feat: support rewrite annotation (#480)

docs/en/latest/concepts/annotations.md

@@ -59,3 +59,41 @@ Blocklist Source Range
 
 You can specify the denied client IP addresses or nets by the annotation `k8s.apisix.apache.org/blocklist-source-range`, multiple IP addresses or nets join together with `,`,
 for instance, `k8s.apisix.apache.org/blocklist-source-range: 127.0.0.1,172.17.0.0/16`. Default value is *empty*, which means the sources are not limited.
+
+Rewrite Target
+--------------
+
+You can rewrite requests by specifying the annotation `k8s.apisix.apache.org/rewrite-target` or `k8s.apisix.apache.org/rewrite-target-regex`.
+
+The annotation `k8s.apisix.apache.org/rewrite-target` controls where the request will be forwarded to.
+
+If you want to use regex and match groups, use annotation `k8s.apisix.apache.org/rewrite-target-regex` and `k8s.apisix.apache.org/rewrite-target-regex-template`. The first annotation contains the matching rule (regex), the second one contains the rewrite rule.
+
+Both annotations must be used together, otherwise they will be ignored.
+
+For example, we have an Ingress matches prefix path `/app`, and we set `k8s.apisix.apache.org/rewrite-target-regex` to `/app/(.*)` and set `k8s.apisix.apache.org/rewrite-target-regex-template` to `/$1`.
+
+```yaml
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  annotations:
+    kubernetes.io/ingress.class: apisix
+    k8s.apisix.apache.org/rewrite-target-regex: "/app/(.*)"
+    k8s.apisix.apache.org/rewrite-target-regex-template: "/$1"
+  name: ingress-v1
+spec:
+  rules:
+  - host: httpbin.org
+    http:
+      paths:
+      - path: /app
+        pathType: Prefix
+        backend:
+          service:
+            name: httpbin
+            port:
+              number: 80
+```
+
+With this Ingress, any requests with `/app` prefix will be forwarded to backend without the `/app/` part, e.g. request `/app/ip` will be forwarded to `/ip`.  

pkg/kube/translation/annotations.go

@@ -26,6 +26,7 @@ var (
 	_handlers = []annotations.Handler{
 		annotations.NewCorsHandler(),
 		annotations.NewIPRestrictionHandler(),
+		annotations.NewRewriteHandler(),
 	}
 )
 

pkg/kube/translation/annotations/rewrite.go

@@ -0,0 +1,58 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements.  See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You 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 (
+	"regexp"
+
+	apisixv1 "github.com/apache/apisix-ingress-controller/pkg/types/apisix/v1"
+)
+
+const (
+	_rewriteTarget              = "k8s.apisix.apache.org/rewrite-target"
+	_rewriteTargetRegex         = "k8s.apisix.apache.org/rewrite-target-regex"
+	_rewriteTargetRegexTemplate = "k8s.apisix.apache.org/rewrite-target-regex-template"
+)
+
+type rewrite struct{}
+
+// NewRewriteHandler creates a handler to convert
+// annotations about request rewrite control to APISIX proxy-rewrite plugin.
+func NewRewriteHandler() Handler {
+	return &rewrite{}
+}
+
+func (i *rewrite) PluginName() string {
+	return "proxy-rewrite"
+}
+
+func (i *rewrite) Handle(e Extractor) (interface{}, error) {
+	var plugin apisixv1.RewriteConfig
+	rewriteTarget := e.GetStringAnnotation(_rewriteTarget)
+	rewriteTargetRegex := e.GetStringAnnotation(_rewriteTargetRegex)
+	rewriteTemplate := e.GetStringAnnotation(_rewriteTargetRegexTemplate)
+	if rewriteTarget != "" || rewriteTargetRegex != "" || rewriteTemplate != "" {
+		plugin.RewriteTarget = rewriteTarget
+		if rewriteTargetRegex != "" && rewriteTemplate != "" {
+			_, err := regexp.Compile(rewriteTargetRegex)
+			if err != nil {
+				return nil, err
+			}
+			plugin.RewriteTargetRegex = []string{rewriteTargetRegex, rewriteTemplate}
+		}
+		return &plugin, nil
+	}
+	return nil, nil
+}

