added path replacement rule

middlewares/replace_path_test.go

@@ -0,0 +1,44 @@
+package middlewares_test
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/containous/traefik/middlewares"
+)
+
+func TestReplacePath(t *testing.T) {
+	const replacementPath = "/replacement-path"
+
+	paths := []string{
+		"/example",
+		"/some/really/long/path",
+	}
+
+	for _, path := range paths {
+		t.Run(path, func(t *testing.T) {
+			var newPath, oldPath string
+			handler := &middlewares.ReplacePath{
+				Path: replacementPath,
+				Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+					newPath = r.URL.Path
+					oldPath = r.Header.Get("X-Replaced-Path")
+				}),
+			}
+
+			req, err := http.NewRequest("GET", "http://localhost"+path, nil)
+			if err != nil {
+				t.Error(err)
+			}
+
+			handler.ServeHTTP(nil, req)
+			if newPath != replacementPath {
+				t.Fatalf("new path should be '%s'", replacementPath)
+			}
+
+			if oldPath != path {
+				t.Fatalf("old path should be '%s'", path)
+			}
+		})
+	}
+}