Merge ~adam-collard/maas:lxd-power-debug into maas:master

[Adam Collard]

Add debug logging for LXD power state changes

[Anton Troyanov (troyanov)]

review: Approve

[MAAS Lander (maas-lander)]

LANDING
-b lxd-power-debug lp:~adam-collard/maas/+git/maas into -b master lp:~maas-committers/maas

STATUS: FAILED BUILD
LOG: http://maas-ci.internal:8080/job/maas/job/branch-tester/13016/consoleText

[MAAS Lander (maas-lander)]

UNIT TESTS
-b lxd-power-debug lp:~adam-collard/maas/+git/maas into -b master lp:~maas-committers/maas

STATUS: SUCCESS
COMMIT: 445dd044fb7e490e775a7f7f2293725563f167fe

review: Approve

diff --git a/src/provisioningserver/drivers/pod/lxd.py b/src/provisioningserver/drivers/pod/lxd.py
index 210afbd..a89329b 100644
--- a/src/provisioningserver/drivers/pod/lxd.py
+++ b/src/provisioningserver/drivers/pod/lxd.py
@@ -264,7 +264,9 @@ class LXDPodDriver(PodDriver):
     def power_on(self, pod_id: int, context: dict):
         """Power on LXD VM."""
         with self._get_machine(pod_id, context) as machine:
-            if LXD_VM_POWER_STATE[machine.status_code] == "off":
+            power_state = LXD_VM_POWER_STATE[machine.status_code]
+            maaslog.debug(f"power_on: {pod_id} is {power_state}")
+            if power_state == "off":
                 machine.start()
 
     @asynchronous
@@ -272,7 +274,9 @@ class LXDPodDriver(PodDriver):
     def power_off(self, pod_id: int, context: dict):
         """Power off LXD VM."""
         with self._get_machine(pod_id, context) as machine:
-            if LXD_VM_POWER_STATE[machine.status_code] == "on":
+            power_state = LXD_VM_POWER_STATE[machine.status_code]
+            maaslog.debug(f"power_off: {pod_id} is {power_state}")
+            if power_state == "on":
                 machine.stop()
 
     @asynchronous
diff --git a/src/provisioningserver/drivers/pod/tests/test_lxd.py b/src/provisioningserver/drivers/pod/tests/test_lxd.py
index 45f0951..ea98268 100644
--- a/src/provisioningserver/drivers/pod/tests/test_lxd.py
+++ b/src/provisioningserver/drivers/pod/tests/test_lxd.py
@@ -581,17 +581,43 @@ class TestLXDPodDriver(MAASTestCase):
 
     @inlineCallbacks
     def test_power_on(self):
+        pod_id = factory.make_name("pod_id")
         machine = self.fake_lxd.virtual_machines.get.return_value
         machine.status_code = 110
-        yield self.driver.power_on(None, self.make_context())
+        mock_log = self.patch(lxd_module, "maaslog")
+        yield self.driver.power_on(pod_id, self.make_context())
         machine.start.assert_called_once_with()
+        mock_log.debug.assert_called_once_with(f"power_on: {pod_id} is off")
+
+    @inlineCallbacks
+    def test_power_on_noop_if_on(self):
+        pod_id = factory.make_name("pod_id")
+        machine = self.fake_lxd.virtual_machines.get.return_value
+        machine.status_code = 103
+        mock_log = self.patch(lxd_module, "maaslog")
+        yield self.driver.power_on(pod_id, self.make_context())
+        machine.start.assert_not_called()
+        mock_log.debug.assert_called_once_with(f"power_on: {pod_id} is on")
 
     @inlineCallbacks
     def test_power_off(self):
+        pod_id = factory.make_name("pod_id")
         machine = self.fake_lxd.virtual_machines.get.return_value
         machine.status_code = 103
-        yield self.driver.power_off(None, self.make_context())
+        mock_log = self.patch(lxd_module, "maaslog")
+        yield self.driver.power_off(pod_id, self.make_context())
         machine.stop.assert_called_once_with()
+        mock_log.debug.assert_called_once_with(f"power_off: {pod_id} is on")
+
+    @inlineCallbacks
+    def test_power_off_noop_if_off(self):
+        pod_id = factory.make_name("pod_id")
+        machine = self.fake_lxd.virtual_machines.get.return_value
+        machine.status_code = 110
+        mock_log = self.patch(lxd_module, "maaslog")
+        yield self.driver.power_off(pod_id, self.make_context())
+        machine.stop.assert_not_called()
+        mock_log.debug.assert_called_once_with(f"power_off: {pod_id} is off")
 
     @inlineCallbacks
     def test_power_query(self):