Fixing call to hasManagedSaveImage

Fixes bug #1044090

hasManagedSaveImage is not implmented in the LXC libvirt driver, resulting
in the following error when a vm is deleted "Error from libvirt during saved
instance removal. Code=3 Error=this function is not supported by the
connection driver: virDomainHasManagedSaveImage"

This commit replaces the use of hasManagedSaveImage, managedSaveRemove and
undefine with undefineFlags which does the work of all 3 calls and is
implemented in versions of libvirt > 0.9.4. We also revert back to calling
undefine if undefineFlags raises an error.

Change-Id: Ib8d451aeff7767f835c3c1aab99ee4ab5e299852

nova/tests/fakelibvirt.py

@@ -69,6 +69,7 @@ VIR_DOMAIN_SHUTOFF = 5
 VIR_DOMAIN_CRASHED = 6
 
 VIR_DOMAIN_XML_SECURE = 1
+VIR_DOMAIN_UNDEFINE_MANAGED_SAVE = 1
 
 VIR_CPU_COMPARE_ERROR = -1
 VIR_CPU_COMPARE_INCOMPATIBLE = 0
@@ -276,6 +277,12 @@ class Domain(object):
     def undefine(self):
         self._connection._undefine(self)
 
+    def undefineFlags(self, flags):
+        self.undefine()
+        if flags & VIR_DOMAIN_UNDEFINE_MANAGED_SAVE:
+            if self.hasManagedSaveImage(0):
+                self.managedSaveRemove()
+
     def destroy(self):
         self._state = VIR_DOMAIN_SHUTOFF
         self._connection._mark_not_running(self)

nova/tests/test_libvirt.py

@@ -2160,12 +2160,33 @@ class LibvirtConnTestCase(test.TestCase):
         instance = db.instance_create(self.context, self.test_instance)
         conn.destroy(instance, {})
 
-    def test_destroy_saved(self):
-        """Ensure destroy calls managedSaveRemove for saved instance"""
+    def test_destroy(self):
+        """Ensure destroy calls virDomain.undefineFlags"""
         mock = self.mox.CreateMock(libvirt.virDomain)
         mock.destroy()
-        mock.hasManagedSaveImage(0).AndReturn(1)
-        mock.managedSaveRemove(0)
+        mock.undefineFlags(1).AndReturn(1)
+
+        self.mox.ReplayAll()
+
+        def fake_lookup_by_name(instance_name):
+            return mock
+
+        def fake_get_info(instance_name):
+            return {'state': power_state.SHUTDOWN}
+
+        conn = libvirt_driver.LibvirtDriver(False)
+        self.stubs.Set(conn, '_lookup_by_name', fake_lookup_by_name)
+        self.stubs.Set(conn, 'get_info', fake_get_info)
+        instance = {"name": "instancename", "id": "instanceid",
+                    "uuid": "875a8070-d0b9-4949-8b31-104d125c9a64"}
+        conn.destroy(instance, [])
+
+    def test_destroy_noflag(self):
+        """Ensure destroy calls virDomain.undefine
+        if mock.undefineFlags raises an error"""
+        mock = self.mox.CreateMock(libvirt.virDomain)
+        mock.destroy()
+        mock.undefineFlags(1).AndRaise(libvirt.libvirtError('Err'))
         mock.undefine()
 
         self.mox.ReplayAll()