Refactored file server to return errors

server/fileserver.go

@@ -2,9 +2,11 @@ package server
 
 import (
 	"net/http"
+	"os"
 	"path"
 	"strings"
 
+	"github.com/mholt/caddy/middleware"
 	"github.com/mholt/caddy/middleware/browse"
 )
 
@@ -16,7 +18,7 @@ import (
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
-func FileServer(root http.FileSystem) http.Handler {
+func FileServer(root http.FileSystem) middleware.Handler {
 	return &fileHandler{root}
 }
 
@@ -24,30 +26,32 @@ type fileHandler struct {
 	root http.FileSystem
 }
 
-func (f *fileHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+func (f *fileHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error) {
 	upath := r.URL.Path
 	if !strings.HasPrefix(upath, "/") {
 		upath = "/" + upath
 		r.URL.Path = upath
 	}
-	serveFile(w, r, f.root, path.Clean(upath), true)
+	return serveFile(w, r, f.root, path.Clean(upath))
 }
 
 // name is '/'-separated, not filepath.Separator.
-func serveFile(w http.ResponseWriter, r *http.Request, fs http.FileSystem, name string, redirect bool) {
+func serveFile(w http.ResponseWriter, r *http.Request, fs http.FileSystem, name string) (int, error) {
 	f, err := fs.Open(name)
 	if err != nil {
-		// TODO expose actual error?
+		if os.IsPermission(err) {
-		http.NotFound(w, r)
+			return http.StatusForbidden, err
-		return
+		}
+		return http.StatusNotFound, nil
 	}
 	defer f.Close()
 
 	d, err1 := f.Stat()
 	if err1 != nil {
-		// TODO expose actual error?
+		if os.IsPermission(err) {
-		http.NotFound(w, r)
+			return http.StatusForbidden, err
-		return
+		}
+		return http.StatusNotFound, nil
 	}
 
 	// use contents of an index file, if present, for directory
@@ -69,10 +73,14 @@ func serveFile(w http.ResponseWriter, r *http.Request, fs http.FileSystem, name
 	}
 
 	// Still a directory? (we didn't find an index file)
+	// Return 404 to hide the fact that the folder exists
 	if d.IsDir() {
-		http.NotFound(w, r) // 404 instead of 403 to hide the fact that the folder exists
+		return http.StatusNotFound, nil
-		return
 	}
 
+	// Note: Errors generated by ServeContent are written immediately
+	// to the response. This usually only happens if seeking fails (rare).
 	http.ServeContent(w, r, d.Name(), d.ModTime(), f)
+
+	return http.StatusOK, nil
 }