pkg/types/apisix/v1/plugin_types.go

@@ -48,3 +48,10 @@ type CorsConfig struct {
 	AllowMethods string `json:"allow_methods,omitempty"`
 	AllowHeaders string `json:"allow_headers,omitempty"`
 }
+
+// RewriteConfig is the rule config for proxy-rewrite plugin.
+// +k8s:deepcopy-gen=true
+type RewriteConfig struct {
+	RewriteTarget      string   `json:"uri,omitempty"`
+	RewriteTargetRegex []string `json:"regex_uri,omitempty"`
+}

test/e2e/annotations/rewrite.go

@@ -0,0 +1,215 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements.  See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You 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 (
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/onsi/ginkgo"
+	"github.com/stretchr/testify/assert"
+
+	"github.com/apache/apisix-ingress-controller/test/e2e/scaffold"
+)
+
+var _ = ginkgo.Describe("rewrite annotations", func() {
+	s := scaffold.NewDefaultScaffold()
+
+	ginkgo.It("enable in ingress networking/v1", func() {
+		backendSvc, backendPort := s.DefaultHTTPBackend()
+		ing := fmt.Sprintf(`
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  annotations:
+    kubernetes.io/ingress.class: apisix
+    k8s.apisix.apache.org/rewrite-target: "/ip"
+  name: ingress-v1
+spec:
+  rules:
+  - host: httpbin.org
+    http:
+      paths:
+      - path: /sample
+        pathType: Exact
+        backend:
+          service:
+            name: %s
+            port:
+              number: %d
+`, backendSvc, backendPort[0])
+		err := s.CreateResourceFromString(ing)
+		assert.Nil(ginkgo.GinkgoT(), err, "creating ingress")
+		time.Sleep(5 * time.Second)
+
+		_ = s.NewAPISIXClient().GET("/sample").WithHeader("Host", "httpbin.org").Expect().Status(http.StatusOK)
+		_ = s.NewAPISIXClient().GET("/ip").WithHeader("Host", "httpbin.org").Expect().Status(http.StatusNotFound)
+	})
+
+	ginkgo.It("enable in ingress networking/v1beta1", func() {
+		backendSvc, backendPort := s.DefaultHTTPBackend()
+		ing := fmt.Sprintf(`
+apiVersion: networking.k8s.io/v1beta1
+kind: Ingress
+metadata:
+  annotations:
+    kubernetes.io/ingress.class: apisix
+    k8s.apisix.apache.org/rewrite-target: "/ip"
+  name: ingress-v1beta1
+spec:
+  rules:
+  - host: httpbin.org
+    http:
+      paths:
+      - path: /sample
+        pathType: Exact
+        backend:
+          serviceName: %s
+          servicePort: %d
+`, backendSvc, backendPort[0])
+		err := s.CreateResourceFromString(ing)
+		assert.Nil(ginkgo.GinkgoT(), err, "creating ingress")
+		time.Sleep(5 * time.Second)
+
+		_ = s.NewAPISIXClient().GET("/sample").WithHeader("Host", "httpbin.org").Expect().Status(http.StatusOK)
+		_ = s.NewAPISIXClient().GET("/ip").WithHeader("Host", "httpbin.org").Expect().Status(http.StatusNotFound)
+	})
+
+	ginkgo.It("enable in ingress extensions/v1beta1", func() {
+		backendSvc, backendPort := s.DefaultHTTPBackend()
+		ing := fmt.Sprintf(`
+apiVersion: extensions/v1beta1
+kind: Ingress
+metadata:
+  annotations:
+    kubernetes.io/ingress.class: apisix
+    k8s.apisix.apache.org/rewrite-target: "/ip"
+  name: ingress-extensions-v1beta1
+spec:
+  rules:
+  - host: httpbin.org
+    http:
+      paths:
+      - path: /sample
+        pathType: Exact
+        backend:
+          serviceName: %s
+          servicePort: %d
+`, backendSvc, backendPort[0])
+		err := s.CreateResourceFromString(ing)
