Exclude socket metrics (#9770)

* exclude creation and exporting of socket metrics via flag

* make exclude metric naming more consistent

* fix connect time metric update

* add documentation

* e2e test

* improve creation of metric mapping

test/e2e/e2e.go

@@ -40,6 +40,7 @@ import (
 	_ "k8s.io/ingress-nginx/test/e2e/leaks"
 	_ "k8s.io/ingress-nginx/test/e2e/loadbalance"
 	_ "k8s.io/ingress-nginx/test/e2e/lua"
+	_ "k8s.io/ingress-nginx/test/e2e/metrics"
 	_ "k8s.io/ingress-nginx/test/e2e/nginx"
 	_ "k8s.io/ingress-nginx/test/e2e/security"
 	_ "k8s.io/ingress-nginx/test/e2e/servicebackend"

test/e2e/metrics/metrics.go

@@ -0,0 +1,94 @@
+/*
+Copyright 2023 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 defaultbackend
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/onsi/ginkgo/v2"
+	"github.com/stretchr/testify/assert"
+	appsv1 "k8s.io/api/apps/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
+	"k8s.io/ingress-nginx/test/e2e/framework"
+)
+
+const waitForMetrics = 2 * time.Second
+
+var _ = framework.IngressNginxDescribe("[metrics] exported prometheus metrics", func() {
+	f := framework.NewDefaultFramework("metrics")
+	host := "foo.com"
+
+	ginkgo.BeforeEach(func() {
+		f.NewEchoDeployment()
+		f.EnsureIngress(framework.NewSingleIngress(host, "/", host, f.Namespace, framework.EchoService, 80, nil))
+		f.WaitForNginxServer(host,
+			func(server string) bool {
+				return strings.Contains(server, fmt.Sprintf("server_name %s ;", host)) &&
+					strings.Contains(server, "proxy_pass http://upstream_balancer;")
+			})
+	})
+
+	ginkgo.It("exclude socket request metrics are absent", func() {
+		err := f.UpdateIngressControllerDeployment(func(deployment *appsv1.Deployment) error {
+			args := deployment.Spec.Template.Spec.Containers[0].Args
+			args = append(args, "--exclude-socket-metrics=nginx_ingress_controller_request_size,nginx_ingress_controller_header_duration_seconds")
+			deployment.Spec.Template.Spec.Containers[0].Args = args
+			_, err := f.KubeClientSet.AppsV1().Deployments(f.Namespace).Update(context.TODO(), deployment, metav1.UpdateOptions{})
+			return err
+		})
+		assert.Nil(ginkgo.GinkgoT(), err, "updating deployment")
+
+		f.HTTPTestClient().
+			GET("/").
+			WithHeader("Host", host).
+			Expect().
+			Status(http.StatusOK)
+		time.Sleep(waitForMetrics)
+
+		ip := f.GetNginxPodIP()
+		mf, err := f.GetMetric("nginx_ingress_controller_request_size", ip)
+		assert.ErrorContains(ginkgo.GinkgoT(), err, "nginx_ingress_controller_request_size")
+		assert.Nil(ginkgo.GinkgoT(), mf)
+	})
+	ginkgo.It("exclude socket request metrics are present", func() {
+		err := f.UpdateIngressControllerDeployment(func(deployment *appsv1.Deployment) error {
+			args := deployment.Spec.Template.Spec.Containers[0].Args
+			args = append(args, "--exclude-socket-metrics=non_existing_metric_does_not_affect_existing_metrics")
+			deployment.Spec.Template.Spec.Containers[0].Args = args
+			_, err := f.KubeClientSet.AppsV1().Deployments(f.Namespace).Update(context.TODO(), deployment, metav1.UpdateOptions{})
+			return err
+		})
+		assert.Nil(ginkgo.GinkgoT(), err, "updating deployment")
+
+		f.HTTPTestClient().
+			GET("/").
+			WithHeader("Host", host).
+			Expect().
+			Status(http.StatusOK)
+		time.Sleep(waitForMetrics)
+
+		ip := f.GetNginxPodIP()
+		mf, err := f.GetMetric("nginx_ingress_controller_request_size", ip)
+		assert.Nil(ginkgo.GinkgoT(), err)
+		assert.NotNil(ginkgo.GinkgoT(), mf)
+	})
+})