Add API versioning support

* Specific versions supported are managed in XXXXXX.client.py with a
  mapping from version to client class.  This is based on the scheme
  that is included in novaclient; none of the other client libs have
  that capability.

Change-Id: I930b197f1189e7f52c3b0096e73e0773cf925542

3 files changed, 16 insertions, 6 deletions

diff --git a/openstackclient/common/clientmanager.py b/openstackclient/common/clientmanager.py
index e3f8588a..0a9f9102 100644
--- a/openstackclient/common/clientmanager.py
+++ b/openstackclient/common/clientmanager.py
@@ -54,9 +54,7 @@ class ClientManager(object):
                  tenant_name=None, tenant_id=None,
                  username=None, password=None,
                  region_name=None,
-                 identity_api_version=None,
-                 compute_api_version=None,
-                 image_api_version=None,
+                 api_version=None,
                  ):
         self._token = token
         self._url = url
@@ -66,9 +64,7 @@ class ClientManager(object):
         self._username = username
         self._password = password
         self._region_name = region_name
-        self._identity_api_version = identity_api_version
-        self._compute_api_version = compute_api_version
-        self._image_api_version = image_api_version
+        self._api_version = api_version
         self._service_catalog = None
 
         if not self._url:
diff --git a/openstackclient/common/exceptions.py b/openstackclient/common/exceptions.py
index 4b4a0fb4..aa070b37 100644
--- a/openstackclient/common/exceptions.py
+++ b/openstackclient/common/exceptions.py
@@ -39,6 +39,12 @@ class EndpointNotFound(Exception):
     pass
 
 
+class UnsupportedVersion(Exception):
+    """Indicates that the user is trying to use an unsupported
+       version of the API"""
+    pass
+
+
 class ClientException(Exception):
     """
     The base exception class for all exceptions this library raises.
diff --git a/openstackclient/common/utils.py b/openstackclient/common/utils.py
index fe0e5bcb..e0f35ad4 100644
--- a/openstackclient/common/utils.py
+++ b/openstackclient/common/utils.py
@@ -20,6 +20,7 @@ Common client utilities
 """
 
 import os
+import sys
 import uuid
 
 import prettytable
@@ -67,3 +68,10 @@ def env(*vars, **kwargs):
         if value:
             return value
     return kwargs.get('default', '')
+
+
+def import_class(import_str):
+    """Returns a class from a string including module and class."""
+    mod_str, _sep, class_str = import_str.rpartition('.')
+    __import__(mod_str)
+    return getattr(sys.modules[mod_str], class_str)