freeipa/ipapython/install/core.py
Martin Basti 697072cac9 Py3: do not use dict.iteritems()
Py3 does not support iter* methods, this commit replaces 2 occurencies
of iteritems() to items(). The dictionaries there are not big, this is
sufficient we do not need to use six.

https://fedorahosted.org/freeipa/ticket/5623

Reviewed-By: Martin Babinsky <mbabinsk@redhat.com>
2016-02-23 17:14:33 +01:00

596 lines
16 KiB
Python

#
# Copyright (C) 2015 FreeIPA Contributors see COPYING for license
#
"""
The framework core.
"""
import abc
import collections
import functools
import itertools
import sys
import six
from ipapython.ipa_log_manager import root_logger
from . import util
from .util import from_
__all__ = ['InvalidStateError', 'KnobValueError', 'Property', 'Knob',
'Configurable', 'Group', 'Component', 'Composite']
# Configurable states
_VALIDATE_PENDING = 'VALIDATE_PENDING'
_VALIDATE_RUNNING = 'VALIDATE_RUNNING'
_EXECUTE_PENDING = 'EXECUTE_PENDING'
_EXECUTE_RUNNING = 'EXECUTE_RUNNING'
_STOPPED = 'STOPPED'
_FAILED = 'FAILED'
_CLOSED = 'CLOSED'
_missing = object()
_counter = itertools.count()
@functools.cmp_to_key
def _class_key(a, b):
if a is b:
return 0
elif issubclass(a, b):
return -1
elif issubclass(b, a):
return 1
else:
return 0
class InvalidStateError(Exception):
pass
class KnobValueError(ValueError):
def __init__(self, name, message):
super(KnobValueError, self).__init__(message)
self.name = name
class PropertyBase(six.with_metaclass(util.InnerClassMeta, object)):
# shut up pylint
__outer_class__ = None
__outer_name__ = None
_order = None
@property
def default(self):
raise AttributeError('default')
def __init__(self, outer):
pass
def __get__(self, obj, obj_type):
while obj is not None:
try:
return obj.__dict__[self.__outer_name__]
except KeyError:
pass
obj = obj._get_fallback()
try:
return self.default
except AttributeError:
raise AttributeError(self.__outer_name__)
def __set__(self, obj, value):
try:
obj.__dict__[self.__outer_name__] = value
except KeyError:
raise AttributeError(self.__outer_name__)
def __delete__(self, obj):
try:
del obj.__dict__[self.__outer_name__]
except KeyError:
raise AttributeError(self.__outer_name__)
def Property(default=_missing):
class_dict = {}
if default is not _missing:
class_dict['default'] = default
return util.InnerClassMeta('Property', (PropertyBase,), class_dict)
class KnobBase(PropertyBase):
type = None
sensitive = False
deprecated = False
description = None
cli_name = None
cli_short_name = None
cli_aliases = None
cli_metavar = None
def __init__(self, outer):
self.outer = outer
def validate(self, value):
pass
@classmethod
def default_getter(cls, func):
@property
def default(self):
return func(self.outer)
cls.default = default
return cls
@classmethod
def validator(cls, func):
def validate(self, value):
func(self.outer, value)
super(cls, self).validate(value)
cls.validate = validate
return cls
def Knob(type_or_base, default=_missing, sensitive=_missing,
deprecated=_missing, description=_missing, cli_name=_missing,
cli_short_name=_missing, cli_aliases=_missing, cli_metavar=_missing):
class_dict = {}
class_dict['_order'] = next(_counter)
if (not isinstance(type_or_base, type) or
not issubclass(type_or_base, KnobBase)):
class_dict['type'] = type_or_base
type_or_base = KnobBase
if default is not _missing:
class_dict['default'] = default
if sensitive is not _missing:
class_dict['sensitive'] = sensitive
if deprecated is not _missing:
class_dict['deprecated'] = deprecated
if description is not _missing:
class_dict['description'] = description
if cli_name is not _missing:
class_dict['cli_name'] = cli_name
if cli_short_name is not _missing:
class_dict['cli_short_name'] = cli_short_name
if cli_aliases is not _missing:
class_dict['cli_aliases'] = cli_aliases
if cli_metavar is not _missing:
class_dict['cli_metavar'] = cli_metavar
return util.InnerClassMeta('Knob', (type_or_base,), class_dict)
class Configurable(six.with_metaclass(abc.ABCMeta, object)):
"""
Base class of all configurables.
