CI: Fix Multinode ssh key/hostname for unit tests

In multinode, the devstack plugin for networking-generic-switch can't
really work as intended. But, the authorized keys is copied on all
nodes, and zuul puts a consistent key in place, so it doesn't
really need to do what it is doing, but we need to use the stack
user's pre-existing keys to access the remote host.

This will allow Ironic's multinode grenade job to work without
errors about accessing the key file, which is a red herring for
when the connection fails.

Additionally, the underlying ngs code is suseptible to a race on
configuration loading as configuration is loaded separately.

We can't really force it to load the option. We also can't
explicitly add it, so the best thing to do is to wrap it and
rely upon a mock to facilitate the unit test.

Change-Id: Ia8550c124f2ef1cce620a4fb28c35700d34aa027
(cherry picked from commit c6c10a1)

Author: juliakreger

devstack/plugin.sh

@@ -145,6 +145,12 @@ function configure_generic_switch {
     if [ -n "$HOST_TOPOLOGY_SUBNODES" ]; then
         # NOTE(vsaienko) with multinode topology we need to add switches from all
         # the subnodes to the config on primary node
+        # NOTE(TheJulia) We *also* need to use the local key which will have
+        # access to the subnode instead of attemping to configure our own,
+        # as the plugins execute separately.
+        if [ -f /opt/stack/.ssh/id_rsa ]; then
+            GENERIC_SWITCH_KEY_FILE="/opt/stack/.ssh/id_rsa"
+        fi
         local cnt=0
         local section
         for node in $HOST_TOPOLOGY_SUBNODES; do

networking_generic_switch/devices/netmiko_devices/__init__.py

@@ -109,7 +109,7 @@ def __init__(self, device_cfg):
         if CONF.ngs_coordination.backend_url:
             self.locker = coordination.get_coordinator(
                 CONF.ngs_coordination.backend_url,
-                ('ngs-' + CONF.host).encode('ascii'))
+                ('ngs-' + device_utils.get_hostname()).encode('ascii'))
             self.locker.start()
             atexit.register(self.locker.stop)
 

networking_generic_switch/devices/utils.py

@@ -12,6 +12,11 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from oslo_config import cfg
+
+
+CONF = cfg.CONF
+
 
 def get_switch_device(switches, switch_info=None,
                       ngs_mac_address=None):
@@ -46,3 +51,8 @@ def sanitise_config(config):
         key: "******" if key in sanitised_fields else value
         for key, value in config.items()
     }
+
+
+def get_hostname():
+    """Helper to allow isolation of CONF.host and plugin loading."""
+    return CONF.host

networking_generic_switch/tests/unit/netmiko/test_netmiko_base.py

@@ -24,6 +24,7 @@
 from tooz import coordination
 
 from networking_generic_switch.devices import netmiko_devices
+from networking_generic_switch.devices import utils
 from networking_generic_switch import exceptions as exc
 
 
@@ -320,17 +321,18 @@ def fake_save_config():
         connect_mock.send_command.assert_has_calls([mock.call('save'),
                                                     mock.call('y')])
 
+    @mock.patch.object(utils, 'get_hostname', autospec=True)
     @mock.patch.object(netmiko_devices.ngs_lock, 'PoolLock', autospec=True)
     @mock.patch.object(netmiko_devices.netmiko, 'ConnectHandler')
     @mock.patch.object(coordination, 'get_coordinator', autospec=True)
     def test_switch_send_commands_with_coordinator(self, get_coord_mock,
-                                                   nm_mock, lock_mock):
+                                                   nm_mock, lock_mock,
+                                                   mock_hostname):
         self.cfg.config(acquire_timeout=120, backend_url='mysql://localhost',
                         group='ngs_coordination')
-        self.cfg.config(host='viking')
         coord = mock.Mock()
         get_coord_mock.return_value = coord
-
+        mock_hostname.return_value = 'viking'
         switch = self._make_switch_device(
             extra_cfg={'ngs_max_connections': 2})
         self.assertEqual(coord, switch.locker)
@@ -348,6 +350,7 @@ def test_switch_send_commands_with_coordinator(self, get_coord_mock,
                                           timeout=120)
         lock_mock.return_value.__exit__.assert_called_once()
         lock_mock.return_value.__enter__.assert_called_once()
+        mock_hostname.assert_called_once()
 
     def test_check_output(self):
         self.switch.check_output('fake output', 'fake op')