diff --git a/tripleo_common/inventory.py b/tripleo_common/inventory.py
index ac4b22ee1..4520da04a 100644
--- a/tripleo_common/inventory.py
+++ b/tripleo_common/inventory.py
@@ -106,6 +106,7 @@ class TripleoInventory(object):
             self.ansible_ssh_user = ansible_ssh_user
             self.plan_name = plan_name
         self.stack_outputs = StackOutputs(self.plan_name, self.hclient)
+        self.hostvars = {}
 
     @staticmethod
     def get_roles_by_service(enabled_services):
@@ -152,10 +153,9 @@ class TripleoInventory(object):
     def list(self):
         ret = OrderedDict({
             'Undercloud': {
-                'hosts': {
-                    'undercloud': {
-                        'ansible_host': 'localhost'}},
+                'hosts': self._hosts(['undercloud']),
                 'vars': {
+                    'ansible_host': 'localhost',
                     'ansible_connection': 'local',
                     # see https://github.com/ansible/ansible/issues/41808
                     'ansible_remote_tmp': '/tmp/ansible-${USER}',
@@ -229,16 +229,26 @@ class TripleoInventory(object):
                     networks.update(hosts[name]['enabled_networks'])
 
                 children.append(role)
+
+                if self.hosts_format_dict:
+                    hosts_format = hosts
+                else:
+                    hosts_format = [h for h in hosts.keys()]
+                    hosts_format.sort()
+
                 ret[role] = {
-                    'hosts': hosts,
+                    'hosts': hosts_format,
                     'vars': {
                         'ansible_ssh_user': self.ansible_ssh_user,
                         'bootstrap_server_id': role_node_id_map.get(
                             'bootstrap_server_id'),
                         'role_name': role,
                     }
+
                 }
 
+                self.hostvars.update(hosts)
+
         if children:
             vip_map = self.stack_outputs.get('VipMap', {})
             vips = {(vip_name + "_vip"): vip
@@ -263,8 +273,10 @@ class TripleoInventory(object):
                     }
                 }
 
-        # Prevent Ansible from repeatedly calling us to get empty host details
-        ret['_meta'] = {'hostvars': {}}
+        if not self.hosts_format_dict:
+            # Prevent Ansible from repeatedly calling us to get empty host
+            # details
+            ret['_meta'] = {'hostvars': self.hostvars}
 
         return ret
 
diff --git a/tripleo_common/tests/test_inventory.py b/tripleo_common/tests/test_inventory.py
index 4a4b773de..1cd21b8a7 100644
--- a/tripleo_common/tests/test_inventory.py
+++ b/tripleo_common/tests/test_inventory.py
@@ -189,42 +189,17 @@ class TestInventory(base.TestCase):
         ansible_ssh_user = 'heat-admin'
         expected = {
             'Compute': {
-                'hosts': {
-                    'cp-0': {
-                        'ansible_host': 'y.y.y.1',
-                        'ctlplane_ip': 'y.y.y.1',
-                        'deploy_server_id': 'd',
-                        'enabled_networks': ['ctlplane']}},
+                'hosts': ['cp-0'],
                 'vars': {'ansible_ssh_user': ansible_ssh_user,
                          'bootstrap_server_id': 'a',
                          'role_name': 'Compute'}},
             'Controller': {
-                'hosts': {
-                    'c-0': {
-                        'ansible_host': 'x.x.x.1',
-                        'ctlplane_ip': 'x.x.x.1',
-                        'deploy_server_id': 'a',
-                        'enabled_networks': ['ctlplane']},
-                    'c-1': {
-                        'ansible_host': 'x.x.x.2',
-                        'ctlplane_ip': 'x.x.x.2',
-                        'deploy_server_id': 'b',
-                        'enabled_networks': ['ctlplane']},
-                    'c-2': {
-                        'ansible_host': 'x.x.x.3',
-                        'ctlplane_ip': 'x.x.x.3',
-                        'deploy_server_id': 'c',
-                        'enabled_networks': ['ctlplane']}},
+                'hosts': ['c-0', 'c-1', 'c-2'],
                 'vars': {'ansible_ssh_user': ansible_ssh_user,
                          'bootstrap_server_id': 'a',
                          'role_name': 'Controller'}},
             'CustomRole': {
-                'hosts': {
-                    'cs-0': {
-                        'ansible_host': 'z.z.z.1',
-                        'ctlplane_ip': 'z.z.z.1',
-                        'deploy_server_id': 'e',
-                        'enabled_networks': ['ctlplane']}},
+                'hosts': ['cs-0'],
                 'vars': {'ansible_ssh_user': ansible_ssh_user,
                          'bootstrap_server_id': 'a',
                          'role_name': 'CustomRole'}},
@@ -235,10 +210,9 @@ class TestInventory(base.TestCase):
                     'ctlplane_vip': 'x.x.x.4',
                     'redis_vip': 'x.x.x.6'}},
             'Undercloud': {
-                'hosts': {
-                    'undercloud': {
-                        'ansible_host': 'localhost'}},
+                'hosts': ['undercloud'],
                 'vars': {'ansible_connection': 'local',
+                         'ansible_host': 'localhost',
                          'ansible_remote_tmp': '/tmp/ansible-${USER}',
                          'auth_url': 'xyz://keystone.local',
                          'cacert': 'acacert',
@@ -285,42 +259,17 @@ class TestInventory(base.TestCase):
 
