Make tempestconf easier to use as an library

Make main and method responsible for parsing arguments more
modular, so that, it's easier to import them.

Now the argument parser can be imported to an other project,
we want to integrate to. This way, we achieve the CLI which
will be maintained at only one place.

Split main to two parts:
1. arguments handling
2. the rest of config_tempest, which can be importable
as an external module.

Change-Id: I3b1b9cbd05ccdb7ccae1b34211c4c955e831d32d

config_tempest/main.py

@@ -191,9 +191,9 @@ def set_options(conf, deployer_input, non_admin, overrides=[],
         conf.set("identity", "uri_v3", uri.replace("v2.0", "v3"))
 
 
-def parse_arguments():
+def get_arg_parser():
-    cloud_config = os_client_config.OpenStackConfig()
     parser = argparse.ArgumentParser(__doc__)
+    cloud_config = os_client_config.OpenStackConfig()
     cloud_config.register_argparse_arguments(parser, sys.argv)
     parser.add_argument('--create', action='store_true', default=False,
                         help='create default tempest resources')
@@ -238,15 +238,18 @@ def parse_arguments():
                                 configuration file.
                                 For example: --remove identity.username=myname
                                 --remove feature-enabled.api_ext=http,https""")
+    return parser
 
+
+def parse_arguments():
+    parser = get_arg_parser()
     args = parser.parse_args()
     if args.create and args.non_admin:
         raise Exception("Options '--create' and '--non-admin' cannot be used"
                         " together, since creating" " resources requires"
                         " admin rights")
     args.overrides = parse_overrides(args.overrides)
-    cloud = cloud_config.get_one_cloud(argparse=args)
+    return args
-    return cloud
 
 
 def parse_values_to_remove(options):
@@ -330,34 +333,59 @@ def set_cloud_config_values(non_admin, cloud_creds, conf):
             'Could not load some identity options from cloud config file')
 
 
-def main():
+def get_cloud_creds(args_namespace):
-    args = parse_arguments()
+    """Get cloud credentials based on argument namespace.
-    args.remove = parse_values_to_remove(args.remove)
+
-    set_logging(args.debug, args.verbose)
+    If args contains --os-cloud argument, the method returns cloud
+    credentials related to that cloud, otherwise, returns credentials
+    of the current cloud.
+
+    :type args_namespace: argparse.Namespace
+    :return: cloud credentials
+    :rtype: dict
+    EXAMPLE: {'username': 'demo', 'project_name': 'demo',
+              'user_domain_name': 'Default',
+              'auth_url': 'http://172.16.52.8:5000/v3',
+              'password': 'f0921edc3c2b4fc8', 'project_domain_name': 'Default'}
+    """
+    cloud = os_client_config.OpenStackConfig()
+    cloud = cloud.get_one_cloud(argparse=args_namespace)
+    cloud_creds = cloud.config.get('auth')
+    return cloud_creds
+
+
+def config_tempest(**kwargs):
+    # convert a list of remove values to a dict
+    remove = parse_values_to_remove(kwargs.get('remove', []))
+    set_logging(kwargs.get('debug', False), kwargs.get('verbose', False))
 
     conf = tempest_conf.TempestConf()
-    cloud_creds = args.config.get('auth')
+    set_options(conf, kwargs.get('deployer_input'),
-    set_options(conf, args.deployer_input, args.non_admin,
+                kwargs.get('non_admin', False),
-                args.overrides, args.test_accounts, cloud_creds)
+                kwargs.get('overrides', []), kwargs.get('test_accounts'),
+                kwargs.get('cloud_creds'))
 
-    credentials = Credentials(conf, not args.non_admin)
+    credentials = Credentials(conf, not kwargs.get('non_admin', False))
     clients = ClientManager(conf, credentials)
     services = Services(clients, conf, credentials)
 
-    if args.create and args.test_accounts is None:
+    if kwargs.get('create', False) and kwargs.get('test_accounts') is None:
         users = Users(clients.tenants, clients.roles, clients.users, conf)
         users.create_tempest_users(services.is_service('orchestration'))
-    flavors = Flavors(clients.flavors, args.create, conf)
+    flavors = Flavors(clients.flavors, kwargs.get('create', False), conf)
     flavors.create_tempest_flavors()
 
     image = services.get_service('image')
-    image.set_image_preferences(args.create, args.image,
+    image.set_image_preferences(kwargs.get('create', False),
-                                args.image_disk_format)
+                                kwargs.get('image_name', C.DEFAULT_IMAGE),
+                                kwargs.get('image_disk_format',
+                                           C.DEFAULT_IMAGE_FORMAT))
     image.create_tempest_images(conf)
 
     has_neutron = services.is_service("network")
     network = services.get_service("network")
-    network.create_tempest_networks(has_neutron, conf, args.network_id)
+    network.create_tempest_networks(has_neutron, conf,
+                                    kwargs.get('network_id'))
 
     services.set_service_availability()
     services.set_supported_api_versions()
@@ -365,20 +393,41 @@ def main():
     volume.check_volume_backup_service(conf, clients.volume_client,
                                        services.is_service("volumev3"))
     ceilometer.check_ceilometer_service(conf, clients.service_client)
-    boto.configure_boto(conf,
+    boto.configure_boto(conf, s3_service=services.get_service("s3"))
-                        s3_service=services.get_service("s3"))
     identity = services.get_service('identity')
     identity.configure_keystone_feature_flags(conf)
     configure_horizon(conf)
 
     # remove all unwanted values if were specified
-    if args.remove != {}:
+    if remove != {}:
-        LOG.info("Removing configuration: %s", str(args.remove))
+        LOG.info("Removing configuration: %s", str(remove))
-        conf.remove_values(args.remove)
+        conf.remove_values(remove)
-    LOG.info("Creating configuration file %s", os.path.abspath(args.out))
+    out_path = kwargs.get('out', 'etc/tempest.conf')
-    with open(args.out, 'w') as f:
+    LOG.info("Creating configuration file %s", os.path.abspath(out_path))
+    with open(out_path, 'w') as f:
         conf.write(f)
 
 
+def main():
+    args = parse_arguments()
+    cloud_creds = get_cloud_creds(args)
+    config_tempest(
+        create=args.create,
+        cloud_creds=cloud_creds,
+        debug=args.debug,
+        deployer_input=args.deployer_input,
+        image_name=args.image,
+        image_disk_format=args.image_disk_format,
+        network_id=args.network_id,
+        non_admin=args.non_admin,
+        os_cloud=args.os_cloud,
+        out=args.out,
+        overrides=args.overrides,
+        remove=args.remove,
+        test_accounts=args.test_accounts,
+        verbose=args.verbose
+    )
+
+
 if __name__ == "__main__":
     main()