Merge ~adam-collard/maas:update_vlan-log-string into maas:master

[Adam Collard]

Fix log message with Interface save

[MAAS Lander (maas-lander)]

UNIT TESTS
-b update_vlan-log-string lp:~adam-collard/maas/+git/maas into -b master lp:~maas-committers/maas

STATUS: SUCCESS
COMMIT: 3937cbb412b78152fa94e25c882a9022b66e0aa6

review: Approve

[Alberto Donato (ack)]

+1

review: Approve

[MAAS Lander (maas-lander)]

UNIT TESTS
-b update_vlan-log-string lp:~adam-collard/maas/+git/maas into -b master lp:~maas-committers/maas

STATUS: SUCCESS
COMMIT: 4a609d48ca55b8a51922ab44d1af2868a71b437e

review: Approve

diff --git a/src/maasserver/models/interface.py b/src/maasserver/models/interface.py
index 46b6e66..225bf7c 100644
--- a/src/maasserver/models/interface.py
+++ b/src/maasserver/models/interface.py
@@ -1661,7 +1661,7 @@ class Interface(CleanSave, TimestampedModel):
                     parent.vlan_id = self.vlan_id
                     parent.save()
                     maaslog.info(
-                        f"{parent.get_log_string}: "
+                        f"{parent.get_log_string()}: "
                         f"VLAN updated to match {self.get_log_string()} "
                         f"(vlan={parent.vlan_id})."
                     )
diff --git a/src/maasserver/models/tests/test_interface.py b/src/maasserver/models/tests/test_interface.py
index 4eba238..b9c2e9b 100644
--- a/src/maasserver/models/tests/test_interface.py
+++ b/src/maasserver/models/tests/test_interface.py
@@ -1396,6 +1396,28 @@ class TestUpdateInterfaceParentsOnSave(MAASServerTestCase):
         factory.make_Interface(self.iftype, parents=[parent1, parent2])
         self.assertIsNone(reload_object(static_ip))
 
+    def test_log_message(self):
+        node_config = factory.make_NodeConfig()
+        parent1 = factory.make_Interface(
+            iftype=INTERFACE_TYPE.PHYSICAL,
+            node_config=node_config,
+            name="parent1",
+        )
+        parent2 = factory.make_Interface(
+            iftype=INTERFACE_TYPE.PHYSICAL,
+            node_config=node_config,
+            name="parent2",
+        )
+        with FakeLogger("maas.interface") as maaslog:
+            child = factory.make_Interface(
+                self.iftype, parents=[parent1, parent2], name="child"
+            )
+        hostname = node_config.node.hostname
+        self.assertEqual(
+            f"parent2 (physical) on {hostname}: VLAN updated to match child ({self.iftype}) on {hostname} (vlan={child.vlan_id}).\n",
+            maaslog.output,
+        )
+
 
 class TestInterfaceUpdateNeighbour(MAASServerTestCase):
     """Tests for `Interface.update_neighbour`."""