e2e: add weighted backend (#2863)

* e2e: add backend weighted

Signed-off-by: ShyunnY <[email protected]>

* fix: Fix weight calculation issue and use AlmostEqual func

Signed-off-by: ShyunnY <[email protected]>

* fix: add additional comments

Signed-off-by: ShyunnY <[email protected]>

---------

Signed-off-by: ShyunnY <[email protected]>
Co-authored-by: Xunzhuo <[email protected]>

test/e2e/testdata/weight-backend-completing-rollout.yaml

@@ -0,0 +1,20 @@
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: weight-complete-rollout-http-route
+  namespace: gateway-conformance-infra
+spec:
+  parentRefs:
+    - name: same-namespace
+  rules:
+    - matches:
+        - path:
+            type: PathPrefix
+            value: /
+      backendRefs:
+        - name: infra-backend-v1
+          port: 8080
+          weight: 10
+        - name: infra-backend-v2
+          port: 8080
+          weight: 0

test/e2e/testdata/weighted-backend-all-equal.yaml

@@ -0,0 +1,20 @@
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: weight-equal-http-route
+  namespace: gateway-conformance-infra
+spec:
+  parentRefs:
+    - name: same-namespace
+  rules:
+    - matches:
+        - path:
+            type: PathPrefix
+            value: /
+      backendRefs:
+        - name: infra-backend-v1
+          port: 8080
+          weight: 1
+        - name: infra-backend-v2
+          port: 8080
+          weight: 1

test/e2e/testdata/weighted-backend-bluegreen.yaml

@@ -0,0 +1,20 @@
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: weight-bluegreen-http-route
+  namespace: gateway-conformance-infra
+spec:
+  parentRefs:
+    - name: same-namespace
+  rules:
+    - matches:
+        - path:
+            type: PathPrefix
+            value: /
+      backendRefs:
+        - name: infra-backend-v1
+          port: 8080
+          weight: 9
+        - name: infra-backend-v2
+          port: 8080
+          weight: 1

test/e2e/tests/utils.go

@@ -118,3 +118,14 @@ func BackendTrafficPolicyMustBeAccepted(t *testing.T, client client.Client, poli
 
 	require.NoErrorf(t, waitErr, "error waiting for BackendTrafficPolicy to be accepted")
 }
+
+// AlmostEquals We use a solution similar to istio:
+// Given an offset, calculate whether the actual value is within the offset of the expected value
+func AlmostEquals(actual, expect, offset int) bool {
+	upper := actual + offset
+	lower := actual - offset
+	if expect < lower || expect > upper {
+		return false
+	}
+	return true
+}

