Ensure that haproxy spawned by the metadata agents is active

In both neutron-metadata and neutron-ovn-metadata agents we should
ensure that haproxy service spawned for network/router is actually
active before moving on.
This patch adds that check and this is similar to what was already
implemented some time ago for the dnsmasq process spawned by the dhcp
agent.

Related-Bug: #2052787
Change-Id: Ic58640d89952fa03bd1059608ee6c9072fbaabf5
(cherry picked from commit 2f7f7c2)

Author: slawqo

neutron/agent/metadata/driver.py

@@ -270,7 +270,7 @@ def spawn_monitored_metadata_proxy(cls, monitor, ns_name, port, conf,
                                                      ns_name=ns_name,
                                                      callback=callback)
         try:
-            pm.enable()
+            pm.enable(ensure_active=True)
         except exceptions.ProcessExecutionError as exec_err:
             LOG.error("Encountered process execution error %(err)s while "
                       "starting process in namespace %(ns)s",

neutron/agent/ovn/metadata/driver.py

@@ -181,7 +181,7 @@ def spawn_monitored_metadata_proxy(cls, monitor, ns_name, port, conf,
                                                      ns_name=ns_name,
                                                      callback=callback)
         try:
-            pm.enable()
+            pm.enable(ensure_active=True)
         except exceptions.ProcessExecutionError as exec_err:
             LOG.error("Encountered process execution error %(err)s while "
                       "starting process in namespace %(ns)s",

neutron/tests/unit/agent/dhcp/test_agent.py

@@ -658,6 +658,7 @@ def test_dhcp_ready_ports_updates_after_enable_dhcp(self, *args):
                         'IpAddrCommand.wait_until_address_ready') as mock_wait:
             mock_wait.return_value = True
             dhcp = dhcp_agent.DhcpAgent(HOSTNAME)
+            dhcp.update_isolated_metadata_proxy = mock.Mock()
             self.assertEqual(set(), dhcp.dhcp_ready_ports)
             dhcp.configure_dhcp_for_network(fake_network)
             self.assertEqual({fake_port1.id}, dhcp.dhcp_ready_ports)
@@ -854,7 +855,7 @@ def _enable_dhcp_helper(self, network, enable_isolated_metadata=False,
                 is_ovn_network):
             process_instance.assert_has_calls([
                 mock.call.disable(sig=str(int(signal.SIGTERM))),
-                mock.call.enable()])
+                mock.call.enable(ensure_active=True)])
         else:
             process_instance.assert_has_calls([
                 mock.call.disable(sig=str(int(signal.SIGTERM)))])

neutron/tests/unit/agent/metadata/test_driver.py

@@ -171,7 +171,12 @@ def _test_spawn_metadata_proxy(self, dad_failed=False):
                     'IpAddrCommand.wait_until_address_ready') as mock_wait,\
                 mock.patch(
                     'neutron.agent.linux.ip_lib.'
-                    'delete_ip_address') as mock_del:
+                    'delete_ip_address') as mock_del,\
+                mock.patch(
+                    'neutron.agent.linux.external_process.'
+                    'ProcessManager.active',
+                    new_callable=mock.PropertyMock,
+                    side_effect=[False, True]):
             agent = l3_agent.L3NATAgent('localhost')
             agent.process_monitor = mock.Mock()
             cfg_file = os.path.join(

neutron/tests/unit/agent/ovn/metadata/test_driver.py

@@ -74,7 +74,12 @@ def test_spawn_metadata_proxy(self):
                            return_value=test_utils.FakeUser(self.EUNAME)),\
                 mock.patch('grp.getgrnam',
                            return_value=test_utils.FakeGroup(self.EGNAME)),\
-                mock.patch('os.makedirs'):
+                mock.patch('os.makedirs'),\
+                mock.patch(
+                    'neutron.agent.linux.external_process.'
+                    'ProcessManager.active',
+                    new_callable=mock.PropertyMock,
+                    side_effect=[False, True]):
             cfg_file = os.path.join(
                 metadata_driver.HaproxyConfigurator.get_config_path(
                     cfg.CONF.state_path),