Handle nginx 499s and double requests

cms/djangoapps/contentstore/views/import_export.py

@@ -89,16 +89,20 @@ def import_course(request, org, course, name):
             # Check to make sure we haven't missed a chunk
             # This shouldn't happen, even if different instances are handling
             # the same session, but it's always better to catch errors earlier.
-            if size != int(content_range['start']):
+            if size < int(content_range['start']):
                 log.warning(
                     "Reported range %s does not match size downloaded so far %s",
-                    size,
-                    content_range['start']
+                    content_range['start'],
+                    size
                 )
                 return JsonResponse(
                     {'ErrMsg': 'File upload corrupted. Please try again'},
                     status=409
                 )
+            # The last request sometimes comes twice. This happens because
+            # nginx sends a 499 error code when the response takes too long.
+            elif size > int(content_range['stop']) and size == int(content_range['end']):
+                return JsonResponse({'ImportStatus': 1})
 
         with open(temp_filepath, mode) as temp_file:
             for chunk in request.FILES['course-data'].chunks():

cms/static/sass/views/_import.scss

@@ -57,6 +57,11 @@ body.course.import {
       color: $error-red;
     }
 
+    .status-block {
+      display: none;
+      font-size: 13px;
+    }
+
     .choose-file-button {
       @include blue-button;
       padding: 10px 50px 11px;

cms/templates/import.html

@@ -34,6 +34,7 @@
         <input type="file" name="course-data" class="file-input" >
         <input type="submit" value="${_('Replace my course with the one above')}" class="submit-button" >
         <input type="hidden" name="csrfmiddlewaretoken" value="${csrf_token}">
+        <p class="status-block">Unpacking...</p>
         <div class="progress-bar">
           <div class="progress-fill"></div>
           <div class="percent">0%</div>
@@ -55,6 +56,7 @@ var bar = $('.progress-bar');
 var fill = $('.progress-fill');
 var percent = $('.percent');
 var status = $('#status');
+var statusBlock = $('.status-block');
 var submitBtn = $('.submit-button');
 
 
@@ -79,6 +81,11 @@ $('#fileupload').fileupload({
                         alert('${_("Your import has failed.")}\n\n' + JSON.parse(result.responseText)["ErrMsg"]);
                         submitBtn.show();
                         bar.hide();
+                    } else {
+                        if (result.responseText["ImportStatus"] == 1) {
+                            bar.hide();
+                            statusBlock.show();
+                        }
                     }
                 });
             });