Add power_on kwarg to ComputeDriver.spawn() method

For a cross-cell resize, the equivalent of the "finish_resize"
method on the destination compute is going to call the
driver spawn() method rather than the finish_migration()
method and needs to pass through the power_on value, similar
to finish_migration, so that when resizing a stopped server
it remains stopped once it is resized.

The finish_migration method in the driver behaves very similar
to spawn so the semantics are the same.

This change updates the spawn method signature for all in-tree
compute drivers but only implements the logic for the libvirt
driver as that is the only driver (currently) which supports
cross-cell resize (note the can_connect_volume method is also
necessary for cross-cell resize implementation in the driver).

Part of blueprint cross-cell-resize

Change-Id: I6929c588dd2e0e805f2e30b2e30d29967469d756

Author: mriedem

nova/tests/unit/virt/libvirt/test_driver.py

@@ -12857,7 +12857,7 @@ def fake_lookup(_uuid):
         mock_stat.assert_called_once_with(path)
         mock_get_size.assert_called_once_with(path)
 
-    def test_spawn_with_network_info(self):
+    def test_spawn_with_network_info(self, power_on=True):
         def fake_getLibVersion():
             return fakelibvirt.FAKE_LIBVIRT_VERSION
 
@@ -12918,19 +12918,29 @@ def fake_baselineCPU(cpu, flag):
         ):
             self.flags(instances_path=tmpdir)
 
-            hw_running = hardware.InstanceInfo(state=power_state.RUNNING)
-            mock_get_info.return_value = hw_running
+            if power_on:
+                hw_running = hardware.InstanceInfo(state=power_state.RUNNING)
+                mock_get_info.return_value = hw_running
+            else:
+                # Avoid a test timeout since _wait_for_boot is threaded.
+                mock_get_info.side_effect = Exception('do not call get_info')
             mock_build_device_metadata.return_value = None
 
             del mock_orig_libvirt.VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES
 
             drvr.spawn(self.context, instance, image_meta, [], 'herp', {},
-                       network_info=network_info)
+                       network_info=network_info, power_on=power_on)
 
-            mock_get_info.assert_called_once_with(instance)
+            if power_on:
+                mock_get_info.assert_called_once_with(instance)
+            else:
+                mock_get_info.assert_not_called()
             mock_build_device_metadata.assert_called_once_with(self.context,
                                                                instance)
 
+    def test_spawn_power_on_false(self):
+        self.test_spawn_with_network_info(power_on=False)
+
     # Methods called directly by spawn()
     @mock.patch.object(libvirt_driver.LibvirtDriver, '_get_guest_xml')
     @mock.patch.object(libvirt_driver.LibvirtDriver,

nova/virt/driver.py

@@ -342,11 +342,12 @@ def failed_spawn_cleanup(self, instance):
 
     def spawn(self, context, instance, image_meta, injected_files,
               admin_password, allocations, network_info=None,
-              block_device_info=None):
+              block_device_info=None, power_on=True):
         """Create a new instance/VM/domain on the virtualization platform.
 
         Once this successfully completes, the instance should be
-        running (power_state.RUNNING).
+        running (power_state.RUNNING) if ``power_on`` is True, else the
+        instance should be stopped (power_state.SHUTDOWN).
 
         If this fails, any partial instance should be completely
         cleaned up, and the virtualization platform should be in the state
@@ -366,6 +367,8 @@ def spawn(self, context, instance, image_meta, injected_files,
         :param network_info: instance network information
         :param block_device_info: Information about block devices to be
                                   attached to the instance.
+        :param power_on: True if the instance should be powered on, False
+                         otherwise
         """
         raise NotImplementedError()
 

nova/virt/fake.py

@@ -179,7 +179,7 @@ def unplug_vifs(self, instance, network_info):
 
     def spawn(self, context, instance, image_meta, injected_files,
               admin_password, allocations, network_info=None,
-              block_device_info=None):
+              block_device_info=None, power_on=True):
 
