Allow preservation of trailing slashes on TLS redirects via annotation. (#7144)

* allow retaining a trailing slash in a TLS redirect via annotation.

Signed-off-by: mamiller <mamiller@rosettastone.com>

* requested changes

* gofmt

test/e2e/annotations/preservetrailingslash.go

@@ -0,0 +1,53 @@
+/*
+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 annotations
+
+import (
+	"net/http"
+
+	"github.com/onsi/ginkgo"
+
+	"k8s.io/ingress-nginx/test/e2e/framework"
+)
+
+var _ = framework.DescribeAnnotation("preserve-trailing-slash", func() {
+	f := framework.NewDefaultFramework("preservetrailingslash")
+
+	ginkgo.BeforeEach(func() {
+		f.NewEchoDeployment()
+	})
+
+	ginkgo.It("should allow preservation of trailing slashes", func() {
+		host := "forcesslredirect.bar.com"
+		tlsHosts := []string{host}
+
+		annotations := map[string]string{
+			"nginx.ingress.kubernetes.io/ssl-redirect":            "true",
+			"nginx.ingress.kubernetes.io/preserve-trailing-slash": "true",
+		}
+
+		ing := framework.NewSingleIngressWithTLS(host, "/", host, tlsHosts, f.Namespace, framework.EchoService, 80, annotations)
+		f.EnsureIngress(ing)
+
+		f.HTTPTestClient().
+			GET("/").
+			WithHeader("Host", host).
+			Expect().
+			Status(http.StatusPermanentRedirect).
+			Header("Location").Equal("https://forcesslredirect.bar.com/")
+	})
+})