+		assert.Nil(ginkgo.GinkgoT(), err, "creating ingress")
+		time.Sleep(5 * time.Second)
+
+		_ = s.NewAPISIXClient().GET("/sample").WithHeader("Host", "httpbin.org").Expect().Status(http.StatusOK)
+		_ = s.NewAPISIXClient().GET("/ip").WithHeader("Host", "httpbin.org").Expect().Status(http.StatusNotFound)
+	})
+})
+
+var _ = ginkgo.Describe("rewrite regex annotations", func() {
+	s := scaffold.NewDefaultScaffold()
+
+	ginkgo.It("enable in ingress networking/v1", func() {
+		backendSvc, backendPort := s.DefaultHTTPBackend()
+		ing := fmt.Sprintf(`
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  annotations:
+    kubernetes.io/ingress.class: apisix
+    k8s.apisix.apache.org/rewrite-target-regex: "/sample/(.*)"
+    k8s.apisix.apache.org/rewrite-target-regex-template: "/$1"
+  name: ingress-v1
+spec:
+  rules:
+  - host: httpbin.org
+    http:
+      paths:
+      - path: /sample
+        pathType: Prefix
+        backend:
+          service:
+            name: %s
+            port:
+              number: %d
+`, backendSvc, backendPort[0])
+		err := s.CreateResourceFromString(ing)
+		assert.Nil(ginkgo.GinkgoT(), err, "creating ingress")
+		time.Sleep(5 * time.Second)
+
+		_ = s.NewAPISIXClient().GET("/sample/ip").WithHeader("Host", "httpbin.org").Expect().Status(http.StatusOK)
+		_ = s.NewAPISIXClient().GET("/sample/get").WithHeader("Host", "httpbin.org").Expect().Status(http.StatusOK)
+	})
+
+	ginkgo.It("enable in ingress networking/v1beta1", func() {
+		backendSvc, backendPort := s.DefaultHTTPBackend()
+		ing := fmt.Sprintf(`
+apiVersion: networking.k8s.io/v1beta1
+kind: Ingress
+metadata:
+  annotations:
+    kubernetes.io/ingress.class: apisix
+    k8s.apisix.apache.org/rewrite-target-regex: "/sample/(.*)"
+    k8s.apisix.apache.org/rewrite-target-regex-template: "/$1"
+  name: ingress-v1beta1
+spec:
+  rules:
+  - host: httpbin.org
+    http:
+      paths:
+      - path: /sample
+        pathType: Prefix
+        backend:
+          serviceName: %s
+          servicePort: %d
+`, backendSvc, backendPort[0])
+		err := s.CreateResourceFromString(ing)
+		assert.Nil(ginkgo.GinkgoT(), err, "creating ingress")
+		time.Sleep(5 * time.Second)
+
+		_ = s.NewAPISIXClient().GET("/sample/ip").WithHeader("Host", "httpbin.org").Expect().Status(http.StatusOK)
+		_ = s.NewAPISIXClient().GET("/sample/get").WithHeader("Host", "httpbin.org").Expect().Status(http.StatusOK)
+	})
+
+	ginkgo.It("enable in ingress extensions/v1beta1", func() {
+		backendSvc, backendPort := s.DefaultHTTPBackend()
+		ing := fmt.Sprintf(`
+apiVersion: extensions/v1beta1
+kind: Ingress
+metadata:
+  annotations:
+    kubernetes.io/ingress.class: apisix
+    k8s.apisix.apache.org/rewrite-target-regex: "/sample/(.*)"
+    k8s.apisix.apache.org/rewrite-target-regex-template: "/$1"
+  name: ingress-extensions-v1beta1
+spec:
+  rules:
+  - host: httpbin.org
+    http:
+      paths:
+      - path: /sample
+        pathType: Prefix
+        backend:
+          serviceName: %s
+          servicePort: %d
+`, backendSvc, backendPort[0])
+		err := s.CreateResourceFromString(ing)
+		assert.Nil(ginkgo.GinkgoT(), err, "creating ingress")
+		time.Sleep(5 * time.Second)
+
+		_ = s.NewAPISIXClient().GET("/sample/ip").WithHeader("Host", "httpbin.org").Expect().Status(http.StatusOK)
+		_ = s.NewAPISIXClient().GET("/sample/get").WithHeader("Host", "httpbin.org").Expect().Status(http.StatusOK)
+	})
+})