Check that list of upgraders without duplicates

The list of upgraders specified via command-line should not have duplicates
added test for incompatibility check

Change-Id: I24952a9e64034c3a98adbeae67a3c3a8dd7e1b67
Partial-Bug: #1495454

fuel_upgrade_system/fuel_upgrade/fuel_upgrade/cli.py

@@ -24,6 +24,7 @@ from fuel_upgrade.logger import configure_logger
 
 from fuel_upgrade import errors
 from fuel_upgrade import messages
+from fuel_upgrade import utils
 
 from fuel_upgrade.checker_manager import CheckerManager
 from fuel_upgrade.config import build_config
@@ -110,6 +111,13 @@ def parse_args(args):
                 )
             )
 
+    # check input systems have no duplicates
+    if len(rv.systems) != len(set(rv.systems)):
+        parser.error(
+            'the following systems are listed more than one times: "{0}"'
+            .format(', '.join(sorted(utils.get_non_unique(rv.systems))))
+        )
+
     return rv
 
 

fuel_upgrade_system/fuel_upgrade/fuel_upgrade/tests/test_cli.py

@@ -66,3 +66,31 @@ class TestAdminPassword(BaseTestCase):
                                      messages.no_password_provided):
             args = self.get_args(self.default_args)
             run_upgrade(args)
+
+
+class TestArgumentsParser(BaseTestCase):
+    default_args = ['--src', '/path']
+
+    def test_parse_list_of_systems(self):
+        systems = ['host-system', 'docker']
+        args = parse_args(systems + self.default_args)
+        self.assertEqual(systems, args.systems)
+
+    @mock.patch('argparse.ArgumentParser.error')
+    def test_error_if_systems_have_duplicates(self, error_mock):
+        parse_args(
+            ['host-system', 'docker', 'openstack', 'openstack', 'docker'] +
+            self.default_args
+        )
+        self.assertEqual(1, error_mock.call_count)
+        self.assertEqual(1, len(error_mock.call_args[0]))
+        self.assertIn('"docker, openstack"', error_mock.call_args[0][0])
+
+    @mock.patch('argparse.ArgumentParser.error')
+    def test_error_if_systems_are_incompatible(self, error_mock):
+        parse_args(
+            ['docker', 'docker-init'] + self.default_args
+        )
+        self.assertEqual(1, error_mock.call_count)
+        self.assertEqual(1, len(error_mock.call_args[0]))
+        self.assertIn('"docker-init, docker"', error_mock.call_args[0][0])

fuel_upgrade_system/fuel_upgrade/fuel_upgrade/tests/test_utils.py

@@ -22,6 +22,7 @@ import textwrap
 import urllib2
 
 import requests
+import six
 import yaml
 
 import mock
@@ -774,3 +775,14 @@ class TestHttpRetry(BaseTestCase):
         self.assertEqual(result, 'return value')
         self.called_times(method, 2)
         self.called_once(msleep)
+
+
+class TestGetNonUnique(BaseTestCase):
+    def test_get_duplicates(self):
+        self.assertItemsEqual([2, 3], utils.get_non_unique([2, 2, 2, 3, 3, 1]))
+
+    def test_empty_if_no_duplicates(self):
+        self.assertEqual([], list(utils.get_non_unique(six.moves.range(3))))
+
+    def test_empty_if_empty_input(self):
+        self.assertEqual([], list(utils.get_non_unique([])))

fuel_upgrade_system/fuel_upgrade/fuel_upgrade/utils.py

@@ -14,6 +14,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import collections
 from fnmatch import fnmatch
 import functools
 import glob
@@ -33,6 +34,7 @@ from distutils.version import StrictVersion
 
 from mako.template import Template
 import requests
+import six
 from six.moves import range
 import yaml
 
@@ -863,3 +865,12 @@ class http_retry(object):
                 time.sleep(self._interval)
 
         return _wrapped
+
+
+def get_non_unique(iterable):
+    """returns the non unique items without keeping the order."""
+
+    counter = collections.defaultdict(int)
+    for i in iterable:
+        counter[i] += 1
+    return [k for k, v in six.iteritems(counter) if v > 1]