Add an example for the connection class

Also, change around the other examples to use the connection
example so there isn't duplication of code for session and
authentication.

Change-Id: I90dbcfac3eae0c792bd9c4eae071de7d81e1b27d

examples/authenticate.py

@@ -28,25 +28,12 @@ If you use the environment variables, authenticate with:
 import sys
 
 from examples import common
+from examples import connection
 from examples import transport
-from openstack import connection
 
 
 def make_authenticate(opts):
-    args = {
-        'auth_plugin': opts.auth_plugin,
-        'auth_url': opts.auth_url,
-        'project_name': opts.project_name,
-        'domain_name': opts.domain_name,
-        'project_domain_name': opts.project_domain_name,
-        'user_domain_name': opts.user_domain_name,
-        'user_name': opts.user_name,
-        'password': opts.password,
-        'verify': opts.verify,
-        'token': opts.token,
-    }
-    conn = connection.Connection(**args)
-    return conn.authenticator
+    return connection.make_connection(opts).session.authenticator
 
 
 def run_authenticate(opts):

examples/common.py

@@ -291,7 +291,7 @@ def option_parser():
     parser.add_argument(
         '--data',
         metavar='<data>',
-        default='{}',
+        default={},
         help='Json data for command.',
     )
     parser.add_argument(

examples/connection.py

@@ -0,0 +1,55 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+"""
+Example Connection Command
+
+Make sure you can authenticate before running this command.
+
+For example:
+    python -m examples.connection
+"""
+
+import sys
+
+from examples import common
+from openstack import connection
+
+
+def make_connection(opts):
+    args = {
+        'auth_plugin': opts.auth_plugin,
+        'auth_url': opts.auth_url,
+        'project_name': opts.project_name,
+        'domain_name': opts.domain_name,
+        'project_domain_name': opts.project_domain_name,
+        'user_domain_name': opts.user_domain_name,
+        'user_name': opts.user_name,
+        'password': opts.password,
+        'verify': opts.verify,
+        'token': opts.token,
+    }
+    conn = connection.Connection(preference=opts.user_preferences, **args)
+    return conn
+
+
+def run_connection(opts):
+    conn = make_connection(opts)
+    print("Connection: %s" % conn)
+    for flavor in conn.compute.list_flavors():
+        print(flavor.id + " " + flavor.name)
+    return
+
+
+if __name__ == "__main__":
+    opts = common.setup()
+    sys.exit(common.main(opts, run_connection))

examples/session.py

@@ -23,25 +23,12 @@ For example:
 import sys
 
 from examples import common
-from openstack import connection
+from examples import connection
 from openstack.identity import identity_service
 
 
 def make_session(opts):
-    args = {
-        'auth_plugin': opts.auth_plugin,
-        'auth_url': opts.auth_url,
-        'project_name': opts.project_name,
-        'domain_name': opts.domain_name,
-        'project_domain_name': opts.project_domain_name,
-        'user_domain_name': opts.user_domain_name,
-        'user_name': opts.user_name,
-        'password': opts.password,
-        'verify': opts.verify,
-        'token': opts.token,
-    }
-    conn = connection.Connection(preference=opts.user_preferences, **args)
-    return conn.session
+    return connection.make_connection(opts).session
 
 
 def run_session(opts):