Source code for lago.plugins.service

#
# Copyright 2016 Red Hat, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
#
# Refer to the README and COPYING files for full details of the license
#

from __future__ import absolute_import
"""
Service Plugin
=================

This plugins are used in order to manage services in the vms

"""
from abc import (abstractmethod, abstractproperty, ABCMeta)

from enum import Enum
from six import with_metaclass

from . import Plugin


[docs]class ServiceState(Enum): #: This state corresponds to a service that is not available in the domain MISSING = 0 INACTIVE = 1 ACTIVE = 2
[docs]class ServicePlugin(with_metaclass(ABCMeta, Plugin)): def __init__(self, vm, name): self._vm = vm self._name = name
[docs] @abstractmethod def state(self): """ Check the current status of the service Returns: ServiceState: Which state the service is at right now """ pass
[docs] @abstractmethod def _request_start(self): """ Low level implementation of the service start request, used by the `func:start` method Returns: bool: True if the service succeeded to start, False otherwise """ pass
[docs] @abstractmethod def _request_stop(self): """ Low level implementation of the service stop request, used by the `func:stop` method Returns: bool: True if the service succeeded to stop, False otherwise """ pass
@abstractproperty def BIN_PATH(self): """ Path to the binary used to manage services in the vm, will be checked for existence when trying to decide if the serviece is supported on the VM (see `func:is_supported`). Returns: str: Full path to the binary insithe the domain """ pass
[docs] def exists(self): return self.state() != ServiceState.MISSING
[docs] def alive(self): return self.state() == ServiceState.ACTIVE
[docs] def start(self): state = self.state() if state == ServiceState.MISSING: raise RuntimeError('Service %s not present' % self._name) elif state == ServiceState.ACTIVE: return if self._request_start(): raise RuntimeError('Failed to start service')
[docs] def stop(self): state = self.state() if state == ServiceState.MISSING: raise RuntimeError('Service %s not present' % self._name) elif state == ServiceState.INACTIVE: return if self._request_stop(): raise RuntimeError('Failed to stop service')
[docs] @classmethod def is_supported(cls, vm): return vm.ssh(['test', '-e', cls.BIN_PATH]).code == 0