Merge "Allows xenapi 'lookup' to look for rescue mode VMs"

2 files changed, 36 insertions, 2 deletions

diff --git a/nova/tests/virt/xenapi/test_vm_utils.py b/nova/tests/virt/xenapi/test_vm_utils.py
index a021bc734..bba704ed9 100644
--- a/nova/tests/virt/xenapi/test_vm_utils.py
+++ b/nova/tests/virt/xenapi/test_vm_utils.py
@@ -63,6 +63,33 @@ class LookupTestCase(test.TestCase):
                           vm_utils.lookup,
                           self.session, self.name_label)
 
+    def test_rescue_none(self):
+        self.session.call_xenapi(
+            "VM.get_by_name_label", self.name_label + '-rescue').AndReturn([])
+        self._do_mock(['x'])
+        result = vm_utils.lookup(self.session, self.name_label,
+                                 check_rescue=True)
+        self.assertEqual('x', result)
+
+    def test_rescue_found(self):
+        self.session.call_xenapi(
+            "VM.get_by_name_label",
+            self.name_label + '-rescue').AndReturn(['y'])
+        self.mox.ReplayAll()
+        result = vm_utils.lookup(self.session, self.name_label,
+                                 check_rescue=True)
+        self.assertEqual('y', result)
+
+    def test_rescue_too_many(self):
+        self.session.call_xenapi(
+            "VM.get_by_name_label",
+            self.name_label + '-rescue').AndReturn(['a', 'b', 'c'])
+        self.mox.ReplayAll()
+        self.assertRaises(exception.InstanceExists,
+                          vm_utils.lookup,
+                          self.session, self.name_label,
+                          check_rescue=True)
+
 
 class GenerateConfigDriveTestCase(test.TestCase):
     def test_no_admin_pass(self):
diff --git a/nova/virt/xenapi/vm_utils.py b/nova/virt/xenapi/vm_utils.py
index 67b6a9cc0..e569216c8 100644
--- a/nova/virt/xenapi/vm_utils.py
+++ b/nova/virt/xenapi/vm_utils.py
@@ -1394,8 +1394,15 @@ def lookup_vm_vdis(session, vm_ref):
     return vdi_refs
 
 
-def lookup(session, name_label):
-    """Look the instance up and return it if available."""
+def lookup(session, name_label, check_rescue=False):
+    """Look the instance up and return it if available.
+    :param check_rescue: if True will return the 'name'-rescue vm if it
+                         exists, instead of just 'name'
+    """
+    if check_rescue:
+        result = lookup(session, name_label + '-rescue', False)
+        if result:
+            return result
     vm_refs = session.call_xenapi("VM.get_by_name_label", name_label)
     n = len(vm_refs)
     if n == 0: