allow running cumin as a regular user

Change-Id: I8fd3e941aaff3ffbe5eaf1446b8212ba2e7062a9

cumin/cli.py

@@ -206,13 +206,12 @@ def parse_args(argv):
 
 
 def get_running_user():
-    """Ensure it's running as root and that the original user is detected and return it."""
-    if os.getenv('USER') != 'root':
-        raise cumin.CuminError('Insufficient privileges, run with sudo')
-    if os.getenv('SUDO_USER') in (None, 'root'):
-        raise cumin.CuminError('Unable to determine real user, logged in as root?')
-
-    return os.getenv('SUDO_USER')
+    """Ensure that the original user is detected and return it."""
+    if os.getenv('USER') == 'root':
+        if os.getenv('SUDO_USER') in (None, 'root'):
+            raise cumin.CuminError('Unable to determine real user, logged in as root?')
+        return os.getenv('SUDO_USER')
+    return os.getenv('USER')
 
 
 def setup_logging(filename, debug=False, trace=False):

cumin/tests/unit/test_cli.py

@@ -89,17 +89,16 @@ def test_target_batch_size_val_ko(value):
 
 
 def test_get_running_user():
-    """Unsufficient permissions or unknown user should raise CuminError and a proper user should be detected."""
-    env = {'USER': None, 'SUDO_USER': None}
-    with mock.patch('os.getenv', env.get):
-        with pytest.raises(CuminError, match='Insufficient privileges, run with sudo'):
-            cli.get_running_user()
-
+    """Unknown user should raise CuminError and a proper user should be detected."""
     env = {'USER': 'root', 'SUDO_USER': None}
     with mock.patch('os.getenv', env.get):
         with pytest.raises(CuminError, match='Unable to determine real user'):
             cli.get_running_user()
 
+    env = {'USER': 'user', 'SUDO_USER': None}
+    with mock.patch('os.getenv', env.get):
+        assert cli.get_running_user() == 'user'
+
     with mock.patch('os.getenv', _ENV.get):
         assert cli.get_running_user() == 'user'