dhcp: fix usage of helper function to retrieve process name

Usage of the helper function which retrieves the name of the process
based on the usage of the segments was missing for unregister which
leads an issue when disabling dhcp agent for a network.

Closes-Bug: #2051690
Signed-off-by: Sahid Orentino Ferdjaoui <[email protected]>
Change-Id: Ic6e999214210383f17c29982bf5673eea1bb55c0
(cherry picked from commit b37c0f4)
(cherry picked from commit 0b5ffd1)

Author: sahid

neutron/agent/linux/dhcp.py

@@ -357,8 +357,8 @@ def _get_process_manager(self, cmd_callback=None):
 
     def disable(self, retain_port=False, block=False, **kwargs):
         """Disable DHCP for this network by killing the local process."""
-        self.process_monitor.unregister(self.network.id, DNSMASQ_SERVICE_NAME)
         pm = self._get_process_manager()
+        self.process_monitor.unregister(pm.uuid, DNSMASQ_SERVICE_NAME)
         pm.disable(sig=str(int(signal.SIGTERM)))
         if block:
             try:
@@ -602,7 +602,7 @@ def _spawn_or_reload_process(self, reload_with_HUP):
 
         pm.enable(reload_cfg=reload_with_HUP, ensure_active=True)
 
-        self.process_monitor.register(uuid=self.get_process_uuid(),
+        self.process_monitor.register(uuid=pm.uuid,
                                       service_name=DNSMASQ_SERVICE_NAME,
                                       monitored_process=pm)
 

neutron/tests/unit/agent/linux/test_dhcp.py

@@ -1093,6 +1093,12 @@ def __init__(self):
         self.namespace = 'qdhcp-ns'
 
 
+class FakeSegment(object):
+    def __init__(self):
+        self.id = 'iiiiiiii-iiii-iiii-iiii-iiiiiiiiiiii'
+        self.segmentation_id = 1212
+
+
 class LocalChild(dhcp.DhcpLocalProcess):
     PORTS = {4: [4], 6: [6]}
 
@@ -1294,6 +1300,26 @@ def test_disable(self):
 
         delete_ns.assert_called_with('qdhcp-ns')
 
+    def test_disable_with_segment(self):
+        attrs_to_mock = {'active': mock.DEFAULT}
+
+        self.external_process().uuid = "1212/net-id"
+
+        with mock.patch.multiple(LocalChild, **attrs_to_mock) as mocks:
+            mocks['active'].__get__ = mock.Mock(return_value=False)
+            lp = LocalChild(
+                self.conf, FakeDualNetwork(), segment=FakeSegment())
+            with mock.patch('neutron.agent.linux.ip_lib.'
+                            'delete_network_namespace') as delete_ns:
+                lp.disable()
+                self.rmtree.assert_called_once()
+
+            lp.process_monitor.unregister.assert_called_once_with(
+                '1212/net-id', 'dnsmasq')
+            self.assertTrue(self.external_process().disable.called)
+
+        delete_ns.assert_called_with('qdhcp-ns')
+
     def test_enable_disable_two_networks(self):
         attrs_to_mock = {'active': mock.DEFAULT}