Lua: Fix limit_except returning 503.

rootfs/etc/nginx/lua/balancer.lua

@@ -277,6 +277,11 @@ local function get_balancer()
 
   local backend_name = ngx.var.proxy_upstream_name
 
+  if backend_name == '-' then
+    ngx.status = ngx.HTTP_FORBIDDEN
+    return ngx.exit(ngx.status)                                                     
+  end
+
   local balancer = balancers[backend_name]
   if not balancer then
     return nil

test/e2e/annotations/limitexcept.go

@@ -0,0 +1,83 @@
+/*
+Copyright 2024 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"
+	"strings"
+
+	"github.com/onsi/ginkgo/v2"
+
+	"k8s.io/ingress-nginx/test/e2e/framework"
+)
+
+var _ = framework.DescribeAnnotation("limit-except", func() {
+	f := framework.NewDefaultFramework("limitexcept")
+
+	ginkgo.BeforeEach(func() {
+		f.NewEchoDeployment()
+	})
+
+	ginkgo.It("should return 403 when the request is not allowed", func() {
+		host := "foo.com"
+
+        annotations := map[string]string{
+            "nginx.ingress.kubernetes.io/server-snippet": `
+                location = / {
+                    return 403;
+                }`,
+            "nginx.ingress.kubernetes.io/configuration-snippet": `
+                limit_except GET {
+                    deny all;
+                }`,
+        }
+
+        ing := framework.NewSingleIngress(host, "/foo", host, f.Namespace, framework.EchoService, 80, annotations)
+		f.EnsureIngress(ing)
+
+        f.WaitForNginxServer(host,
+			func(server string) bool {
+				return strings.Contains(server, `location = / { return 403; }`) &&
+					strings.Contains(server, `limit_except GET { deny all; }`)
+			})
+
+		ginkgo.By("sending request to foo.com")
+		f.HTTPTestClient().
+		    POST("/").
+			WithHeader("Host", host).
+			Expect().
+			Status(http.StatusForbidden)
+
+        f.HTTPTestClient().
+			GET("/").
+			WithHeader("Host", host).
+			Expect().
+			Status(http.StatusForbidden)
+
+        f.HTTPTestClient().
+		    POST("/foo").
+			WithHeader("Host", host).
+			Expect().
+			Status(http.StatusForbidden)
+
+        f.HTTPTestClient().
+			GET("/foo").
+			WithHeader("Host", host).
+			Expect().
+			Status(http.StatusOK)
+	})
+})