateway-api/conformance/utils/http"
+	"sigs.k8s.io/gateway-api/conformance/utils/kubernetes"
+	"sigs.k8s.io/gateway-api/conformance/utils/roundtripper"
+	"sigs.k8s.io/gateway-api/conformance/utils/suite"
+	"sigs.k8s.io/gateway-api/conformance/utils/tlog"
+	"sigs.k8s.io/gateway-api/pkg/features"
+)
+
+const (
+	concurrentRequests    = 10
+	tolerancePercentage   = 5.0
+	totalRequests         = 500.0
+	numDistributionChecks = 5
+)
+
+func init() {
+	ConformanceTests = append(ConformanceTests, HTTPRouteRequestPercentageMirror)
+}
+
+var HTTPRouteRequestPercentageMirror = suite.ConformanceTest{
+	ShortName:   "HTTPRouteRequestPercentageMirror",
+	Description: "An HTTPRoute with percentage based request mirroring",
+	Manifests:   []string{"tests/httproute-request-percentage-mirror.yaml"},
+	Features: []features.FeatureName{
+		features.SupportGateway,
+		features.SupportHTTPRoute,
+		// features.SupportHTTPRouteRequestPercentageMirror,
+	},
+	Test: func(t *testing.T, suite *suite.ConformanceTestSuite) {
+		var (
+			ns      = "gateway-conformance-infra"
+			routeNN = types.NamespacedName{Name: "request-percentage-mirror", Namespace: ns}
+			gwNN    = types.NamespacedName{Name: "same-namespace", Namespace: ns}
+			gwAddr  = kubernetes.GatewayAndHTTPRoutesMustBeAccepted(t, suite.Client, suite.TimeoutConfig, suite.ControllerName, kubernetes.NewGatewayRef(gwNN), routeNN)
+		)
+
+		kubernetes.HTTPRouteMustHaveResolvedRefsConditionsTrue(t, suite.Client, suite.TimeoutConfig, routeNN, gwNN)
+
+		testCases := []http.ExpectedResponse{
+			{
+				Request:   http.Request{Path: "/percent-mirror"},
+				Namespace: ns,
+				ExpectedRequest: &http.ExpectedRequest{
+					Request: http.Request{
+						Path: "/percent-mirror",
+					},
+				},
+				Backend: "infra-backend-v1",
+				MirroredTo: []http.MirroredBackend{
+					{
+						BackendRef: http.BackendRef{
+							Name:      "infra-backend-v2",
+							Namespace: ns,
+						},
+						Percent: ptrTo(int32(20)),
+					},
+				},
+			}, {
+				Request:   http.Request{Path: "/percent-mirror-fraction"},
+				Namespace: ns,
+				ExpectedRequest: &http.ExpectedRequest{
+					Request: http.Request{
+						Path: "/percent-mirror-fraction",
+					},
+				},
+				Backend: "infra-backend-v1",
+				MirroredTo: []http.MirroredBackend{
+					{
+						BackendRef: http.BackendRef{
+							Name:      "infra-backend-v2",
+							Namespace: ns,
+						},
+						Percent: ptrTo(int32(50)),
+					},
+				},
+			}, {
+				Request: http.Request{
+					Path: "/percent-mirror-and-modify-headers",
+					Headers: map[string]string{
+						"X-Header-Remove":     "remove-val",
+						"X-Header-Add-Append": "append-val-1",
+					},
+				},
+				ExpectedRequest: &http.ExpectedRequest{
+					Request: http.Request{
+						Path: "/percent-mirror-and-modify-headers",
+						Headers: map[string]string{
+							"X-Header-Add":        "header-val-1",
+							"X-Header-Add-Append": "append-val-1,header-val-2",
+							"X-Header-Set":        "set-overwrites-values",
+						},
+					},
+					AbsentHeaders: []string{"X-Header-Remove"},
+				},
+				Namespace: ns,
+				Backend:   "infra-backend-v1",
+				MirroredTo: []http.MirroredBackend{
+					{
+						BackendRef: http.BackendRef{
+							Name:      "infra-backend-v2",
+							Namespace: ns,
+						},
+						Percent: ptrTo(int32(35)),
+					},
+				},
+			},
+		}
+
+		for i := range testCases {
+			expected := testCases[i]
+			t.Run(expected.GetTestCaseName(i), func(t *testing.T) {
+				// Assert request succeeds before doing our distribution check
+				http.MakeRequestAndExpectEventuallyConsistentResponse(t, suite.RoundTripper, suite.TimeoutConfig, gwAddr, expected)
+
+				// Override to not have more requests than expected
+				suite.TimeoutConfig.RequiredConsecutiveSuccesses = 1
+				// used to limit number of parallel go routines
+				semaphore := make(chan struct{}, concurrentRequests)
+				var wg sync.WaitGroup
+
+				for k := 0; k < numDistributionChecks; k++ {
+					time := time.Now()
+					for j := 0; j < totalRequests; j++ {
+						wg.Add(1)
+						semaphore <- struct{}{}
+						go func(t *testing.T, r roundtripper.RoundTripper, timeoutConfig config.TimeoutConfig, gwAddr string, expected http.ExpectedResponse) {
+							defer wg.Done()
+							defer func() { <-semaphore }()
+							http.MakeRequestAndExpectEventuallyConsistentResponse(t, r, timeoutConfig, gwAddr, expected)
+						}(t, suite.RoundTripper, suite.TimeoutConfig, gwAddr, expected)
+					}
+					wg.Wait()
+
