fix plugins (TykTechnologies#2923)

Fixes TykTechnologies#2922 

In 2.8.x URL Rewrite/Method transform middleware directly modified http.Request object.
This behavior was changed in 2.9.x(https://github.com/TykTechnologies/tyk/pull/2301/files) 
http.Request is now transformed at the end of middleware chain. Because of this Post hook did not received modified values.

Fixed the code by passing URLRewrite/Method Transform info to Post hook of the plugin.

coprocess/python/coprocess_python_test.go

@@ -11,6 +11,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/TykTechnologies/tyk/apidef"
 	"github.com/TykTechnologies/tyk/config"
 	"github.com/TykTechnologies/tyk/gateway"
 	"github.com/TykTechnologies/tyk/test"
@@ -98,6 +99,41 @@ def MyPostHook(request, session, spec):
 `,
 }
 
+var pythonPostRequestTransform = map[string]string{
+	"manifest.json": `
+		{
+		    "file_list": [
+		        "middleware.py"
+		    ],
+		    "custom_middleware": {
+		        "driver": "python",
+		        "post": [{
+		            "name": "MyPostHook"
+		        }]
+		    }
+		}
+	`,
+	"middleware.py": `
+from tyk.decorators import *
+from gateway import TykGateway as tyk
+import json
+
+@Hook
+def MyPostHook(request, session, spec):
+	
+	
+	if request.object.url == "/test2":
+		if request.object.method != "POST":
+			request.object.return_overrides.response_code = 500
+			request.object.return_overrides.response_error = "'invalid method type'"
+			return request, session
+		request.object.url = "tyk://test-api-2/newpath"
+		request.object.method = "GET"
+
+	return request , session
+`,
+}
+
 var pythonBundleWithPreHook = map[string]string{
 	"manifest.json": `
 		{
@@ -182,6 +218,7 @@ func TestPythonBundles(t *testing.T) {
 	postHookBundle := gateway.RegisterBundle("python_with_post_hook", pythonBundleWithPostHook)
 	preHookBundle := gateway.RegisterBundle("python_with_pre_hook", pythonBundleWithPreHook)
 	responseHookBundle := gateway.RegisterBundle("python_with_response_hook", pythonBundleWithResponseHook)
+	postRequestTransformHookBundle := gateway.RegisterBundle("python_post_with_request_transform_hook", pythonPostRequestTransform)
 
 	t.Run("Single-file bundle with authentication hook", func(t *testing.T) {
 		gateway.BuildAndLoadAPI(func(spec *gateway.APISpec) {
@@ -295,4 +332,45 @@ func TestPythonBundles(t *testing.T) {
 			{Path: "/test-api-2/", Code: http.StatusOK, Data: "{}", Headers: map[string]string{"Content-Type": "application/json"}},
 		}...)
 	})
+
+	t.Run("python post hook with url rewrite and method transform", func(t *testing.T) {
+		gateway.BuildAndLoadAPI(func(spec *gateway.APISpec) {
+			spec.Proxy.ListenPath = "/test-api-1/"
+			spec.UseKeylessAccess = true
+			spec.EnableCoProcessAuth = false
+			spec.CustomMiddlewareBundle = postRequestTransformHookBundle
+
+			v1 := spec.VersionData.Versions["v1"]
+			v1.UseExtendedPaths = true
+			v1.ExtendedPaths.URLRewrite = []apidef.URLRewriteMeta{{
+				Path:         "/get",
+				Method:       http.MethodGet,
+				MatchPattern: "/get",
+				RewriteTo:    "/test2",
+			}}
+
+			v1.ExtendedPaths.MethodTransforms = []apidef.MethodTransformMeta{{
+				Path:     "/get",
+				Method:   http.MethodGet,
+				ToMethod: http.MethodPost,
+			}}
+
+			spec.VersionData.Versions["v1"] = v1
+
+		}, func(spec *gateway.APISpec) {
+			spec.Name = "test-api-2"
+			spec.Proxy.ListenPath = "/test-api-2/"
+			spec.UseKeylessAccess = true
+			spec.EnableCoProcessAuth = false
+			spec.UseKeylessAccess = true
+		})
+
+		time.Sleep(1 * time.Second)
+
+		ts.Run(t, []test.TestCase{
+			{Path: "/test-api-1/get", Code: http.StatusOK, BodyMatch: "newpath"},
+			{Path: "/test-api-1/get", Code: http.StatusOK, BodyMatch: "GET"},
+			{Path: "/test-api-1/post", Code: http.StatusOK, BodyNotMatch: "newpath"},
+		}...)
+	})
 }

gateway/coprocess.go

@@ -172,11 +172,13 @@ func (c *CoProcessor) BuildObject(req *http.Request, res *http.Response) (*copro
 }
 
