Fix density processing

Change-Id: Idf1437fd5661d4455eb057a4a0c5631b2b517f04

scenarios/networking/l2_dense.yaml

@@ -5,7 +5,7 @@ description:
 
 deployment:
   template: l2.hot
-  vm_accommodation: [pair, double_room, density: 8, compute_nodes: 2]
+  vm_accommodation: [pair, single_room, density: 4, compute_nodes: 2]
 
 execution:
   size: 'quadratic_progression'

shaker/engine/deploy.py

@@ -30,7 +30,8 @@ def generate_agents(compute_nodes, vm_accommodation, unique):
     density = 1
     for s in vm_accommodation:
         if isinstance(s, dict):
-            density = s.get('density', 1)
+            if s.get('density'):
+                density = s.get('density')
             if s.get('compute_nodes'):
                 compute_nodes = compute_nodes[:s.get('compute_nodes')]
 

tests/test_deploy.py

@@ -176,6 +176,14 @@ class TestDeploy(testtools.TestCase):
                                         unique)
         self.assertEqual(expected, actual)
 
+    def test_generate_agents_pair_single_room_density_compute_nodes(self):
+        unique = 'UU1D'
+        actual = deploy.generate_agents(['uno', 'duo', 'tre'],
+                                        ['pair', 'single_room',
+                                         {'density': 4}, {'compute_nodes': 2}],
+                                        unique)
+        self.assertEqual(8, len(actual))
+
     def test_filter_agents_all_deployed(self):
         agents = {
             'UU1D_agent_0': {