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.

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

Related-Bug: #2052787
Change-Id: Ic58640d89952fa03bd1059608ee6c9072fbaabf5
(cherry picked from commit 2f7f7c2fc2)
(cherry picked from commit 0dfe8dedd6)

neutron/agent/metadata/driver.py

@@ -295,7 +295,7 @@ class MetadataDriver(object):
                                                      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

@@ -206,7 +206,7 @@ class MetadataDriver(object):
                                                      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

@@ -637,6 +637,7 @@ class TestDhcpAgent(base.BaseTestCase):
                         '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)
@@ -834,7 +835,7 @@ class TestDhcpAgentEventHandler(base.BaseTestCase):
             process_instance.assert_has_calls([
                 mock.call.disable(sig=str(int(signal.SIGTERM))),
                 mock.call.get_pid_file_name(),
-                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

@@ -168,7 +168,12 @@ class TestMetadataDriverProcess(base.BaseTestCase):
                     '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

@@ -68,7 +68,12 @@ class TestMetadataDriverProcess(base.BaseTestCase):
                            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),