test/e2e/tests/weighted_backend.go

@@ -0,0 +1,234 @@
+// Copyright Envoy Gateway Authors
+// SPDX-License-Identifier: Apache-2.0
+// The full text of the Apache license is available in the LICENSE file at
+// the root of the repo.
+
+//go:build e2e
+// +build e2e
+
+package tests
+
+import (
+	"fmt"
+	"regexp"
+	"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"
+)
+
+func init() {
+	ConformanceTests = append(ConformanceTests, WeightEqualTest, WeightBlueGreenTest, WeightCompleteRolloutTest)
+}
+
+const sendRequest = 50
+
+var WeightEqualTest = suite.ConformanceTest{
+	ShortName:   "WeightEqualBackend",
+	Description: "Resource with Weight Backend enabled, and use the all backend weight is equal",
+	Manifests:   []string{"testdata/weighted-backend-all-equal.yaml"},
+	Test: func(t *testing.T, suite *suite.ConformanceTestSuite) {
+		t.Run("all backends receive the same weight of traffic", func(t *testing.T) {
+			ns := "gateway-conformance-infra"
+			weightEqualRoute := types.NamespacedName{Name: "weight-equal-http-route", Namespace: ns}
+			gwNN := types.NamespacedName{Name: "same-namespace", Namespace: ns}
+			gwAddr := kubernetes.GatewayAndHTTPRoutesMustBeAccepted(t, suite.Client, suite.TimeoutConfig,
+				suite.ControllerName,
+				kubernetes.NewGatewayRef(gwNN), weightEqualRoute)
+
+			expectedResponse := http.ExpectedResponse{
+				Request: http.Request{
+					Path: "/",
+				},
+				Response: http.Response{
+					StatusCode: 200,
+				},
+				Namespace: ns,
+			}
+			req := http.MakeRequest(t, &expectedResponse, gwAddr, "HTTP", "http")
+
+			// Since we only route to pods with "infra-backend-v 1" and "infra-backend-v 2" prefixes
+			// So here we use fixed weight values
+			expected := map[string]int{
+				"infra-backend-v1": sendRequest * .5,
+				"infra-backend-v2": sendRequest * .5,
+			}
+			weightMap := make(map[string]int)
+			for i := 0; i < sendRequest; i++ {
+				cReq, cResp, err := suite.RoundTripper.CaptureRoundTrip(req)
+				if err != nil {
+					t.Errorf("failed to get expected response: %v", err)
+				}
+
+				if err := http.CompareRequest(t, &req, cReq, cResp, expectedResponse); err != nil {
+					t.Errorf("failed to compare request and response: %v", err)
+				}
+
+				podName := cReq.Pod
+				if len(podName) == 0 {
+					// it shouldn't be missing here
+					t.Errorf("failed to get pod header in response: %v", err)
+
+				} else {
+					// all we need is the pod Name prefix
+					podNamePrefix := ExtractPodNamePrefix(podName)
+					weightMap[podNamePrefix]++
+				}
+			}
+
+			// We iterate over the actual traffic Map with podNamePrefix as the key to get the actual traffic.
+			// Given an offset of 3, we expect the expected traffic to be within the actual traffic [actual-3,actual+3] interval.
+			for prefix, actual := range weightMap {
+				expect := expected[prefix]
+				if !AlmostEquals(actual, expect, 3) {
+					t.Errorf("The actual traffic weights are not consistent with the expected routing weights")
+				}
+			}
+		})
+	},
+}
+
+var WeightBlueGreenTest = suite.ConformanceTest{
+	ShortName:   "WeightBlueGreenBackend",
+	Description: "Resource with Weight Backend enabled, and use the blue-green policy weight setting",
+	Manifests:   []string{"testdata/weighted-backend-bluegreen.yaml"},
+	Test: func(t *testing.T, suite *suite.ConformanceTestSuite) {
+		t.Run("all backends receive the blue green weight of traffic", func(t *testing.T) {
+			ns := "gateway-conformance-infra"
+			weightEqualRoute := types.NamespacedName{Name: "weight-bluegreen-http-route", Namespace: ns}
+			gwNN := types.NamespacedName{Name: "same-namespace", Namespace: ns}
+			gwAddr := kubernetes.GatewayAndHTTPRoutesMustBeAccepted(t, suite.Client, suite.TimeoutConfig,
+				suite.ControllerName,
+				kubernetes.NewGatewayRef(gwNN), weightEqualRoute)
+
+			expectedResponse := http.ExpectedResponse{
+				Request: http.Request{
+					Path: "/",
+				},
+				Response: http.Response{
+					StatusCode: 200,
+				},
+				Namespace: ns,
+			}
+			req := http.MakeRequest(t, &expectedResponse, gwAddr, "HTTP", "http")
+
+			// Since we only route to pods with "infra-backend-v 1" and "infra-backend-v 2" prefixes
+			// So here we use fixed weight values
