Check for image_meta in libvirt.driver.spawn

This adds check that image_meta exists in libvirt driver
spawn method. In case it doesn't the image shouldn't be
created.

part of libvirt driver support for blueprint rebuild-for-ha

DocImpact

Change-Id: I097c7cbfde96bcb21b4f06af4e5bac00440849c2
Co-authored-by: Oshrit Feder <oshritf@il.ibm.com>

2 files changed, 35 insertions, 1 deletions

diff --git a/nova/tests/test_libvirt.py b/nova/tests/test_libvirt.py
index 02578e888..362b53205 100644
--- a/nova/tests/test_libvirt.py
+++ b/nova/tests/test_libvirt.py
@@ -2451,6 +2451,38 @@ class LibvirtConnTestCase(test.TestCase):
             shutil.rmtree(os.path.join(CONF.instances_path,
                                        CONF.base_dir_name))
 
+    def test_spawn_without_image_meta(self):
+        self.create_image_called = False
+
+        def fake_none(*args, **kwargs):
+            return
+
+        def fake_create_image(*args, **kwargs):
+            self.create_image_called = True
+
+        def fake_get_info(instance):
+            return {'state': power_state.RUNNING}
+
+        instance_ref = self.test_instance
+        instance_ref['image_ref'] = 1
+        instance = db.instance_create(self.context, instance_ref)
+
+        conn = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
+        self.stubs.Set(conn, 'to_xml', fake_none)
+        self.stubs.Set(conn, '_create_image', fake_create_image)
+        self.stubs.Set(conn, '_create_domain_and_network', fake_none)
+        self.stubs.Set(conn, 'get_info', fake_get_info)
+
+        conn.spawn(self.context, instance, None, [], None)
+        self.assertFalse(self.create_image_called)
+
+        conn.spawn(self.context,
+                   instance,
+                   {'id': instance['image_ref']},
+                   [],
+                   None)
+        self.assertTrue(self.create_image_called)
+
     def test_get_console_output_file(self):
         fake_libvirt_utils.files['console.log'] = '01234567890'
 
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index bf45aad1d..cc2edfef1 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -1100,7 +1100,9 @@ class LibvirtDriver(driver.ComputeDriver):
               admin_password, network_info=None, block_device_info=None):
         xml = self.to_xml(instance, network_info, image_meta,
                           block_device_info=block_device_info)
-        self._create_image(context, instance, xml, network_info=network_info,
+        if image_meta:
+            self._create_image(context, instance, xml,
+                           network_info=network_info,
                            block_device_info=block_device_info,
                            files=injected_files,
                            admin_pass=admin_password)