Added support for resource price changes.

When calculating the costs for a given resource, all the rows in the price table for that resource are going to be taken into consideration. The most recent price is going to be displayed in the costs page.

admin-costs-plugin/garr_costs/content/costs/utils.py

@@ -54,6 +54,10 @@ def get_volume_usage(request, resource, price_list, usage_start, usage_end, gnoc
     cost = '{0:.2f}'.format(0)
     usage = '{0:.2f}'.format(0)
 
+    if len(price_list)==1:
+        cost, usage = compute_volume_cost(resource, price_list[0][1], usage_start, usage_end, gnocchi_client)
+        return cost, usage, unit
+
     for i in range(len(price_list)-1):
         if price_list[i+1][0] < usage_start:
             #price[i+1] is older than usage_start
@@ -120,7 +124,7 @@ def get_volume_usage(request, resource, price_list, usage_start, usage_end, gnoc
 
     return cost, usage, unit
 
-def compute_instace_cost(resource, price, start_date, end_date, gnocchi_client):
+def compute_instance_cost(resource, price, start_date, end_date, gnocchi_client):
     cpu_util_measures = gnocchi_client.metric.get_measures(metric=resource['metrics']['cpu_util'],start=start_date,stop=end_date)
     hours_interval = (len(cpu_util_measures)*5)/60
         
@@ -135,6 +139,10 @@ def get_instance_usage(resource, price_list, usage_start, usage_end, gnocchi_cli
     usage = 0
     cost = '{0:.2f}'.format(0)
 
+    if len(price_list)==1:
+        cost, usage = compute_instance_cost(resource, price_list[0][1], usage_start, usage_end, gnocchi_client)
+        return cost, usage, unit
+
     for i in range(len(price_list)-1):
         if price_list[i+1][0] < usage_start:
             #price[i+1] is older than usage_start