Add helper to get uuids of machines w/OVN chassis

Refactor get_machines_for_application as generator function instead
of building and passing on static List.

unit_tests/utilities/test_zaza_utilities_juju.py

@@ -101,8 +101,8 @@ class TestJujuUtils(ut_utils.BaseTestCase):
 
         # Machine data
         self.assertEqual(
-            juju_utils.get_machines_for_application(self.application),
-            [self.machine])
+            next(juju_utils.get_machines_for_application(self.application)),
+            self.machine)
         self.get_application_status.assert_called_once()
 
         # Subordinate application has no units
@@ -115,9 +115,9 @@ class TestJujuUtils(ut_utils.BaseTestCase):
         self.get_application_status.side_effect = _get_application_status
 
         self.assertEqual(
-            juju_utils.get_machines_for_application(
-                self.subordinate_application),
-            [self.machine])
+            next(juju_utils.get_machines_for_application(
+                self.subordinate_application)),
+            self.machine)
 
     def test_get_unit_name_from_host_name(self):
         unit_mock1 = mock.MagicMock()
@@ -151,8 +151,9 @@ class TestJujuUtils(ut_utils.BaseTestCase):
         self.get_machines_for_application.return_value = [self.machine]
 
         self.assertEqual(
-            juju_utils.get_machine_uuids_for_application(self.application),
-            [self.machine_data.get("instance-id")])
+            next(juju_utils.get_machine_uuids_for_application(
+                self.application)),
+            self.machine_data.get("instance-id"))
         self.get_machines_for_application.assert_called_once_with(
             self.application)
 

unit_tests/utilities/test_zaza_utilities_openstack.py

@@ -15,6 +15,7 @@
 import copy
 import datetime
 import io
+import itertools
 import mock
 import tenacity
 
@@ -814,12 +815,13 @@ class TestOpenStackUtils(ut_utils.BaseTestCase):
         )
 
         # No machine returned
-        self._get_machines.return_value = []
+        self._get_machines.side_effect = StopIteration
         with self.assertRaises(exceptions.ApplicationNotFound):
             openstack_utils.get_current_os_release_pair()
+        self._get_machines.side_effect = None
 
         # No series returned
-        self._get_machines.return_value = ['6']
+        self._get_machines.return_value = itertools.repeat('6')
         self._get_machine_series.return_value = None
         with self.assertRaises(exceptions.SeriesNotFound):
             openstack_utils.get_current_os_release_pair()
@@ -1165,3 +1167,30 @@ class TestOpenStackUtils(ut_utils.BaseTestCase):
                 'OS_PROJECT_NAME': 'services'},
             scope='PROJECT',
             verify=None)
+
+    def test_get_gateway_uuids(self):
+        self.patch_object(openstack_utils.juju_utils,
+                          'get_machine_uuids_for_application')
+        self.get_machine_uuids_for_application.return_value = 'ret'
+        self.assertEquals(openstack_utils.get_gateway_uuids(), 'ret')
+        self.get_machine_uuids_for_application.assert_called_once_with(
+            'neutron-gateway')
+
+    def test_get_ovs_uuids(self):
+        self.patch_object(openstack_utils.juju_utils,
+                          'get_machine_uuids_for_application')
+        self.get_machine_uuids_for_application.return_value = 'ret'
+        self.assertEquals(openstack_utils.get_ovs_uuids(), 'ret')
+        self.get_machine_uuids_for_application.assert_called_once_with(
+            'neutron-openvswitch')
+
+    def test_get_ovn_uuids(self):
+        self.patch_object(openstack_utils.juju_utils,
+                          'get_machine_uuids_for_application')
+        self.get_machine_uuids_for_application.return_value = ['ret']
+        self.assertEquals(list(openstack_utils.get_ovn_uuids()),
+                          ['ret', 'ret'])
+        self.get_machine_uuids_for_application.assert_has_calls([
+            mock.call('ovn-chassis'),
+            mock.call('ovn-dedicated-chassis'),
+        ])

zaza/openstack/utilities/juju.py

@@ -81,21 +81,18 @@ def get_machines_for_application(application):
 
     :param application: Application name
     :type application: string
-    :returns: List of machines for an application
-    :rtype: list
+    :returns: machines for an application
+    :rtype: Iterator[str]
     """
     status = get_application_status(application)
 
     # libjuju juju status no longer has units for subordinate charms
     # Use the application it is subordinate-to to find machines
     if status.get("units") is None and status.get("subordinate-to"):
-        return get_machines_for_application(status.get("subordinate-to")[0])
+        status = get_application_status(status.get("subordinate-to")[0])
 
-    machines = []
     for unit in status.get("units").keys():
-        machines.append(
-            status.get("units").get(unit).get("machine"))
-    return machines
+        yield status.get("units").get(unit).get("machine")
 
 
 def get_unit_name_from_host_name(host_name, application):
@@ -151,13 +148,11 @@ def get_machine_uuids_for_application(application):
 
     :param application: Application name
     :type application: string
-    :returns: List of machine uuuids for an application
-    :rtype: list
+    :returns: machine uuuids for an application
+    :rtype: Iterator[str]
     """
-    uuids = []
     for machine in get_machines_for_application(application):
-        uuids.append(get_machine_status(machine, key="instance-id"))
-    return uuids
+        yield get_machine_status(machine, key="instance-id")
 
 
 def get_provider_type():

zaza/openstack/utilities/openstack.py

@@ -45,6 +45,7 @@ from swiftclient import client as swiftclient
 
 import datetime
 import io
+import itertools
 import juju_wait
 import logging
 import os
@@ -55,8 +56,8 @@ import subprocess
 import sys
 import tempfile
 import tenacity
-import urllib
 import textwrap
+import urllib
 
 from zaza import model
 from zaza.openstack.utilities import (
@@ -434,7 +435,7 @@ def get_gateway_uuids():
     """Return machine uuids for neutron-gateway(s).
 
     :returns: List of uuids
-    :rtype: list
+    :rtype: Iterator[str]
     """
     return juju_utils.get_machine_uuids_for_application('neutron-gateway')
 
@@ -443,12 +444,24 @@ def get_ovs_uuids():
     """Return machine uuids for neutron-openvswitch(s).
 
     :returns: List of uuids
-    :rtype: list
+    :rtype: Iterator[str]
     """
     return (juju_utils
             .get_machine_uuids_for_application('neutron-openvswitch'))
 
 
+def get_ovn_uuids():
+    """Provide machine uuids for OVN Chassis.
+
+    :returns: List of uuids
+    :rtype: Iterator[str]
+    """
+    return itertools.chain(
+        juju_utils.get_machine_uuids_for_application('ovn-chassis'),
+        juju_utils.get_machine_uuids_for_application('ovn-dedicated-chassis'),
+    )
+
+
 BRIDGE_MAPPINGS = 'bridge-mappings'
 NEW_STYLE_NETWORKING = 'physnet1:br-ex'
 
@@ -1358,10 +1371,9 @@ def get_current_os_release_pair(application='keystone'):
     :raises: exceptions.SeriesNotFound
     :raises: exceptions.OSVersionNotFound
     """
-    machines = juju_utils.get_machines_for_application(application)
-    if len(machines) >= 1:
-        machine = machines[0]
-    else:
+    try:
+        machine = next(juju_utils.get_machines_for_application(application))
+    except StopIteration:
         raise exceptions.ApplicationNotFound(application)
 
     series = juju_utils.get_machine_series(machine)