Workaround for negative vals in total*Used in nova absolute_limits

Due to bug 1370867 there is a case where negative values are returned
in total*Used in absolute_limits. If it occurs, Horizon Overview page
cannot be displayed due to an error "cannot convert float infinity to
integer". This commit replaces negative values in total*Used with 0
for a workarond.

Change-Id: I606803bdff1d335cc9f92d67619ff82f356a5143
Closes-Bug: #1370869

openstack_dashboard/api/nova.py

@@ -755,9 +755,15 @@ def tenant_absolute_limits(request, reserved=False):
     limits = novaclient(request).limits.get(reserved=reserved).absolute
     limits_dict = {}
     for limit in limits:
-        # -1 is used to represent unlimited quotas
-        if limit.value == -1:
-            limits_dict[limit.name] = float("inf")
+        if limit.value < 0:
+            # Workaround for nova bug 1370867 that absolute_limits
+            # returns negative value for total.*Used instead of 0.
+            # For such case, replace negative values with 0.
+            if limit.name.startswith('total') and limit.name.endswith('Used'):
+                limits_dict[limit.name] = 0
+            else:
+                # -1 is used to represent unlimited quotas
+                limits_dict[limit.name] = float("inf")
         else:
             limits_dict[limit.name] = limit.value
     return limits_dict

openstack_dashboard/test/api_tests/nova_tests.py

@@ -211,8 +211,7 @@ class ComputeApiTests(test.APITestCase):
         ret_val = api.nova.server_get(self.request, server.id)
         self.assertIsInstance(ret_val, api.nova.Server)
 
-    def test_absolute_limits_handle_unlimited(self):
-        values = {"maxTotalCores": -1, "maxTotalInstances": 10}
+    def _test_absolute_limits(self, values, expected_results):
         limits = self.mox.CreateMockAnything()
         limits.absolute = []
         for key, val in six.iteritems(values):
@@ -227,7 +226,30 @@ class ComputeApiTests(test.APITestCase):
         self.mox.ReplayAll()
 
         ret_val = api.nova.tenant_absolute_limits(self.request, reserved=True)
-        expected_results = {"maxTotalCores": float("inf"),
-                            "maxTotalInstances": 10}
         for key in expected_results.keys():
             self.assertEqual(expected_results[key], ret_val[key])
+
+    def test_absolute_limits_handle_unlimited(self):
+        values = {"maxTotalCores": -1, "maxTotalInstances": 10}
+        expected_results = {"maxTotalCores": float("inf"),
+                            "maxTotalInstances": 10}
+        self._test_absolute_limits(values, expected_results)
+
+    def test_absolute_limits_negative_used_workaround(self):
+        values = {"maxTotalCores": -1,
+                  "maxTotalInstances": 10,
+                  "totalInstancesUsed": -1,
+                  "totalCoresUsed": -1,
+                  "totalRAMUsed": -2048,
+                  "totalSecurityGroupsUsed": 1,
+                  "totalFloatingIpsUsed": 0,
+                  }
+        expected_results = {"maxTotalCores": float("inf"),
+                            "maxTotalInstances": 10,
+                            "totalInstancesUsed": 0,
+                            "totalCoresUsed": 0,
+                            "totalRAMUsed": 0,
+                            "totalSecurityGroupsUsed": 1,
+                            "totalFloatingIpsUsed": 0,
+                            }
+        self._test_absolute_limits(values, expected_results)