92 lines
2.6 KiB
Python
92 lines
2.6 KiB
Python
"""
|
|
Copyright 2013 Rackspace, Inc.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
"""
|
|
|
|
import abc
|
|
|
|
import stevedore
|
|
import structlog
|
|
|
|
_global_manager = None
|
|
|
|
|
|
class HardwareSupport(object):
|
|
"""These are just guidelines to suggest values that might be returned by
|
|
calls to `evaluate_hardware_support`. No HardwareManager in mainline
|
|
teeth-agent will ever offer a value greater than `MAINLINE`. Service
|
|
Providers should feel free to return values greater than SERVICE_PROVIDER
|
|
to distinguish between additional levels of support.
|
|
"""
|
|
NONE = 0
|
|
GENERIC = 1
|
|
MAINLINE = 2
|
|
SERVICE_PROVIDER = 3
|
|
|
|
|
|
class HardwareManager(object):
|
|
@abc.abstractmethod
|
|
def evaluate_hardware_support(cls):
|
|
pass
|
|
|
|
@abc.abstractmethod
|
|
def get_primary_mac_address(self):
|
|
pass
|
|
|
|
@abc.abstractmethod
|
|
def get_os_install_device(self):
|
|
pass
|
|
|
|
|
|
class GenericHardwareManager(HardwareManager):
|
|
def evaluate_hardware_support(cls):
|
|
return HardwareSupport.GENERIC
|
|
|
|
def get_primary_mac_address(self):
|
|
return open('/sys/class/net/eth0/address', 'r').read().strip('\n')
|
|
|
|
def get_os_install_device(self):
|
|
return '/dev/sda'
|
|
|
|
|
|
def _compare_extensions(ext1, ext2):
|
|
mgr1 = ext1.obj
|
|
mgr2 = ext2.obj
|
|
return mgr1.evaluate_hardware_support() - mgr2.evaluate_hardware_support()
|
|
|
|
|
|
def get_manager():
|
|
global _global_manager
|
|
|
|
if not _global_manager:
|
|
log = structlog.get_logger()
|
|
extension_manager = stevedore.ExtensionManager(
|
|
namespace='teeth_agent.hardware_managers',
|
|
invoke_on_load=True)
|
|
|
|
# There will always be at least one extension available (the
|
|
# GenericHardwareManager).
|
|
preferred_extension = sorted(extension_manager, _compare_extensions)[0]
|
|
preferred_manager = preferred_extension.obj
|
|
|
|
if preferred_manager.evaluate_hardware_support() <= 0:
|
|
raise RuntimeError('No suitable HardwareManager could be found')
|
|
|
|
log.info('selected hardware manager',
|
|
manager_name=preferred_extension.entry_point_target)
|
|
|
|
_global_manager = preferred_manager
|
|
|
|
return _global_manager
|