         expected = {
             'Compute': {
-                'hosts': {
-                    'cp-0': {
-                        'ansible_host': 'y.y.y.1',
-                        'ctlplane_ip': 'y.y.y.1',
-                        'deploy_server_id': 'd',
-                        'enabled_networks': ['ctlplane']}},
+                'hosts': ['cp-0'],
                 'vars': {'ansible_ssh_user': ansible_ssh_user,
                          'bootstrap_server_id': 'a',
                          'role_name': 'Compute'}},
             'Controller': {
-                'hosts': {
-                    'c-0': {
-                        'ansible_host': 'x.x.x.1',
-                        'ctlplane_ip': 'x.x.x.1',
-                        'deploy_server_id': 'a',
-                        'enabled_networks': ['ctlplane']},
-                    'c-1': {
-                        'ansible_host': 'x.x.x.2',
-                        'ctlplane_ip': 'x.x.x.2',
-                        'deploy_server_id': 'b',
-                        'enabled_networks': ['ctlplane']},
-                    'c-2': {
-                        'ansible_host': 'x.x.x.3',
-                        'ctlplane_ip': 'x.x.x.3',
-                        'deploy_server_id': 'c',
-                        'enabled_networks': ['ctlplane']}},
+                'hosts': ['c-0', 'c-1', 'c-2'],
                 'vars': {'ansible_ssh_user': ansible_ssh_user,
                          'bootstrap_server_id': 'a',
                          'role_name': 'Controller'}},
             'CustomRole': {
-                'hosts': {
-                    'cs-0': {
-                        'ansible_host': 'z.z.z.1',
-                        'ctlplane_ip': 'z.z.z.1',
-                        'deploy_server_id': 'e',
-                        'enabled_networks': ['ctlplane']}},
+                'hosts': ['cs-0'],
                 'vars': {'ansible_ssh_user': ansible_ssh_user,
                          'bootstrap_server_id': 'a',
                          'role_name': 'CustomRole'}},
@@ -330,10 +279,9 @@ class TestInventory(base.TestCase):
                     'ctlplane_vip': 'x.x.x.4',
                     'redis_vip': 'x.x.x.6'}},
             'Undercloud': {
-                'hosts': {
-                    'undercloud': {
-                        'ansible_host': 'localhost'}},
+                'hosts': ['undercloud'],
                 'vars': {'ansible_connection': 'local',
+                         'ansible_host': 'localhost',
                          'ansible_remote_tmp': '/tmp/ansible-${USER}',
                          'auth_url': 'xyz://keystone.local',
                          'cacert': 'acacert',
@@ -411,7 +359,6 @@ class TestInventory(base.TestCase):
                 'vars': {'ansible_ssh_user': ansible_ssh_user,
                          'bootstrap_server_id': 'a',
                          'role_name': 'CustomRole'}},
-            '_meta': {'hostvars': {}},
             'overcloud': {'children': {'Compute': {},
                                        'Controller': {},
                                        'CustomRole': {}},
@@ -429,9 +376,9 @@ class TestInventory(base.TestCase):
                    'vars': {'ansible_ssh_user': 'heat-admin'}},
             'sh': {'children': {'CustomRole': {}},
                    'vars': {'ansible_ssh_user': 'heat-admin'}},
-            'Undercloud': {'hosts': {'undercloud': {
-                                     'ansible_host': 'localhost'}},
+            'Undercloud': {'hosts': {'undercloud': {}},
                            'vars': {'ansible_connection': 'local',
+                                    'ansible_host': 'localhost',
                                     'ansible_remote_tmp':
                                         '/tmp/ansible-${USER}',
                                     'auth_url': 'xyz://keystone.local',