Don't run metadata proxy when it is not needed

Bug #1159015

Change-Id: I6063e75525a2a727d063bb1745c897ac8c4ba3e8

quantum/agent/dhcp_agent.py

@@ -64,8 +64,8 @@ class DhcpAgent(manager.Manager):
                     help=_("Support Metadata requests on isolated networks.")),
         cfg.BoolOpt('enable_metadata_network', default=False,
                     help=_("Allows for serving metadata requests from a "
-                           "dedicate network. Requires "
+                           "dedicated network. Requires "
-                           "enable isolated_metadata = True ")),
+                           "enable_isolated_metadata = True")),
     ]
 
     def __init__(self, host=None):
@@ -184,7 +184,8 @@ class DhcpAgent(manager.Manager):
         for subnet in network.subnets:
             if subnet.enable_dhcp:
                 if self.call_driver('enable', network):
-                    if self.conf.use_namespaces:
+                    if (self.conf.use_namespaces and
+                        self.conf.enable_isolated_metadata):
                         self.enable_isolated_metadata_proxy(network)
                     self.cache.put(network)
                 break
@@ -193,7 +194,8 @@ class DhcpAgent(manager.Manager):
         """Disable DHCP for a network known to the agent."""
         network = self.cache.get_network_by_id(network_id)
         if network:
-            if self.conf.use_namespaces:
+            if (self.conf.use_namespaces and
+                self.conf.enable_isolated_metadata):
                 self.disable_isolated_metadata_proxy(network)
             if self.call_driver('disable', network):
                 self.cache.remove(network)

quantum/tests/unit/test_dhcp_agent.py

@@ -439,13 +439,16 @@ class TestDhcpAgentEventHandler(base.BaseTestCase):
         cfg.CONF.reset()
         super(TestDhcpAgentEventHandler, self).tearDown()
 
-    def test_enable_dhcp_helper(self):
+    def _enable_dhcp_helper(self, isolated_metadata=False):
+        if isolated_metadata:
+            cfg.CONF.set_override('enable_isolated_metadata', True)
         self.plugin.get_network_info.return_value = fake_network
         self.dhcp.enable_dhcp_helper(fake_network.id)
         self.plugin.assert_has_calls(
             [mock.call.get_network_info(fake_network.id)])
         self.call_driver.assert_called_once_with('enable', fake_network)
         self.cache.assert_has_calls([mock.call.put(fake_network)])
+        if isolated_metadata:
             self.external_process.assert_has_calls([
                 mock.call(
                     cfg.CONF,
@@ -454,6 +457,14 @@ class TestDhcpAgentEventHandler(base.BaseTestCase):
                     'qdhcp-12345678-1234-5678-1234567890ab'),
                 mock.call().enable(mock.ANY)
             ])
+        else:
+            self.assertFalse(self.external_process.call_count)
+
+    def test_enable_dhcp_helper_enable_isolated_metadata(self):
+        self._enable_dhcp_helper(isolated_metadata=True)
+
+    def test_enable_dhcp_helper(self):
+        self._enable_dhcp_helper()
 
     def test_enable_dhcp_helper_down_network(self):
         self.plugin.get_network_info.return_value = fake_down_network
@@ -486,12 +497,15 @@ class TestDhcpAgentEventHandler(base.BaseTestCase):
         self.assertFalse(self.cache.called)
         self.assertFalse(self.external_process.called)
 
-    def test_disable_dhcp_helper_known_network(self):
+    def _disable_dhcp_helper_known_network(self, isolated_metadata=False):
+        if isolated_metadata:
+            cfg.CONF.set_override('enable_isolated_metadata', True)
         self.cache.get_network_by_id.return_value = fake_network
         self.dhcp.disable_dhcp_helper(fake_network.id)
         self.cache.assert_has_calls(
             [mock.call.get_network_by_id(fake_network.id)])
         self.call_driver.assert_called_once_with('disable', fake_network)
+        if isolated_metadata:
             self.external_process.assert_has_calls([
                 mock.call(
                     cfg.CONF,
@@ -500,16 +514,26 @@ class TestDhcpAgentEventHandler(base.BaseTestCase):
                     'qdhcp-12345678-1234-5678-1234567890ab'),
                 mock.call().disable()
             ])
+        else:
+            self.assertFalse(self.external_process.call_count)
+
+    def test_disable_dhcp_helper_known_network_isolated_metadata(self):
+        self._disable_dhcp_helper_known_network(isolated_metadata=True)
+
+    def test_disable_dhcp_helper_known_network(self):
+        self._disable_dhcp_helper_known_network()
 
     def test_disable_dhcp_helper_unknown_network(self):
         self.cache.get_network_by_id.return_value = None
         self.dhcp.disable_dhcp_helper('abcdef')
         self.cache.assert_has_calls(
             [mock.call.get_network_by_id('abcdef')])
-        self.assertEqual(self.call_driver.call_count, 0)
+        self.assertEqual(0, self.call_driver.call_count)
         self.assertFalse(self.external_process.called)
 
-    def test_disable_dhcp_helper_driver_failure(self):
+    def _disable_dhcp_helper_driver_failure(self, isolated_metadata=False):
+        if isolated_metadata:
+            cfg.CONF.set_override('enable_isolated_metadata', True)
         self.cache.get_network_by_id.return_value = fake_network
         self.call_driver.return_value = False
         self.dhcp.disable_dhcp_helper(fake_network.id)
@@ -518,6 +542,7 @@ class TestDhcpAgentEventHandler(base.BaseTestCase):
         self.call_driver.assert_called_once_with('disable', fake_network)
         self.cache.assert_has_calls(
             [mock.call.get_network_by_id(fake_network.id)])
+        if isolated_metadata:
             self.external_process.assert_has_calls([
                 mock.call(
                     cfg.CONF,
@@ -526,6 +551,14 @@ class TestDhcpAgentEventHandler(base.BaseTestCase):
                     'qdhcp-12345678-1234-5678-1234567890ab'),
                 mock.call().disable()
             ])
+        else:
+            self.assertFalse(self.external_process.call_count)
+
+    def test_disable_dhcp_helper_driver_failure_isolated_metadata(self):
+        self._disable_dhcp_helper_driver_failure(isolated_metadata=True)
+
+    def test_disable_dhcp_helper_driver_failure(self):
+        self._disable_dhcp_helper_driver_failure()
 
     def test_enable_isolated_metadata_proxy(self):
         class_path = 'quantum.agent.linux.external_process.ProcessManager'