package middlewares import ( "context" "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 } rawReqPath := r.URL.Path r.URL.Path = r.URL.Path[len(prefix.Path):] if r.URL.RawPath != "" { r.URL.RawPath = r.URL.RawPath[len(prefix.Path):] } r = r.WithContext(context.WithValue(r.Context(), StripPrefixKey, rawReqPath)) r.Header.Add(ForwardedPrefixHeader, prefix.Path) r.RequestURI = ensureLeadingSlash(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 }