FIXME: details of validate/execute, properties and knobs
"""
@classmethod
def properties(cls):
"""
Iterate over properties defined for the configurable.
"""
assert not hasattr(super(Configurable, cls), 'properties')
seen = set()
for owner_cls in cls.__mro__:
result = []
for name, prop_cls in owner_cls.__dict__.items():
if name in seen:
continue
seen.add(name)
if not isinstance(prop_cls, type):
continue
if not issubclass(prop_cls, PropertyBase):
continue
result.append((prop_cls._order, owner_cls, name))
result = sorted(result, key=lambda r: r[0])
for order, owner_cls, name in result:
yield owner_cls, name
@classmethod
def knobs(cls):
for owner_cls, name in cls.properties():
prop_cls = getattr(owner_cls, name)
if issubclass(prop_cls, KnobBase):
yield owner_cls, name
@classmethod
def group(cls):
assert not hasattr(super(Configurable, cls), 'group')
return None
def __init__(self, **kwargs):
"""
Initialize the configurable.
"""
self.log = root_logger
cls = self.__class__
for owner_cls, name in cls.properties():
if name.startswith('_'):
continue
prop_cls = getattr(owner_cls, name)
if not isinstance(prop_cls, type):
continue
if not issubclass(prop_cls, PropertyBase):
continue
try:
value = kwargs.pop(name)
except KeyError:
pass
else:
setattr(self, name, value)
for owner_cls, name in cls.knobs():
if name.startswith('_'):
continue
if not isinstance(self, owner_cls):
continue
value = getattr(self, name, None)
if value is None:
continue
prop_cls = getattr(owner_cls, name)
prop = prop_cls(self)
try:
prop.validate(value)
except KnobValueError:
raise
except ValueError as e:
raise KnobValueError(name, str(e))
if kwargs:
extra = sorted(kwargs)
raise TypeError(
"{0}() got {1} unexpected keyword arguments: {2}".format(
type(self).__name__,
len(extra),
', '.join(repr(name) for name in extra)))
self._reset()
def _reset(self):
assert not hasattr(super(Configurable, self), '_reset')
self.__state = _VALIDATE_PENDING
self.__gen = util.run_generator_with_yield_from(self._configure())
def _get_components(self):
assert not hasattr(super(Configurable, self), '_get_components')
raise TypeError("{0} is not composite".format(self))
def _get_fallback(self):
return None
@abc.abstractmethod
def _configure(self):
"""
Coroutine which defines the logic of the configurable.
"""
assert not hasattr(super(Configurable, self), '_configure')
self.__transition(_VALIDATE_RUNNING, _EXECUTE_PENDING)
while self.__state != _EXECUTE_RUNNING:
yield
def run(self):
"""
Run the configurable.
"""
self.validate()
if self.__state == _EXECUTE_PENDING:
self.execute()
def validate(self):
"""
Run the validation part of the configurable.
"""
for nothing in self._validator():
pass
def _validator(self):
"""
Coroutine which runs the validation part of the configurable.
"""
return self.__runner(_VALIDATE_PENDING, _VALIDATE_RUNNING)
def execute(self):
"""
Run the execution part of the configurable.
"""
for nothing in self._executor():
pass
def _executor(self):
"""
Coroutine which runs the execution part of the configurable.
"""
return self.__runner(_EXECUTE_PENDING, _EXECUTE_RUNNING)
def done(self):
"""
Return True if the configurable has finished.