         if network_info:
             for vif in network_info:
@@ -191,7 +191,7 @@ def spawn(self, context, instance, image_meta, injected_files,
                 self._interfaces[vif['id']] = vif
 
         uuid = instance.uuid
-        state = power_state.RUNNING
+        state = power_state.RUNNING if power_on else power_state.SHUTDOWN
         flavor = instance.flavor
         self.resources.claim(
             vcpus=flavor.vcpus,
@@ -593,7 +593,7 @@ def finish_migration(self, context, migration, instance, disk_info,
         # claim resources and track the instance on this "hypervisor".
         self.spawn(context, instance, image_meta, injected_files,
                    admin_password, allocations,
-                   block_device_info=block_device_info)
+                   block_device_info=block_device_info, power_on=power_on)
 
     def confirm_migration(self, context, migration, instance, network_info):
         # Confirm migration cleans up the guest from the source host so just
@@ -764,15 +764,16 @@ class FakeRescheduleDriver(FakeDriver):
 
     def spawn(self, context, instance, image_meta, injected_files,
               admin_password, allocations, network_info=None,
-              block_device_info=None):
+              block_device_info=None, power_on=True):
         if not self.rescheduled.get(instance.uuid, False):
             # We only reschedule on the first time something hits spawn().
             self.rescheduled[instance.uuid] = True
             raise exception.ComputeResourcesUnavailable(
                 reason='FakeRescheduleDriver')
         super(FakeRescheduleDriver, self).spawn(
             context, instance, image_meta, injected_files,
-            admin_password, allocations, network_info, block_device_info)
+            admin_password, allocations, network_info, block_device_info,
+            power_on)
 
 
 class FakeRescheduleDriverWithNestedCustomResources(
@@ -786,7 +787,7 @@ class FakeBuildAbortDriver(FakeDriver):
     """
     def spawn(self, context, instance, image_meta, injected_files,
               admin_password, allocations, network_info=None,
-              block_device_info=None):
+              block_device_info=None, power_on=True):
         raise exception.BuildAbortException(
             instance_uuid=instance.uuid, reason='FakeBuildAbortDriver')
 
@@ -802,14 +803,15 @@ class FakeUnshelveSpawnFailDriver(FakeDriver):
     """
     def spawn(self, context, instance, image_meta, injected_files,
               admin_password, allocations, network_info=None,
-              block_device_info=None):
+              block_device_info=None, power_on=True):
         if instance.vm_state == vm_states.SHELVED_OFFLOADED:
             raise exception.VirtualInterfaceCreateException(
                 'FakeUnshelveSpawnFailDriver')
         # Otherwise spawn normally during the initial build.
         super(FakeUnshelveSpawnFailDriver, self).spawn(
             context, instance, image_meta, injected_files,
-            admin_password, allocations, network_info, block_device_info)
+            admin_password, allocations, network_info, block_device_info,
+            power_on)
 
 
 class FakeUnshelveSpawnFailDriverWithNestedCustomResources(

nova/virt/hyperv/driver.py

@@ -159,7 +159,7 @@ def list_instances(self):
 
     def spawn(self, context, instance, image_meta, injected_files,
               admin_password, allocations, network_info=None,
-              block_device_info=None):
+              block_device_info=None, power_on=True):
         self._vmops.spawn(context, instance, image_meta, injected_files,
                           admin_password, network_info, block_device_info)
 

nova/virt/ironic/driver.py

@@ -1112,7 +1112,7 @@ def _generate_configdrive(self, context, instance, node, network_info,
 
     def spawn(self, context, instance, image_meta, injected_files,
               admin_password, allocations, network_info=None,
-              block_device_info=None):
+              block_device_info=None, power_on=True):
         """Deploy an instance.
 