+			expected := map[string]int{
+				"infra-backend-v1": sendRequest * .9,
+				"infra-backend-v2": sendRequest * .1,
+			}
+			weightMap := make(map[string]int)
+			for i := 0; i < sendRequest; i++ {
+				cReq, cResp, err := suite.RoundTripper.CaptureRoundTrip(req)
+				if err != nil {
+					t.Errorf("failed to get expected response: %v", err)
+				}
+
+				if err := http.CompareRequest(t, &req, cReq, cResp, expectedResponse); err != nil {
+					t.Errorf("failed to compare request and response: %v", err)
+				}
+
+				podName := cReq.Pod
+				if len(podName) == 0 {
+					// it shouldn't be missing here
+					t.Errorf("failed to get pod header in response: %v", err)
+
+				} else {
+					// all we need is the pod Name prefix
+					podNamePrefix := ExtractPodNamePrefix(podName)
+					weightMap[podNamePrefix]++
+				}
+			}
+
+			// We iterate over the actual traffic Map with podNamePrefix as the key to get the actual traffic.
+			// Given an offset of 3, we expect the expected traffic to be within the actual traffic [actual-3,actual+3] interval.
+			for prefix, actual := range weightMap {
+				expect := expected[prefix]
+				if !AlmostEquals(actual, expect, 3) {
+					t.Errorf("The actual traffic weights are not consistent with the expected routing weights")
+				}
+			}
+		})
+	},
+}
+
+var WeightCompleteRolloutTest = suite.ConformanceTest{
+	ShortName:   "WeightCompleteRollout",
+	Description: "Resource with Weight Backend enabled, and use the completing rollout policy weight setting",
+	Manifests:   []string{"testdata/weight-backend-completing-rollout.yaml"},
+	Test: func(t *testing.T, suite *suite.ConformanceTestSuite) {
+		t.Run("all backends receive the complete rollout weight of traffic", func(t *testing.T) {
+			ns := "gateway-conformance-infra"
+			weightEqualRoute := types.NamespacedName{Name: "weight-complete-rollout-http-route", Namespace: ns}
+			gwNN := types.NamespacedName{Name: "same-namespace", Namespace: ns}
+			gwAddr := kubernetes.GatewayAndHTTPRoutesMustBeAccepted(t, suite.Client, suite.TimeoutConfig,
+				suite.ControllerName,
+				kubernetes.NewGatewayRef(gwNN), weightEqualRoute)
+
+			expectedResponse := http.ExpectedResponse{
+				Request: http.Request{
+					Path: "/",
+				},
+				Response: http.Response{
+					StatusCode: 200,
+				},
+				Namespace: ns,
+			}
+			req := http.MakeRequest(t, &expectedResponse, gwAddr, "HTTP", "http")
+
+			// Since we only route to pods with "infra-backend-v 1" and "infra-backend-v 2" prefixes
+			// So here we use fixed weight values
+			expected := map[string]int{
+				"infra-backend-v1": sendRequest * 1,
+				"infra-backend-v2": sendRequest * 0,
+			}
+			weightMap := make(map[string]int)
+			for i := 0; i < sendRequest; i++ {
+				cReq, cResp, err := suite.RoundTripper.CaptureRoundTrip(req)
+				if err != nil {
+					t.Errorf("failed to get expected response: %v", err)
+				}
+
+				if err := http.CompareRequest(t, &req, cReq, cResp, expectedResponse); err != nil {
+					t.Errorf("failed to compare request and response: %v", err)
+				}
+
+				podName := cReq.Pod
+				if len(podName) == 0 {
+					// it shouldn't be missing here
+					t.Errorf("failed to get pod header in response: %v", err)
+
+				} else {
+					// all we need is the pod Name prefix
+					podNamePrefix := ExtractPodNamePrefix(podName)
+					weightMap[podNamePrefix]++
+				}
+			}
+
+			// We iterate over the actual traffic Map with podNamePrefix as the key to get the actual traffic.
+			// Given an offset of 3, we expect the expected traffic to be within the actual traffic [actual-3,actual+3] interval.
+			for prefix, actual := range weightMap {
+				expect := expected[prefix]
+				if !AlmostEquals(actual, expect, 3) {
+					t.Errorf("The actual traffic weights are not consistent with the expected routing weights")
+				}
+			}
+		})
+	},
+}
+
+// ExtractPodNamePrefix Extract the Pod Name prefix
+func ExtractPodNamePrefix(podName string) string {
+
+	pattern := regexp.MustCompile(`infra-backend-(.+?)-`)
+	match := pattern.FindStringSubmatch(podName)
+	if len(match) > 1 {
+		version := match[1]
+		return fmt.Sprintf("infra-backend-%s", version)
+	}
+
+	return podName
+}