add brotli-min-length configuration option (#7854)

* add `brotli-min-length` configuration option

* add e2e tests for brotli

* include check for expected content type

* fix header and format

test/e2e/settings/brotli.go

@@ -0,0 +1,74 @@
+/*
+Copyright 2021 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 settings
+
+import (
+	"fmt"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"github.com/onsi/ginkgo"
+
+	"k8s.io/ingress-nginx/test/e2e/framework"
+)
+
+var _ = framework.IngressNginxDescribe("brotli", func() {
+	f := framework.NewDefaultFramework("brotli")
+
+	host := "brotli"
+
+	ginkgo.BeforeEach(func() {
+		f.NewHttpbinDeployment()
+	})
+
+	ginkgo.It("should only compress responses that meet the `brotli-min-length` condition", func() {
+		brotliMinLength := 24
+		contentEncoding := "application/octet-stream"
+		f.UpdateNginxConfigMapData("enable-brotli", "true")
+		f.UpdateNginxConfigMapData("brotli-types", contentEncoding)
+		f.UpdateNginxConfigMapData("brotli-min-length", strconv.Itoa(brotliMinLength))
+
+		f.EnsureIngress(framework.NewSingleIngress(host, "/", host, f.Namespace, framework.HTTPBinService, 80, nil))
+
+		f.WaitForNginxConfiguration(
+			func(server string) bool {
+				return strings.Contains(server, fmt.Sprintf("server_name %v", host)) &&
+					strings.Contains(server, "brotli on") &&
+					strings.Contains(server, fmt.Sprintf("brotli_types %v", contentEncoding)) &&
+					strings.Contains(server, fmt.Sprintf("brotli_min_length %d", brotliMinLength))
+			})
+
+		f.HTTPTestClient().
+			GET(fmt.Sprintf("/bytes/%d", brotliMinLength)).
+			WithHeader("Host", host).
+			WithHeader("Accept-Encoding", "br").
+			Expect().
+			Status(http.StatusOK).
+			ContentType(contentEncoding).
+			ContentEncoding("br")
+
+		f.HTTPTestClient().
+			GET(fmt.Sprintf("/bytes/%d", brotliMinLength-1)).
+			WithHeader("Host", host).
+			WithHeader("Accept-Encoding", "br").
+			Expect().
+			Status(http.StatusOK).
+			ContentType(contentEncoding).
+			ContentEncoding()
+	})
+})