Modify wrong nodes message function, logging infos of monitor info

Using join method on the nodes list instead of string concatenation. Logging if monitor info unreachable or None in get_monitor_info method.

circle/dashboard/views/node.py

@@ -215,15 +215,14 @@ class NodeList(LoginRequiredMixin, GraphMixin, SingleTableView):
             number_of_VMs=Count('instance_set')).select_related('host')
 
     def wrong_nodes_message(self):
-        wrong_nodes = ''
+        wrong_nodes = []
         for node in Node.objects.all():
             if node.monitor_info is None:
-                if wrong_nodes != '':
-                    wrong_nodes += ','
-                wrong_nodes += ' ' + node.name
-        if wrong_nodes != '':
+                wrong_nodes.append(node.name)
+        message = ', '.join(wrong_nodes)
+        if wrong_nodes :
             messages.error(self.request,
-                           "Can't reach" + wrong_nodes + " monitor info")
+                           "Can't reach " + message + " monitor info")
 
 
 class NodeCreate(LoginRequiredMixin, SuperuserRequiredMixin, TemplateView):

circle/vm/models/node.py

@@ -367,8 +367,10 @@ class Node(OperatedMixin, TimeStampedModel):
         # return with the metric value if the monitor info not none
         # or return 0 if its None or the metric unreachable
         if self.monitor_info is None:
+            logger.warning('Monitor info is None')
             return 0
         elif self.monitor_info.get(metric) is None:
+            logger.warning('Unreachable monitor info of: ' + metric )
             return 0
         else:
             return self.monitor_info.get(metric)