Defer client imports

So we really weren't deferring the loading of client libs dadgummit,
do that for real where possible.  This shaves a couple of tenths off
the static import times.

Also defer as much import-time procesing as possible.  This is a little
ugly in api.auth but this also eliminates import of the auth plugins
until they are needed.

Change-Id: Ia11d4b9cf98231d37449103fc29101dc17afb009

1 files changed, 11 insertions, 9 deletions

diff --git a/openstackclient/volume/client.py b/openstackclient/volume/client.py
index 21072aeb..a7b64def 100644
--- a/openstackclient/volume/client.py
+++ b/openstackclient/volume/client.py
@@ -15,17 +15,8 @@
 
 import logging
 
-from cinderclient import extension
-from cinderclient.v1.contrib import list_extensions
-from cinderclient.v1 import volume_snapshots
-from cinderclient.v1 import volumes
-
 from openstackclient.common import utils
 
-# Monkey patch for v1 cinderclient
-volumes.Volume.NAME_ATTR = 'display_name'
-volume_snapshots.Snapshot.NAME_ATTR = 'display_name'
-
 LOG = logging.getLogger(__name__)
 
 DEFAULT_VOLUME_API_VERSION = '1'
@@ -38,6 +29,17 @@ API_VERSIONS = {
 
 def make_client(instance):
     """Returns a volume service client."""
+
+    # Defer client imports until we actually need them
+    from cinderclient import extension
+    from cinderclient.v1.contrib import list_extensions
+    from cinderclient.v1 import volume_snapshots
+    from cinderclient.v1 import volumes
+
+    # Monkey patch for v1 cinderclient
+    volumes.Volume.NAME_ATTR = 'display_name'
+    volume_snapshots.Snapshot.NAME_ATTR = 'display_name'
+
     volume_client = utils.get_client_class(
         API_NAME,
         instance._api_version[API_NAME],