Fix regex with PathStrip

middlewares/stripPrefixRegex.go

@@ -0,0 +1,54 @@
+package middlewares
+
+import (
+	"net/http"
+
+	"github.com/containous/mux"
+	"github.com/containous/traefik/log"
+)
+
+// StripPrefixRegex is a middleware used to strip prefix from an URL request
+type StripPrefixRegex struct {
+	Handler http.Handler
+	router  *mux.Router
+}
+
+// NewStripPrefixRegex builds a new StripPrefixRegex given a handler and prefixes
+func NewStripPrefixRegex(handler http.Handler, prefixes []string) *StripPrefixRegex {
+	stripPrefix := StripPrefixRegex{Handler: handler, router: mux.NewRouter()}
+
+	for _, prefix := range prefixes {
+		stripPrefix.router.PathPrefix(prefix)
+	}
+
+	return &stripPrefix
+}
+
+func (s *StripPrefixRegex) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	var match mux.RouteMatch
+	if s.router.Match(r, &match) {
+		params := make([]string, 0, len(match.Vars)*2)
+		for key, val := range match.Vars {
+			params = append(params, key)
+			params = append(params, val)
+		}
+
+		prefix, err := match.Route.URL(params...)
+		if err != nil || len(prefix.Path) > len(r.URL.Path) {
+			log.Error("Error in stripPrefix middleware", err)
+			return
+		}
+
+		r.URL.Path = r.URL.Path[len(prefix.Path):]
+		r.Header[forwardedPrefixHeader] = []string{prefix.Path}
+		r.RequestURI = r.URL.RequestURI()
+		s.Handler.ServeHTTP(w, r)
+		return
+	}
+	http.NotFound(w, r)
+}
+
+// SetHandler sets handler
+func (s *StripPrefixRegex) SetHandler(Handler http.Handler) {
+	s.Handler = Handler
+}