+					if err := testMirroredRequestsDistribution(t, suite, expected, time); err != nil {
+						t.Logf("Traffic distribution test failed (%d/%d): %s", k+1, numDistributionChecks, err)
+					} else {
+						return
+					}
+				}
+				t.Fatal("Percentage based mirror distribution tests failed")
+			})
+		}
+	},
+}
+
+func testMirroredRequestsDistribution(t *testing.T, suite *suite.ConformanceTestSuite, expected http.ExpectedResponse, timeVal time.Time) error {
+	mirrorPods := expected.MirroredTo
+	for i, mirrorPod := range mirrorPods {
+		if mirrorPod.Name == "" {
+			tlog.Fatalf(t, "Mirrored BackendRef[%d].Name wasn't provided in the testcase, this test should only check http request mirror.", i)
+		}
+	}
+
+	var mu sync.Mutex
+	mirroredCounts := make(map[string]int)
+
+	for _, mirrorPod := range mirrorPods {
+		require.Eventually(t, func() bool {
+			mirrorLogRegexp := regexp.MustCompile(fmt.Sprintf("Echoing back request made to \\%s to client", expected.Request.Path))
+
+			tlog.Log(t, "Searching for the mirrored request log")
+			tlog.Logf(t, `Reading "%s/%s" logs`, mirrorPod.Namespace, mirrorPod.Name)
+			logs, err := kubernetes.DumpEchoLogs(mirrorPod.Namespace, mirrorPod.Name, suite.Client, suite.Clientset, timeVal)
+			if err != nil {
+				tlog.Logf(t, `Couldn't read "%s/%s" logs: %v`, mirrorPod.Namespace, mirrorPod.Name, err)
+				return false
+			}
+
+			count := 0
+			for _, log := range logs {
+				if mirrorLogRegexp.MatchString(log) {
+					count++
+				}
+			}
+			mu.Lock()
+			mirroredCounts[mirrorPod.Name] += count
+			mu.Unlock()
+
+			return true
+		}, 60*time.Second, time.Millisecond*100, fmt.Sprintf(`Couldn't verify the logs for "%s/%s"`, mirrorPod.Namespace, mirrorPod.Name))
+	}
+
+	var errs []error
+
+	for _, mirrorPod := range mirrorPods {
+		expected := float64(totalRequests) * float64(*mirrorPod.Percent) / 100.0
+		minExpected := expected * (1 - tolerancePercentage/100)
+		maxExpected := expected * (1 + tolerancePercentage/100)
+
+		actual := float64(mirroredCounts[mirrorPod.Name])
+		tlog.Logf(t, "Pod: %s, Expected: %f (min: %f, max: %f), Actual: %f", mirrorPod.Name, expected, minExpected, maxExpected, actual)
+
+		if actual < minExpected || actual > maxExpected {
+			errs = append(errs, fmt.Errorf("Pod %s did not meet the mirroring percentage within tolerance. Expected between %f and %f, but got %f", mirrorPod.Name, minExpected, maxExpected, actual))
+		}
+	}
+	if len(errs) > 0 {
+		return errors.Join(errs...)
+	}
+	tlog.Log(t, "Validated mirrored request logs across all desired backends within the given tolerance")
+	return nil
+}
+
+func ptrTo[T any](a T) *T {
+	return &a
+}

conformance/tests/httproute-request-percentage-mirror.yaml

@@ -0,0 +1,71 @@
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: request-percentage-mirror
+  namespace: gateway-conformance-infra
+spec:
+  parentRefs:
+  - name: same-namespace
+  rules:
+  - matches:
+    - path:
+        type: PathPrefix
+        value: /percent-mirror
+    filters:
+    - type: RequestMirror
+      requestMirror:
+        backendRef:
+          name: infra-backend-v2
+          namespace: gateway-conformance-infra
+          port: 8080
+        percent: 20
+    backendRefs:
+    - name: infra-backend-v1
+      port: 8080
+      namespace: gateway-conformance-infra
+  - matches:
+    - path:
+        type: PathPrefix
+        value: /percent-mirror-fraction
+    filters:
+    - type: RequestMirror
+      requestMirror:
+        backendRef:
+          name: infra-backend-v2
+          namespace: gateway-conformance-infra
+          port: 8080
+        fraction:
+          numerator: 25
+          denominator: 50
+    backendRefs:
+    - name: infra-backend-v1
+      port: 8080
+      namespace: gateway-conformance-infra
+  - matches:
+    - path:
+        type: PathPrefix
+        value: /percent-mirror-and-modify-headers
+    filters:
+    - type: RequestHeaderModifier
+      requestHeaderModifier:
+        set:
+        - name: X-Header-Set
+          value: set-overwrites-values
+        add:
+        - name: X-Header-Add
+          value: header-val-1
+        - name: X-Header-Add-Append
+          value: header-val-2
+        remove:
+        - X-Header-Remove
+    - type: RequestMirror
+      requestMirror:
+        backendRef:
+          name: infra-backend-v2
+          namespace: gateway-conformance-infra
+          port: 8080
+        percent: 35
+    backendRefs:
+    - name: infra-backend-v1
+      port: 8080
+      namespace: gateway-conformance-infra