handler: Add callback to UnroutedHandler to remove restriction on upload URIs.

Fixes #340

pkg/handler/unrouted_handler.go

@@ -9,6 +9,7 @@ import (
 	"math"
 	"net"
 	"net/http"
+	uri "net/url"
 	"os"
 	"regexp"
 	"strconv"
@@ -112,12 +113,10 @@ func newHookEvent(info FileInfo, r *http.Request) HookEvent {
 // such as PostFile, HeadFile, PatchFile and DelFile. In addition the GetFile method
 // is provided which is, however, not part of the specification.
 type UnroutedHandler struct {
-	config        Config
+	config     Config
-	composer      *StoreComposer
+	composer   *StoreComposer
-	isBasePathAbs bool
+	logger     *log.Logger
-	basePath      string
+	extensions string
-	logger        *log.Logger
-	extensions    string
 
 	// CompleteUploads is used to send notifications whenever an upload is
 	// completed by a user. The HookEvent will contain information about this
@@ -149,6 +148,10 @@ type UnroutedHandler struct {
 	CreatedUploads chan HookEvent
 	// Metrics provides numbers of the usage for this handler.
 	Metrics Metrics
+	// GetID is a customisable callback used by the handler to determine the id of an upload in a request
+	GetID func(r *http.Request) (string, error)
+	// GetURL is a customisable callback used by the handler to determine the url that uniquely identifies the resource id
+	GetURL func(r *http.Request, id string) (*uri.URL, error)
 }
 
 // NewUnroutedHandler creates a new handler without routing using the given
@@ -175,8 +178,6 @@ func NewUnroutedHandler(config Config) (*UnroutedHandler, error) {
 	handler := &UnroutedHandler{
 		config:            config,
 		composer:          config.StoreComposer,
-		basePath:          config.BasePath,
-		isBasePathAbs:     config.isAbs,
 		CompleteUploads:   make(chan HookEvent),
 		TerminatedUploads: make(chan HookEvent),
 		UploadProgress:    make(chan HookEvent),
@@ -184,6 +185,21 @@ func NewUnroutedHandler(config Config) (*UnroutedHandler, error) {
 		logger:            config.Logger,
 		extensions:        extensions,
 		Metrics:           newMetrics(),
+		GetID: func(r *http.Request) (string, error) {
+			return extractIDFromPath(r.URL.Path)
+		},
+		GetURL: func(r *http.Request, id string) (*uri.URL, error) {
+			if config.isAbs {
+				return uri.Parse(config.BasePath + id)
+			}
+
+			// Read origin and protocol from request
+			host, proto := getHostAndProtocol(r, config.RespectForwardedHeaders)
+
+			url := proto + "://" + host + config.BasePath + id
+
+			return uri.Parse(url)
+		},
 	}
 
 	return handler, nil
@@ -289,12 +305,33 @@ func (handler *UnroutedHandler) PostFile(w http.ResponseWriter, r *http.Request)
 	}
 
 	// Parse Upload-Concat header
-	isPartial, isFinal, partialUploadIDs, err := parseConcat(concatHeader)
+	isPartial, isFinal, partialUploadPaths, err := parseConcat(concatHeader)
 	if err != nil {
 		handler.sendError(w, r, err)
 		return
 	}
 
+	var partialUploadIDs []string
+	if len(partialUploadPaths) > 0 {
+		partialUploadIDs = make([]string, len(partialUploadPaths))
+		origURL := r.URL
+		for i, path := range partialUploadPaths {
+			// insert partialUpload URI and call GetID
+			r.URL, err = r.URL.Parse(path)
+			if err != nil {
+				handler.sendError(w, r, err)
+				return
+			}
+
+			partialUploadIDs[i], err = handler.GetID(r)
+			if err != nil {
+				handler.sendError(w, r, err)
+				return
+			}
+		}
+		r.URL = origURL
+	}
+
 	// If the upload is a final upload created by concatenation multiple partial
 	// uploads the size is sum of all sizes of these files (no need for
 	// Upload-Length header)
@@ -364,11 +401,15 @@ func (handler *UnroutedHandler) PostFile(w http.ResponseWriter, r *http.Request)
 