"""
return self.__state in (_STOPPED, _FAILED, _CLOSED)
def run_until_executing(self, gen):
while self.__state != _EXECUTE_RUNNING:
try:
yield next(gen)
except StopIteration:
break
def __runner(self, pending_state, running_state):
self.__transition(pending_state, running_state)
step = lambda: next(self.__gen)
while True:
try:
step()
except StopIteration:
self.__transition(running_state, _STOPPED)
break
except GeneratorExit:
self.__transition(running_state, _CLOSED)
break
except BaseException:
exc_info = sys.exc_info()
try:
self._handle_exception(exc_info)
except BaseException:
raise
else:
break
finally:
self.__transition(running_state, _FAILED)
if self.__state != running_state:
break
try:
yield
except BaseException:
exc_info = sys.exc_info()
step = lambda: self.__gen.throw(*exc_info)
else:
step = lambda: next(self.__gen)
def _handle_exception(self, exc_info):
assert not hasattr(super(Configurable, self), '_handle_exception')
six.reraise(*exc_info)
def __transition(self, from_state, to_state):
if self.__state != from_state:
raise InvalidStateError(self.__state)
self.__state = to_state
class Group(Configurable):
@classmethod
def group(cls):
return cls
class ComponentMeta(util.InnerClassMeta, abc.ABCMeta):
pass
class ComponentBase(six.with_metaclass(ComponentMeta, Configurable)):
# shut up pylint
__outer_class__ = None
__outer_name__ = None
_order = None
@classmethod
def group(cls):
result = super(ComponentBase, cls).group()
if result is not None:
return result
else:
return cls.__outer_class__.group()
def __init__(self, parent, **kwargs):
self.__parent = parent
super(ComponentBase, self).__init__(**kwargs)
@property
def parent(self):
return self.__parent
def __get__(self, obj, obj_type):
obj.__dict__[self.__outer_name__] = self
return self
def _get_fallback(self):
return self.__parent
def _handle_exception(self, exc_info):
try:
super(ComponentBase, self)._handle_exception(exc_info)
except BaseException:
exc_info = sys.exc_info()
self.__parent._handle_exception(exc_info)
def Component(cls):
class_dict = {}
class_dict['_order'] = next(_counter)
return ComponentMeta('Component', (ComponentBase, cls), class_dict)
class Composite(Configurable):
"""
Configurable composed of any number of components.
Provides knobs of all child components.
"""
@classmethod
def properties(cls):
name_dict = {}
owner_dict = collections.OrderedDict()
for owner_cls, name in super(Composite, cls).properties():
name_dict[name] = owner_cls
owner_dict.setdefault(owner_cls, []).append(name)
for owner_cls, name in cls.components():
comp_cls = getattr(cls, name)
for owner_cls, name in comp_cls.knobs():
if hasattr(cls, name):
continue
try:
last_owner_cls = name_dict[name]
except KeyError:
name_dict[name] = owner_cls
owner_dict.setdefault(owner_cls, []).append(name)
else:
knob_cls = getattr(owner_cls, name)
last_knob_cls = getattr(last_owner_cls, name)
if issubclass(knob_cls, last_knob_cls):
name_dict[name] = owner_cls
owner_dict[last_owner_cls].remove(name)
owner_dict.setdefault(owner_cls, [])
if name not in owner_dict[owner_cls]:
owner_dict[owner_cls].append(name)
elif not issubclass(last_knob_cls, knob_cls):
raise TypeError("{0}.knobs(): conflicting definitions "
"of '{1}' in {2} and {3}".format(
cls.__name__,
name,
last_owner_cls.__name__,
owner_cls.__name__))
for owner_cls in sorted(owner_dict, key=_class_key):
for name in owner_dict[owner_cls]:
yield owner_cls, name
@classmethod
def components(cls):
assert not hasattr(super(Composite, cls), 'components')
seen = set()
for owner_cls in cls.__mro__:
result = []
for name, comp_cls in owner_cls.__dict__.items():
if name in seen:
continue
seen.add(name)
if not isinstance(comp_cls, type):
continue
if not issubclass(comp_cls, ComponentBase):
continue
result.append((comp_cls._order, owner_cls, name))
result = sorted(result, key=lambda r: r[0])
for order, owner_cls, name in result:
yield owner_cls, name
def __getattr__(self, name):
for owner_cls, knob_name in self.knobs():
if knob_name == name:
break
else:
raise AttributeError(name)
for component in self.__components:
if isinstance(component, owner_cls):
break
else:
raise AttributeError(name)
return getattr(component, name)
def _reset(self):
self.__components = list(self._get_components())
super(Composite, self)._reset()
def _get_components(self):
for owner_cls, name in self.components():
yield getattr(self, name)
def _configure(self):
validate = [(c, c._validator()) for c in self.__components]
while True:
new_validate = []
for child, validator in validate:
try:
next(validator)
except StopIteration:
pass
else:
new_validate.append((child, validator))
if not new_validate:
break
validate = new_validate
yield
if not self.__components:
return
yield from_(super(Composite, self)._configure())
execute = [(c, c._executor()) for c in self.__components
if not c.done()]
while True:
new_execute = []
for child, executor in execute:
try:
next(executor)
except StopIteration:
pass
else:
new_execute.append((child, executor))
if not new_execute:
break
execute = new_execute
yield