'Iterate the name and status of the Flocker services known to SystemD.'

def flocker_services(self):

    service_pattern = '^(?P<service_name>flocker-.+)\\.service'
    for (service_name, service_status) in self.all_services():
        match = re.match(service_pattern, service_name)
        if match:
            service_name = match.group('service_name')
            if (service_status == 'enabled'):
                (yield (service_name, service_status))
