Handle endpoints with versions consistently

When using the cli the Glance client wraps the endpoint in a 'strip
version' function. This means that endpoints of the following forms can
both be used:

https://region-x.images.example.com:443/v1
https://region-x.images.example.com:443

When calling the client library directly (as Ceilometer does) however
only endpoints of the second form work. The cli and library should handle
the two cases consistently.

Addresses bug 1243276.

Change-Id: Ice7b581fee32540a7057ba47433a10166a3caed2

glanceclient/common/utils.py

@@ -17,6 +17,7 @@ from __future__ import print_function
 
 import errno
 import os
+import re
 import sys
 import uuid
 
@@ -315,3 +316,15 @@ def get_data_file(args):
         else:
             # (3) no image data provided
             return None
+
+
+def strip_version(endpoint):
+    """Strip version from the last component of endpoint if present."""
+    # Get rid of trailing '/' if present
+    if endpoint.endswith('/'):
+        endpoint = endpoint[:-1]
+    url_bits = endpoint.split('/')
+    # regex to match 'v1' or 'v2.0' etc
+    if re.match('v\d+\.?\d*', url_bits[-1]):
+        endpoint = '/'.join(url_bits[:-1])
+    return endpoint