PostForm: Follow success_action_status requirement (#3467)

S3 spec requires that Post Object response depends on the passed success_action_status. This commit implements that requirement.

cmd/api-response.go

@@ -251,6 +251,14 @@ type DeleteObjectsResponse struct {
 	Errors []DeleteError `xml:"Error,omitempty"`
 }
 
+// PostResponse container for POST object request when success_action_status is set to 201
+type PostResponse struct {
+	Bucket   string
+	Key      string
+	ETag     string
+	Location string
+}
+
 // getLocation get URL location.
 func getLocation(r *http.Request) string {
 	return path.Clean(r.URL.Path) // Clean any trailing slashes.
@@ -474,21 +482,24 @@ func generateMultiDeleteResponse(quiet bool, deletedObjects []ObjectIdentifier,
 	return deleteResp
 }
 
-// writeSuccessResponse write success headers and response if any.
-func writeSuccessResponse(w http.ResponseWriter, response []byte) {
+func writeResponse(w http.ResponseWriter, statusCode int, response []byte) {
 	setCommonHeaders(w)
+	w.WriteHeader(statusCode)
 	if response == nil {
-		w.WriteHeader(http.StatusOK)
 		return
 	}
 	w.Write(response)
 	w.(http.Flusher).Flush()
 }
 
+// writeSuccessResponse write success headers and response if any.
+func writeSuccessResponse(w http.ResponseWriter, response []byte) {
+	writeResponse(w, http.StatusOK, response)
+}
+
 // writeSuccessNoContent write success headers with http status 204
 func writeSuccessNoContent(w http.ResponseWriter) {
-	setCommonHeaders(w)
-	w.WriteHeader(http.StatusNoContent)
+	writeResponse(w, http.StatusNoContent, nil)
 }
 
 // writeErrorRespone write error headers

cmd/bucket-handlers.go

@@ -448,11 +448,22 @@ func (api objectAPIHandlers) PostPolicyBucketHandler(w http.ResponseWriter, r *h
 	w.Header().Set("ETag", "\""+objInfo.MD5Sum+"\"")
 	w.Header().Set("Location", getObjectLocation(bucket, object))
 
-	// Set common headers.
-	setCommonHeaders(w)
+	// Decide what http response to send depending on success_action_status parameter
+	switch formValues[http.CanonicalHeaderKey("success_action_status")] {
+	case "201":
+		resp := encodeResponse(PostResponse{
+			Bucket:   bucket,
+			Key:      object,
+			ETag:     "\"" + objInfo.MD5Sum + "\"",
+			Location: getObjectLocation(bucket, object),
+		})
+		writeResponse(w, http.StatusCreated, resp)
 
-	// Write successful response.
+	case "200":
+		writeSuccessResponse(w, nil)
+	default:
 		writeSuccessNoContent(w)
+	}
 
 	// Notify object created event.
 	eventNotify(eventData{