Protect against very large stdout fields

* Defer loading result_stdout_text until specifically needed
* Conditionally display it based on the size of the field
* Provide a helpful message otherwise

awx/api/views.py

@@ -2109,11 +2109,20 @@ class JobList(ListCreateAPIView):
     model = Job
     serializer_class = JobListSerializer
 
+    def get_queryset(self):
+        qs = self.request.user.get_queryset(self.model).defer('result_stdout_text')
+        return qs
+
 class JobDetail(RetrieveUpdateDestroyAPIView):
 
     model = Job
     serializer_class = JobSerializer
 
+    
+    def get_queryset(self):
+        qs = super(JobDetail, self).get_queryset().defer('result_stdout_text')
+        return qs
+
     def update(self, request, *args, **kwargs):
         obj = self.get_object()
         # Only allow changes (PUT/PATCH) when job status is "new".
@@ -2783,6 +2792,11 @@ class UnifiedJobList(ListAPIView):
     model = UnifiedJob
     serializer_class = UnifiedJobListSerializer
     new_in_148 = True
+    
+    def get_queryset(self):
+        qs = self.request.user.get_queryset(self.model).defer('result_stdout_text')
+        return qs
+
 
 class UnifiedJobStdout(RetrieveAPIView):
 
@@ -2793,8 +2807,17 @@ class UnifiedJobStdout(RetrieveAPIView):
     filter_backends = ()
     new_in_148 = True
 
+    def get_queryset(self):
+        qs = super(UnifiedJobStdout, self).get_queryset().defer('result_stdout_text')
+        return qs    
+
     def retrieve(self, request, *args, **kwargs):
         unified_job = self.get_object()
+        obj_size = unified_job.result_stdout_size
+        if request.accepted_renderer.format != 'txt_download' and obj_size > settings.STDOUT_MAX_BYTES_DISPLAY:
+            return Response("Standard Output too large to display (%d bytes), "
+                            "only download supported for sizes over %d bytes" % (obj_size, settings.STDOUT_MAX_BYTES_DISPLAY))
+
         if request.accepted_renderer.format in ('html', 'api', 'json'):
             start_line = request.QUERY_PARAMS.get('start_line', 0)
             end_line = request.QUERY_PARAMS.get('end_line', None)