Add option to sanitize annotation inputs (#7874)

* Add option to sanitize annotation inputs

* Fix e2e tests after string sanitization

* Add proxy_pass and serviceaccount as denied values

test/e2e/settings/badannotationvalues.go

@@ -0,0 +1,153 @@
+/*
+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"
+	"strings"
+
+	"github.com/onsi/ginkgo"
+
+	"k8s.io/ingress-nginx/test/e2e/framework"
+)
+
+var _ = framework.DescribeAnnotation("Bad annotation values", func() {
+	f := framework.NewDefaultFramework("bad-annotation")
+
+	ginkgo.BeforeEach(func() {
+		f.NewEchoDeployment()
+	})
+
+	ginkgo.It("should drop an ingress if there is an invalid character in some annotation", func() {
+		host := "invalid-value-test"
+
+		annotations := map[string]string{
+			"nginx.ingress.kubernetes.io/configuration-snippet": `
+			# abc { }`,
+		}
+
+		ing := framework.NewSingleIngress(host, "/", host, f.Namespace, framework.EchoService, 80, annotations)
+		f.UpdateNginxConfigMapData("allow-snippet-annotations", "true")
+		f.EnsureIngress(ing)
+
+		f.WaitForNginxServer(host,
+			func(server string) bool {
+				return !strings.Contains(server, fmt.Sprintf("server_name %s ;", host))
+			})
+
+		f.WaitForNginxServer(host,
+			func(server string) bool {
+				return !strings.Contains(server, "# abc { }")
+			})
+
+		f.HTTPTestClient().
+			GET("/").
+			WithHeader("Host", host).
+			Expect().
+			Status(http.StatusNotFound)
+	})
+
+	ginkgo.It("should drop an ingress if there is a forbidden word in some annotation", func() {
+		host := "forbidden-value-test"
+
+		annotations := map[string]string{
+			"nginx.ingress.kubernetes.io/configuration-snippet": `
+			  default_type text/plain;
+              content_by_lua_block {
+                ngx.say("Hello World")
+            }`,
+		}
+
+		ing := framework.NewSingleIngress(host, "/", host, f.Namespace, framework.EchoService, 80, annotations)
+		f.UpdateNginxConfigMapData("allow-snippet-annotations", "true")
+		// Sleep a while just to guarantee that the configmap is applied
+		framework.Sleep()
+		f.EnsureIngress(ing)
+
+		f.WaitForNginxServer(host,
+			func(server string) bool {
+				return !strings.Contains(server, fmt.Sprintf("server_name %s ;", host))
+			})
+
+		f.WaitForNginxServer(host,
+			func(server string) bool {
+				return !strings.Contains(server, `ngx.say("Hello World")`)
+			})
+
+		f.HTTPTestClient().
+			GET("/").
+			WithHeader("Host", host).
+			Expect().
+			Status(http.StatusNotFound)
+	})
+
+	ginkgo.It("should drop an ingress if there is a custom blocklist config in place and allow others to pass", func() {
+		host := "custom-forbidden-value-test"
+
+		annotations := map[string]string{
+			"nginx.ingress.kubernetes.io/configuration-snippet": `
+			# something_forbidden`,
+		}
+
+		hostValid := "custom-allowed-value-test"
+		annotationsValid := map[string]string{
+			"nginx.ingress.kubernetes.io/configuration-snippet": `
+			# bla_by_lua`,
+		}
+
+		ing := framework.NewSingleIngress(host, "/", host, f.Namespace, framework.EchoService, 80, annotations)
+		ingValid := framework.NewSingleIngress(hostValid, "/", hostValid, f.Namespace, framework.EchoService, 80, annotationsValid)
+		f.UpdateNginxConfigMapData("annotation-value-word-blocklist", "something_forbidden,otherthing_forbidden")
+		// Sleep a while just to guarantee that the configmap is applied
+		framework.Sleep()
+		f.EnsureIngress(ing)
+		f.EnsureIngress(ingValid)
+
+		f.WaitForNginxServer(host,
+			func(server string) bool {
+				return !strings.Contains(server, fmt.Sprintf("server_name %s ;", host))
+			})
+
+		f.WaitForNginxServer(hostValid,
+			func(server string) bool {
+				return strings.Contains(server, fmt.Sprintf("server_name %s ;", hostValid))
+			})
+
+		f.WaitForNginxServer(host,
+			func(server string) bool {
+				return !strings.Contains(server, "# something_forbidden")
+			})
+
+		f.WaitForNginxServer(hostValid,
+			func(server string) bool {
+				return strings.Contains(server, "# bla_by_lua")
+			})
+
+		f.HTTPTestClient().
+			GET("/").
+			WithHeader("Host", host).
+			Expect().
+			Status(http.StatusNotFound)
+
+		f.HTTPTestClient().
+			GET("/").
+			WithHeader("Host", hostValid).
+			Expect().
+			Status(http.StatusOK)
+	})
+})