Merge lp:~mpontillo/maas/external-dhcp--bug-1627363 into lp:~maas-committers/maas/trunk

[Mike Pontillo]

Log warning (instead of crashing) if a DHCP server is found on a disconnected interface.

[Gavin Panella (allenap)]

Looks good.

review: Approve

[Mike Pontillo (mpontillo)]

Thanks.

=== modified file 'src/maasserver/rpc/rackcontrollers.py'
--- src/maasserver/rpc/rackcontrollers.py	2016-09-14 01:50:41 +0000
+++ src/maasserver/rpc/rackcontrollers.py	2016-09-28 19:10:10 +0000
@@ -179,9 +179,16 @@
                 if rack_interfaces_serving_dhcp.exists():
                     # Not external. It's a MAAS DHCP server.
                     dhcp_ip = None
-        if interface.vlan.external_dhcp != dhcp_ip:
-            interface.vlan.external_dhcp = dhcp_ip
-            interface.vlan.save()
+        if interface.vlan is None:
+            maaslog.warning(
+                "%s: Detected an external DHCP server on an interface with no "
+                "VLAN defined: '%s': %s" % (
+                    rack_controller.hostname, interface.get_log_string(),
+                    dhcp_ip))
+        else:
+            if interface.vlan.external_dhcp != dhcp_ip:
+                interface.vlan.external_dhcp = dhcp_ip
+                interface.vlan.save()
 
 
 @synchronous
 
=== modified file 'src/maasserver/rpc/tests/test_rackcontrollers.py'
--- src/maasserver/rpc/tests/test_rackcontrollers.py	2016-08-18 14:47:07 +0000
+++ src/maasserver/rpc/tests/test_rackcontrollers.py	2016-09-28 19:10:10 +0000
@@ -38,7 +38,10 @@
 from maasserver.testing.factory import factory
 from maasserver.testing.testcase import MAASServerTestCase
 from maasserver.utils.orm import reload_object
-from maastesting.matchers import MockCalledOnceWith
+from maastesting.matchers import (
+    DocTestMatches,
+    MockCalledOnceWith,
+)
 from testtools.matchers import (
     IsInstance,
     MatchesAll,
@@ -328,6 +331,19 @@
         self.assertEquals(
             dhcp_ip, reload_object(interface.vlan).external_dhcp)
 
+    def test__logs_warning_for_external_dhcp_on_interface_no_vlan(self):
+        rack_controller = factory.make_RackController(interface=False)
+        interface = factory.make_Interface(
+            INTERFACE_TYPE.PHYSICAL, node=rack_controller)
+        dhcp_ip = factory.make_ip_address()
+        interface.vlan = None
+        interface.save()
+        logger = self.useFixture(FakeLogger())
+        update_foreign_dhcp(
+            rack_controller.system_id, interface.name, dhcp_ip)
+        self.assertThat(logger.output, DocTestMatches(
+            "...DHCP server on an interface with no VLAN defined..."))
+
     def test__clears_external_dhcp_when_managed_vlan(self):
         rack_controller = factory.make_RackController(interface=False)
         fabric = factory.make_Fabric()