Add os-client-config support for examples

Add the --os-cloud option to the examples so developers can
use OCC for examples.

Change-Id: Ieaa7568c83a7c3c87bd3524e078a35da23ffde92

examples/common.py

@@ -171,6 +171,14 @@ def option_parser():
     parser = argparse.ArgumentParser(
         description='A demonstration framework')
     # Global arguments
+    parser.add_argument(
+        '--os-cloud',
+        dest='cloud',
+        metavar='<cloud>',
+        default=env('OS_CLOUD', default=None),
+        help=('Cloud configuration from ' +
+              'https://pypi.python.org/pypi/os-client-config (Env: OS_CLOUD)')
+    )
     parser.add_argument(
         '--os-auth-plugin',
         dest='auth_plugin',

examples/connection.py

@@ -21,25 +21,17 @@ For example:
 
 import sys
 
+import os_client_config
+
 from examples import common
 from openstack import connection
 
 
 def make_connection(opts):
-    args = {
+    occ = os_client_config.OpenStackConfig()
-        'auth_plugin': opts.auth_plugin,
+    cloud = occ.get_one_cloud(opts.cloud, opts)
-        'auth_url': opts.auth_url,
+    auth = cloud.config['auth']
-        'project_name': opts.project_name,
+    conn = connection.Connection(preference=opts.user_preferences, **auth)
-        'domain_name': opts.domain_name,
-        'project_domain_name': opts.project_domain_name,
-        'user_domain_name': opts.user_domain_name,
-        'username': opts.username,
-        'password': opts.password,
-        'trust_id': opts.trust_id,
-        'verify': opts.verify,
-        'token': opts.token,
-    }
-    conn = connection.Connection(preference=opts.user_preferences, **args)
     return conn