conformance: add a conformance test for cookie based session persistence

conformance/tests/httproute-session-persistence-cookie.go

@@ -0,0 +1,105 @@
+/*
+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"
+	stdhttp "net/http"
+	"testing"
+
+	"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/pkg/features"
+)
+
+func init() {
+	ConformanceTests = append(ConformanceTests, HTTPRouteSessionPersistenceCookie)
+}
+
+var HTTPRouteSessionPersistenceCookie = suite.ConformanceTest{
+	ShortName:   "HTTPRouteSessionPersistenceCookie",
+	Description: "An HTTPRoute with cookie-based session persistence routes requests with the same cookie to the same backend",
+	Manifests:   []string{"tests/httproute-session-persistence-cookie.yaml"},
+	Features: []features.FeatureName{
+		features.SupportGateway,
+		features.SupportHTTPRoute,
+		features.SupportHTTPRouteSessionPersistenceCookie,
+	},
+	Test: func(t *testing.T, suite *suite.ConformanceTestSuite) {
+		const (
+			ns   = "gateway-conformance-infra"
+			path = "/session-persistence"
+		)
+		routeNN := types.NamespacedName{Name: "session-persistence-cookie", 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)
+
+		expected := http.ExpectedResponse{
+			Request: http.Request{
+				Path: path,
+			},
+			Response: http.Response{
+				StatusCode: 200,
+			},
+			Namespace: ns,
+		}
+
+		http.MakeRequestAndExpectEventuallyConsistentResponse(t, suite.RoundTripper, suite.TimeoutConfig, gwAddr, expected)
+
+		req := http.MakeRequest(t, &expected, gwAddr, "HTTP", "http")
+		initialPod := ""
+		for i := 0; i < 10; i++ {
+			cReq, cRes, err := suite.RoundTripper.CaptureRoundTrip(req)
+			if err != nil {
+				t.Fatalf("request %d with cookie failed: %v", i+1, err)
+			}
+			if err := http.CompareRoundTrip(t, &req, cReq, cRes, expected); err != nil {
+				t.Fatalf("request %d with cookie failed expectations: %v", i+1, err)
+			}
+
+			if i == 0 {
+				if cReq.Pod == "" {
+					t.Fatalf("expected pod to be set")
+				}
+				cookie, err := parseCookie(cRes.Headers)
+				if err != nil {
+					t.Fatalf("failed to parse session persistence cookie: %v", err)
+				}
+				t.Logf("session persistence cookie: %s=%s", cookie.Name, cookie.Value)
+				req.Headers["Cookie"] = []string{fmt.Sprintf("%s=%s", cookie.Name, cookie.Value)}
+				initialPod = cReq.Pod
+				continue
+			}
+			if cReq.Pod != initialPod {
+				t.Fatalf("expected session persistence to keep routing to pod %q, got %q", initialPod, cReq.Pod)
+			}
+		}
+	},
+}
+
+func parseCookie(headers map[string][]string) (*stdhttp.Cookie, error) {
+	parser := &stdhttp.Response{Header: stdhttp.Header(headers)}
+	cookies := parser.Cookies()
+	if len(cookies) == 0 {
+		return nil, fmt.Errorf("cookie not found: headers: %v", headers)
+	}
+	return cookies[0], nil
+}

conformance/tests/httproute-session-persistence-cookie.yaml

@@ -0,0 +1,22 @@
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: session-persistence-cookie
+  namespace: gateway-conformance-infra
+spec:
+  parentRefs:
+  - name: same-namespace
+  rules:
+  - matches:
+    - path:
+        type: PathPrefix
+        value: /session-persistence
+    sessionPersistence:
+      type: Cookie
+      cookieConfig:
+        lifetimeType: Session
+    backendRefs:
+    - name: infra-backend-v1
+      port: 8080
+    - name: infra-backend-v2
+      port: 8080

hack/implementations/envoy-gateway/README.md

@@ -37,10 +37,12 @@ EOF
 ## Step 4: Run a specific conformance test
 
 ```shell script
-go test -v ./conformance \
---run TestConformance/TLSRouteSimpleSameNamespace \
---gateway-class=envoy-gateway --supported-features=Gateway,TLSRoute \
---allow-crds-mismatch
+go test -v ../../../conformance \
+--run TestConformance/HTTPRouteSessionPersistenceCookie \
+--gateway-class=envoy-gateway \
+--supported-features=Gateway,HTTPRoute,HTTPRouteSessionPersistenceCookie \
+--allow-crds-mismatch \
+--cleanup-base-resources=false --debug
 ```
 
 ## (Optional) Step 4: Delete kind cluster

pkg/features/httproute.go

@@ -111,6 +111,9 @@ const (
 
 	// This option indicates support for HTTPRoute additional redirect status code 303 (extended conformance)
 	SupportHTTPRoute308RedirectStatusCode FeatureName = "HTTPRoute308RedirectStatusCode"
+
+	// This option indicates support for HTTPRoute cookie-based session persistence (extended conformance).
+	SupportHTTPRouteSessionPersistenceCookie FeatureName = "HTTPRouteSessionPersistenceCookie"
 )
 
 var (
@@ -229,6 +232,11 @@ var (
 		Name:    SupportHTTPRoute308RedirectStatusCode,
 		Channel: FeatureChannelStandard,
 	}
+	// HTTPRouteSessionPersistenceCookieFeature contains metadata for the SupportHTTPRouteSessionPersistenceCookie feature.
+	HTTPRouteSessionPersistenceCookieFeature = Feature{
+		Name:    SupportHTTPRouteSessionPersistenceCookie,
+		Channel: FeatureChannelExperimental,
+	}
 )
 
 // HTTPRouteExtendedFeatures includes all extended features for HTTPRoute
@@ -258,4 +266,5 @@ var HTTPRouteExtendedFeatures = sets.New(
 	HTTPRoute303RedirectStatusCodeFeature,
 	HTTPRoute307RedirectStatusCodeFeature,
 	HTTPRoute308RedirectStatusCodeFeature,
+	HTTPRouteSessionPersistenceCookieFeature,
 )