 // ObjectPostProcess does CoProcessObject post-processing (adding/removing headers or params, etc.).
-func (c *CoProcessor) ObjectPostProcess(object *coprocess.Object, r *http.Request) (err error) {
+func (c *CoProcessor) ObjectPostProcess(object *coprocess.Object, r *http.Request, origURL string, origMethod string) (err error) {
 	r.ContentLength = int64(len(object.Request.RawBody))
 	r.Body = ioutil.NopCloser(bytes.NewReader(object.Request.RawBody))
 	nopCloseRequestBody(r)
 
+	logger := c.Middleware.Logger()
+
 	for _, dh := range object.Request.DeleteHeaders {
 		r.Header.Del(dh)
 	}
@@ -194,11 +196,34 @@ func (c *CoProcessor) ObjectPostProcess(object *coprocess.Object, r *http.Reques
 		values.Set(p, v)
 	}
 
-	r.URL, err = url.ParseRequestURI(object.Request.Url)
+	parsedURL, err := url.ParseRequestURI(object.Request.Url)
 	if err != nil {
+		logger.Error(err)
 		return
 	}
+
+	rewriteURL := ctxGetURLRewriteTarget(r)
+	if rewriteURL != nil {
+		ctxSetURLRewriteTarget(r, parsedURL)
+		r.URL, err = url.ParseRequestURI(origURL)
+		if err != nil {
+			logger.Error(err)
+			return
+		}
+	} else {
+		r.URL = parsedURL
+	}
+
+	transformMethod := ctxGetTransformRequestMethod(r)
+	if transformMethod != "" {
+		ctxSetTransformRequestMethod(r, object.Request.Method)
+		r.Method = origMethod
+	} else {
+		r.Method = object.Request.Method
+	}
+
 	r.URL.RawQuery = values.Encode()
+
 	return
 }
 
@@ -300,6 +325,19 @@ func (m *CoProcessMiddleware) ProcessRequest(w http.ResponseWriter, r *http.Requ
 		return errors.New("Middleware error"), 500
 	}
 
+	var origURL string
+	if rewriteUrl := ctxGetURLRewriteTarget(r); rewriteUrl != nil {
+		origURL = object.Request.Url
+		object.Request.Url = rewriteUrl.String()
+		object.Request.RequestUri = rewriteUrl.RequestURI()
+	}
+
+	var origMethod string
+	if transformMethod := ctxGetTransformRequestMethod(r); transformMethod != "" {
+		origMethod = r.Method
+		object.Request.Method = transformMethod
+	}
+
 	t1 := time.Now()
 	returnObject, err := coProcessor.Dispatch(object)
 	ms := DurationToMillisecond(time.Since(t1))
@@ -315,7 +353,7 @@ func (m *CoProcessMiddleware) ProcessRequest(w http.ResponseWriter, r *http.Requ
 
 	m.logger.WithField("ms", ms).Debug("gRPC request processing took")
 
-	err = coProcessor.ObjectPostProcess(returnObject, r)
+	err = coProcessor.ObjectPostProcess(returnObject, r, origURL, origMethod)
 	if err != nil {
 		// Restore original URL object so that it can be used by ErrorHandler:
 		r.URL = originalURL

gateway/server.go

@@ -151,7 +151,7 @@ func getApisForOauthClientId(oauthClientId string) []string {
 
 	//generate a copy only with ids so we do not attempt to lock twice
 	apisMu.RLock()
-	for apiId, _ := range apisByID {
+	for apiId := range apisByID {
 		apisIdsCopy = append(apisIdsCopy, apiId)
 	}
 	apisMu.RUnlock()