         :param context: The security context.
@@ -1129,6 +1129,8 @@ def spawn(self, context, instance, image_meta, injected_files,
         :param network_info: Instance network information.
         :param block_device_info: Instance block device
             information.
+        :param power_on: True if the instance should be powered on, False
+                         otherwise
         """
         LOG.debug('Spawn called for instance', instance=instance)
 

nova/virt/libvirt/driver.py

@@ -3199,7 +3199,7 @@ def poll_rebooting_instances(self, timeout, instances):
 
     def spawn(self, context, instance, image_meta, injected_files,
               admin_password, allocations, network_info=None,
-              block_device_info=None):
+              block_device_info=None, power_on=True):
         disk_info = blockinfo.get_disk_info(CONF.libvirt.virt_type,
                                             instance,
                                             image_meta,
@@ -3228,7 +3228,8 @@ def spawn(self, context, instance, image_meta, injected_files,
             context, xml, instance, network_info,
             block_device_info=block_device_info,
             post_xml_callback=gen_confdrive,
-            destroy_disks_on_failure=True)
+            destroy_disks_on_failure=True,
+            power_on=power_on)
         LOG.debug("Guest created on hypervisor", instance=instance)
 
         def _wait_for_boot():
@@ -3239,8 +3240,11 @@ def _wait_for_boot():
                 LOG.info("Instance spawned successfully.", instance=instance)
                 raise loopingcall.LoopingCallDone()
 
-        timer = loopingcall.FixedIntervalLoopingCall(_wait_for_boot)
-        timer.start(interval=0.5).wait()
+        if power_on:
+            timer = loopingcall.FixedIntervalLoopingCall(_wait_for_boot)
+            timer.start(interval=0.5).wait()
+        else:
+            LOG.info("Instance spawned successfully.", instance=instance)
 
     def _get_console_output_file(self, instance, console_log):
         bytes_to_read = MAX_CONSOLE_BYTES

nova/virt/powervm/driver.py

@@ -240,7 +240,7 @@ def update_provider_tree(self, provider_tree, nodename, allocations=None):
 
     def spawn(self, context, instance, image_meta, injected_files,
               admin_password, allocations, network_info=None,
-              block_device_info=None):
+              block_device_info=None, power_on=True):
         """Create a new instance/VM/domain on the virtualization platform.
 
         Once this successfully completes, the instance should be
@@ -264,6 +264,8 @@ def spawn(self, context, instance, image_meta, injected_files,
         :param network_info: instance network information
         :param block_device_info: Information about block devices to be
                                   attached to the instance.
+        :param power_on: True if the instance should be powered on, False
+                         otherwise
         """
         self._log_operation('spawn', instance)
         # Define the flow

nova/virt/vmwareapi/driver.py

@@ -537,7 +537,7 @@ def update_provider_tree(self, provider_tree, nodename, allocations=None):
 
     def spawn(self, context, instance, image_meta, injected_files,
               admin_password, allocations, network_info=None,
-              block_device_info=None):
+              block_device_info=None, power_on=True):
         """Create VM instance."""
         self._vmops.spawn(context, instance, image_meta, injected_files,
                           admin_password, network_info, block_device_info)

nova/virt/xenapi/driver.py

@@ -212,7 +212,7 @@ def _get_vgpu_info(self, allocations):
 
     def spawn(self, context, instance, image_meta, injected_files,
               admin_password, allocations, network_info=None,
-              block_device_info=None):
+              block_device_info=None, power_on=True):
         """Create VM instance."""
         vgpu_info = self._get_vgpu_info(allocations)
         self._vmops.spawn(context, instance, image_meta, injected_files,

nova/virt/zvm/driver.py

@@ -141,7 +141,7 @@ def get_info(self, instance, use_cache=True):
 
     def spawn(self, context, instance, image_meta, injected_files,
               admin_password, allocations, network_info=None,
-              block_device_info=None):
+              block_device_info=None, power_on=True):
 
         LOG.info("Spawning new instance %s on zVM hypervisor",
                  instance.name, instance=instance)