2.0 KiB

Cinder Style Commandments

Cinder Specific Commandments

  • [N322] Ensure default arguments are not mutable.
  • [N323] Add check for explicit import of _() to ensure proper translation.
  • [C301] timeutils.utcnow() from oslo_utils should be used instead of
  • [C303] Ensure that there are no 'print()' statements are used in code that should be using LOG calls.
  • [C306] timeutils.strtime() must not be used (deprecated).
  • [C308] timeutils.isotime() must not be used (deprecated).
  • [C309] Unit tests should not perform logging.
  • [C310] Check for improper use of logging format arguments.
  • [C311] Check for proper naming and usage in option registration.
  • [C312] Validate that logs are not translated.
  • [C313] Check that assertTrue(value) is used and not assertEqual(True, value).
  • [C336] Must use a dict comprehension instead of a dict constructor with a sequence of key-value pairs.
  • [C337] Ensure the standard library mock modules is used and not the third party mock library that was needed for Python 2 support.
  • [C338] Log.warn is deprecated. Enforce use of LOG.warning.


  • Use 'raise' instead of 'raise e' to preserve original traceback or exception being reraised:

    except Exception as e:
        raise e  # BAD
    except Exception:
        raise  # OKAY

Creating Unit Tests

For every new feature, unit tests should be created that both test and (implicitly) document the usage of said feature. If submitting a patch for a bug that had no unit test, a new passing unit test should be added. If a submitted bug fix does have a unit test, be sure to add a new one that fails without the patch and passes with the patch.

For more information on creating unit tests and utilizing the testing infrastructure in OpenStack Cinder, please see