Introduce group_names in template variables.

This is a list of all the groups a host is in.

test/TestInventory.py

@@ -85,13 +85,13 @@ class TestInventory(unittest.TestCase):
         inventory = self.simple_inventory()
         vars = inventory.get_variables('thor')
 
-        assert vars == {}
+        assert vars == {'group_names': ['norse']}
 
     def test_simple_port(self):
         inventory = self.simple_inventory()
         vars = inventory.get_variables('hera')
 
-        assert vars == {'ansible_ssh_port': 3000}
+        assert vars == {'ansible_ssh_port': 3000, 'group_names': ['greek']}
 
     ### Inventory API tests
 
@@ -146,7 +146,7 @@ class TestInventory(unittest.TestCase):
         inventory = self.script_inventory()
         vars = inventory.get_variables('thor')
 
-        assert vars == {"hammer":True}
+        assert vars == {"hammer":True, 'group_names': ['norse']}
 
     ### Tests for yaml inventory file
 
@@ -205,7 +205,7 @@ class TestInventory(unittest.TestCase):
         inventory = self.yaml_inventory()
         vars = inventory.get_variables('thor')
 
-        assert vars == {"hammer":True}
+        assert vars == {"hammer":True, 'group_names': ['norse']}
 
     def test_yaml_change_vars(self):
         inventory = self.yaml_inventory()
@@ -214,19 +214,30 @@ class TestInventory(unittest.TestCase):
         vars["hammer"] = False
 
         vars = inventory.get_variables('thor')
-        assert vars == {"hammer":True}
+        assert vars == {"hammer":True, 'group_names': ['norse']}
 
     def test_yaml_host_vars(self):
         inventory = self.yaml_inventory()
         vars = inventory.get_variables('saturn')
 
-        assert vars == {"moon":"titan", "moon2":"enceladus"}
+        assert vars == {"moon":"titan",
+                        "moon2":"enceladus",
+                        'group_names': ['multiple']}
 
     def test_yaml_port(self):
         inventory = self.yaml_inventory()
         vars = inventory.get_variables('hera')
 
-        assert vars == {'ansible_ssh_port': 3000, 'ntp_server': 'olympus.example.com'}
+        assert vars == {'ansible_ssh_port': 3000,
+                        'ntp_server': 'olympus.example.com',
+                        'group_names': ['greek']}
+
+    def test_yaml_multiple_groups(self):
+        inventory = self.yaml_inventory()
+        vars = inventory.get_variables('odin')
+
+        assert 'group_names' in vars
+        assert sorted(vars['group_names']) == [ 'norse', 'ruler' ]
 
     ### Test Runner class method
 

test/yaml_hosts

@@ -25,6 +25,11 @@
   - odin
   - loki
 
+- group: ruler
+  hosts:
+  - zeus
+  - odin
+
 - group: multiple
   hosts:
   - saturn