Allow http service to expose prefixes containing slashes (/) (cs3org#…

…3070)

changelog/unreleased/ext-http-service-prefix.md

@@ -0,0 +1,3 @@
+Enhancement: Allow http service to expose prefixes containing /
+
+https://github.com/cs3org/reva/pull/3070

pkg/rhttp/rhttp.go

@@ -25,14 +25,14 @@ import (
 	"net/http"
 	"path"
 	"sort"
+	"strings"
 	"time"
 
 	"github.com/cs3org/reva/internal/http/interceptors/appctx"
 	"github.com/cs3org/reva/internal/http/interceptors/auth"
 	"github.com/cs3org/reva/internal/http/interceptors/log"
 	"github.com/cs3org/reva/internal/http/interceptors/providerauthorizer"
 	"github.com/cs3org/reva/pkg/rhttp/global"
-	"github.com/cs3org/reva/pkg/rhttp/router"
 	rtrace "github.com/cs3org/reva/pkg/trace"
 	"github.com/mitchellh/mapstructure"
 	"github.com/pkg/errors"
@@ -234,25 +234,80 @@ func getUnprotected(prefix string, unprotected []string) []string {
 	return unprotected
 }
 
+// clean the url putting a slash (/) at the beginning if it does not have it
+// and removing the slashes at the end
+// if the url is "/", the output is ""
+func cleanURL(url string) string {
+	if len(url) > 0 {
+		if url[0] != '/' {
+			url = "/" + url
+		}
+		url = strings.TrimRight(url, "/")
+	}
+	return url
+}
+
+func urlHasPrefix(url, prefix string) bool {
+	url = cleanURL(url)
+	prefix = cleanURL(prefix)
+
+	partsURL := strings.Split(url, "/")
+	partsPrefix := strings.Split(prefix, "/")
+
+	if len(partsPrefix) > len(partsURL) {
+		return false
+	}
+
+	for i, p := range partsPrefix {
+		u := partsURL[i]
+		if p != u {
+			return false
+		}
+	}
+
+	return true
+}
+
+func (s *Server) getHandlerLongestCommongURL(url string) (http.Handler, string, bool) {
+	var match string
+
+	for k := range s.handlers {
+		if urlHasPrefix(url, k) && len(k) > len(match) {
+			match = k
+		}
+	}
+
+	h, ok := s.handlers[match]
+	return h, match, ok
+}
+
+func getSubURL(url, prefix string) string {
+	// pre cond: prefix is a prefix for url
+	// example: url = "/api/v0/", prefix = "/api", res = "/v0"
+	url = cleanURL(url)
+	prefix = cleanURL(prefix)
+
+	return url[len(prefix):]
+}
+
 func (s *Server) getHandler() (http.Handler, error) {
 	h := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		head, tail := router.ShiftPath(r.URL.Path)
-		if h, ok := s.handlers[head]; ok {
-			r.URL.Path = tail
-			s.log.Debug().Msgf("http routing: head=%s tail=%s svc=%s", head, r.URL.Path, head)
+		if h, ok := s.handlers[r.URL.Path]; ok {
+			s.log.Debug().Msgf("http routing: url=%s", r.URL.Path)
+			r.URL.Path = "/"
 			h.ServeHTTP(w, r)
 			return
 		}
 
-		// when a service is exposed at the root.
-		if h, ok := s.handlers[""]; ok {
-			r.URL.Path = "/" + head + tail
-			s.log.Debug().Msgf("http routing: head= tail=%s svc=root", r.URL.Path)
+		// find by longest common path
+		if h, url, ok := s.getHandlerLongestCommongURL(r.URL.Path); ok {
+			s.log.Debug().Msgf("http routing: url=%s", url)
+			r.URL.Path = getSubURL(r.URL.Path, url)
 			h.ServeHTTP(w, r)
 			return
 		}
 
-		s.log.Debug().Msgf("http routing: head=%s tail=%s svc=not-found", head, tail)
+		s.log.Debug().Msgf("http routing: url=%s svc=not-found", r.URL.Path)
 		w.WriteHeader(http.StatusNotFound)
 	})
 

pkg/rhttp/rhttp_test.go

@@ -0,0 +1,74 @@
+// Copyright 2018-2022 CERN
+//
+// Licensed 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.
+//
+// In applying this license, CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+package rhttp
+
+import "testing"
+
+func TestURLHasPrefix(t *testing.T) {
+	tests := map[string]struct {
+		url      string
+		prefix   string
+		expected bool
+	}{
+		"root": {
+			url:      "/",
+			prefix:   "/",
+			expected: true,
+		},
+		"suburl_root": {
+			url:      "/api/v0",
+			prefix:   "/",
+			expected: true,
+		},
+		"suburl_root_slash_end": {
+			url:      "/api/v0/",
+			prefix:   "/",
+			expected: true,
+		},
+		"suburl_root_no_slash": {
+			url:      "/api/v0",
+			prefix:   "",
+			expected: true,
+		},
+		"no_common_prefix": {
+			url:      "/api/v0/project",
+			prefix:   "/api/v0/p",
+			expected: false,
+		},
+		"long_url_prefix": {
+			url:      "/api/v0/project/test",
+			prefix:   "/api/v0",
+			expected: true,
+		},
+		"prefix_end_slash": {
+			url:      "/api/v0/project/test",
+			prefix:   "/api/v0/",
+			expected: true,
+		},
+	}
+
+	for name, test := range tests {
+		t.Run(name, func(t *testing.T) {
+			res := urlHasPrefix(test.url, test.prefix)
+			if res != test.expected {
+				t.Fatalf("%s got an unexpected result: %+v instead of %+v", t.Name(), res, test.expected)
+			}
+		})
+	}
+}