api_views: test if file exists before returning the StreamingHttpResponse

petale/api_views.py

@@ -167,6 +167,7 @@ class PetalAPIView(APIView):
 
     @logit
     def get(self, request, partner_name, cut_uuid, petal_name):
+        logger = logging.getLogger(__name__)
         if_none_match = request.META.get('HTTP_IF_NONE_MATCH')
         if_none_match = if_none_match and map(str.strip, if_none_match.split(','))
 
@@ -179,6 +180,13 @@ class PetalAPIView(APIView):
                         'ETag': petal.etag
                     }
                 )
+        # verify file exists before creating a StreamingHttpResponse
+        # as StreamingHttpResponse generate its content after the Django global try/catch
+        try:
+            petal.data.open()
+        except IOError as e:
+            logger.error('file not found "%s": %s', petal.data.path, e)
+            return HttpResponse('missing file', status=500)
         response = StreamingHttpResponse(
             petal.data.chunks(),
             content_type=petal.content_type,

tests/test_api.py

@@ -1,3 +1,4 @@
+import os
 import json
 from xml.etree import ElementTree as etree
 
@@ -390,3 +391,16 @@ def test_cut_uuid_idp_checking(mocked_post, settings, app, acl):
                         headers=headers, status=201)
     assert CUT.objects.get(uuid=cut_uuid)
     assert Petal.objects.get(name='profile', cut__uuid=cut_uuid, partner__name='southpark')
+
+
+def test_storage_error(app, partner_southpark, cut_kevin_uuid, acl, caplog):
+    app.authorization = ('Basic', ('library', 'library'))
+
+    payload = json.loads(get_tests_file_content('books.json'))
+    url = '/api/southpark/%s/loans/' % cut_kevin_uuid
+
+    app.put_json(url, params=payload, headers={'If-None-Match': '*'}, status=201)
+
+    os.unlink(Petal.objects.get().data.path)
+
+    app.get(url, status=500)