'The version of the OS package of Flocker to install.'

def os_version(self):

    if self.version:
        rpm_version = make_rpm_version(self.version)
        os_version = ('%s-%s' % (rpm_version.version, rpm_version.release))
        if os_version.endswith('.dirty'):
            os_version = os_version[:(- len('.dirty'))]
    else:
        os_version = None
    return os_version
