importing XenAPI module loaded late

3 files changed, 18 insertions, 5 deletions

diff --git a/nova/virt/xenapi/vm_utils.py b/nova/virt/xenapi/vm_utils.py
index 407acda6e..99d484ca2 100644
--- a/nova/virt/xenapi/vm_utils.py
+++ b/nova/virt/xenapi/vm_utils.py
@@ -20,15 +20,14 @@ their attributes like VDIs, VIFs, as well as their lookup functions.
 """
 
 import logging
-import XenAPI
 
 from twisted.internet import defer
 
 from nova import utils
 from nova.auth.manager import AuthManager
 from nova.compute import instance_types
-from nova.virt import images
 from nova.compute import power_state
+from nova.virt import images
 
 XENAPI_POWER_STATE = {
     'Halted': power_state.SHUTDOWN,
@@ -37,13 +36,17 @@ XENAPI_POWER_STATE = {
     'Suspended': power_state.SHUTDOWN,  # FIXME
     'Crashed': power_state.CRASHED}
 
+XenAPI = None
+
 
 class VMHelper():
     """
     The class that wraps the helper methods together.
     """
     def __init__(self):
-        return
+        global XenAPI
+        if XenAPI is None:
+            XenAPI = __import__('XenAPI')
 
     @classmethod
     @defer.inlineCallbacks
diff --git a/nova/virt/xenapi/vmops.py b/nova/virt/xenapi/vmops.py
index 3696782b3..d36cdaea5 100644
--- a/nova/virt/xenapi/vmops.py
+++ b/nova/virt/xenapi/vmops.py
@@ -19,7 +19,6 @@ Management class for VM-related functions (spawn, reboot, etc).
 """
 
 import logging
-import XenAPI
 
 from twisted.internet import defer
 
@@ -29,12 +28,17 @@ from nova.auth.manager import AuthManager
 from nova.virt.xenapi.network_utils import NetworkHelper
 from nova.virt.xenapi.vm_utils import VMHelper
 
+XenAPI = None
+
 
 class VMOps(object):
     """
     Management class for VM-related tasks
     """
     def __init__(self, session):
+        global XenAPI
+        if XenAPI is None:
+            XenAPI = __import__('XenAPI')
         self._session = session
 
     def list_instances(self):
diff --git a/nova/virt/xenapi_conn.py b/nova/virt/xenapi_conn.py
index a2eac4dc2..26b30bf92 100644
--- a/nova/virt/xenapi_conn.py
+++ b/nova/virt/xenapi_conn.py
@@ -49,7 +49,6 @@ reactor thread if the VM.get_by_name_label or VM.get_record calls block.
 
 import logging
 import xmlrpclib
-import XenAPI
 
 from twisted.internet import defer
 from twisted.internet import reactor
@@ -78,10 +77,17 @@ flags.DEFINE_float('xenapi_task_poll_interval',
                    '(Async.VM.start, etc).  Used only if '
                    'connection_type=xenapi.')
 
+XenAPI = None
+
 
 def get_connection(_):
     """Note that XenAPI doesn't have a read-only connection mode, so
     the read_only parameter is ignored."""
+    # This is loaded late so that there's no need to install this
+    # library when not using XenAPI.
+    global XenAPI
+    if XenAPI is None:
+        XenAPI = __import__('XenAPI')
     url = FLAGS.xenapi_connection_url
     username = FLAGS.xenapi_connection_username
     password = FLAGS.xenapi_connection_password