 	// Add the Location header directly after creating the new resource to even
 	// include it in cases of failure when an error is returned
-	url := handler.absFileURL(r, id)
+	url, err := handler.GetURL(r, id)
-	w.Header().Set("Location", url)
+	if err != nil {
+		handler.sendError(w, r, err)
+		return
+	}
+	w.Header().Set("Location", url.String())
 
 	handler.Metrics.incUploadsCreated()
-	handler.log("UploadCreated", "id", id, "size", i64toa(size), "url", url)
+	handler.log("UploadCreated", "id", id, "size", i64toa(size), "url", url.String())
 
 	if handler.config.NotifyCreatedUploads {
 		handler.CreatedUploads <- newHookEvent(info, r)
@@ -416,7 +457,7 @@ func (handler *UnroutedHandler) PostFile(w http.ResponseWriter, r *http.Request)
 func (handler *UnroutedHandler) HeadFile(w http.ResponseWriter, r *http.Request) {
 	ctx := context.Background()
 
-	id, err := extractIDFromPath(r.URL.Path)
+	id, err := handler.GetID(r)
 	if err != nil {
 		handler.sendError(w, r, err)
 		return
@@ -452,7 +493,12 @@ func (handler *UnroutedHandler) HeadFile(w http.ResponseWriter, r *http.Request)
 	if info.IsFinal {
 		v := "final;"
 		for _, uploadID := range info.PartialUploads {
-			v += handler.absFileURL(r, uploadID) + " "
+			url, err := handler.GetURL(r, uploadID)
+			if err != nil {
+				handler.sendError(w, r, err)
+				return
+			}
+			v += url.String() + " "
 		}
 		// Remove trailing space
 		v = v[:len(v)-1]
@@ -493,7 +539,7 @@ func (handler *UnroutedHandler) PatchFile(w http.ResponseWriter, r *http.Request
 		return
 	}
 
-	id, err := extractIDFromPath(r.URL.Path)
+	id, err := handler.GetID(r)
 	if err != nil {
 		handler.sendError(w, r, err)
 		return
@@ -695,7 +741,7 @@ func (handler *UnroutedHandler) finishUploadIfComplete(ctx context.Context, uplo
 func (handler *UnroutedHandler) GetFile(w http.ResponseWriter, r *http.Request) {
 	ctx := context.Background()
 
-	id, err := extractIDFromPath(r.URL.Path)
+	id, err := handler.GetID(r)
 	if err != nil {
 		handler.sendError(w, r, err)
 		return
@@ -822,7 +868,7 @@ func (handler *UnroutedHandler) DelFile(w http.ResponseWriter, r *http.Request)
 		return
 	}
 
-	id, err := extractIDFromPath(r.URL.Path)
+	id, err := handler.GetID(r)
 	if err != nil {
 		handler.sendError(w, r, err)
 		return
@@ -934,21 +980,6 @@ func (handler *UnroutedHandler) sendResp(w http.ResponseWriter, r *http.Request,
 	handler.log("ResponseOutgoing", "status", strconv.Itoa(status), "method", r.Method, "path", r.URL.Path)
 }
 
-// Make an absolute URLs to the given upload id. If the base path is absolute
-// it will be prepended else the host and protocol from the request is used.
-func (handler *UnroutedHandler) absFileURL(r *http.Request, id string) string {
-	if handler.isBasePathAbs {
-		return handler.basePath + id
-	}
-
-	// Read origin and protocol from request
-	host, proto := getHostAndProtocol(r, handler.config.RespectForwardedHeaders)
-
-	url := proto + "://" + host + handler.basePath + id
-
-	return url
-}
-
 type progressWriter struct {
 	Offset int64
 }
@@ -1171,13 +1202,7 @@ func parseConcat(header string) (isPartial bool, isFinal bool, partialUploads []
 				continue
 			}
 
-			id, extractErr := extractIDFromPath(value)
+			partialUploads = append(partialUploads, value)
-			if extractErr != nil {
-				err = extractErr
-				return
-			}
-
-			partialUploads = append(partialUploads, id)
 		}
 	}