cdist/cdist/core/cdist_object.py

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# -*- coding: utf-8 -*-
#
# 2011 Steven Armstrong (steven-cdist at armstrong.cc)
# 2011-2012 Nico Schottelius (nico-cdist at schottelius.org)
#
# This file is part of cdist.
#
# cdist 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 3 of the License, or
# (at your option) any later version.
#
# cdist 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 cdist. If not, see <http://www.gnu.org/licenses/>.
#
#
import logging
import os
import collections
import cdist
import cdist.core
from cdist.util import fsproperty
log = logging.getLogger(__name__)
OBJECT_MARKER = '.cdist'
class IllegalObjectIdError(cdist.Error):
def __init__(self, object_id, message=None):
self.object_id = object_id
self.message = message or 'Illegal object id'
def __str__(self):
return '%s: %s' % (self.message, self.object_id)
class CdistObject(object):
"""Represents a cdist object.
All interaction with objects in cdist should be done through this class.
Directly accessing an object through the file system from python code is
a bug.
"""
# Constants for use with Object.state
STATE_PREPARED = "prepared"
STATE_RUNNING = "running"
STATE_DONE = "done"
@classmethod
def list_objects(cls, object_base_path, type_base_path):
"""Return a list of object instances"""
for object_name in cls.list_object_names(object_base_path):
type_name, object_id = cls.split_name(object_name)
yield cls(cdist.core.CdistType(type_base_path, type_name), object_base_path, object_id=object_id)
@classmethod
def list_type_names(cls, object_base_path):
"""Return a list of type names"""
return os.listdir(object_base_path)
@classmethod
def list_object_names(cls, object_base_path):
"""Return a list of object names"""
for path, dirs, files in os.walk(object_base_path):
if OBJECT_MARKER in dirs:
yield os.path.relpath(path, object_base_path)
@staticmethod
def split_name(object_name):
"""split_name('__type_name/the/object_id') -> ('__type_name', 'the/object_id')
Split the given object name into it's type and object_id parts.
"""
type_name = object_name.split(os.sep)[0]
# FIXME: allow object without object_id? e.g. for singleton
object_id = os.sep.join(object_name.split(os.sep)[1:])
return type_name, object_id
@staticmethod
def join_name(type_name, object_id):
"""join_name('__type_name', 'the/object_id') -> __type_name/the/object_id'
Join the given type_name and object_id into an object name.
"""
return os.path.join(type_name, object_id)
def validate_object_id(self):
# FIXME: also check that there is no object ID when type is singleton?
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"""Validate the given object_id and raise IllegalObjectIdError if it's not valid.
"""
if self.object_id:
if OBJECT_MARKER in self.object_id.split(os.sep):
raise IllegalObjectIdError(self.object_id, 'object_id may not contain \'%s\'' % OBJECT_MARKER)
if '//' in self.object_id:
raise IllegalObjectIdError(self.object_id, 'object_id may not contain //')
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# If no object_id and type is not singleton => error out
if not self.object_id and not self.cdist_type.is_singleton:
raise IllegalObjectIdError(self.object_id,
"Missing object_id and type is not a singleton.")
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def __init__(self, cdist_type, base_path, object_id=None):
self.cdist_type = cdist_type # instance of Type
self.base_path = base_path
self.object_id = object_id
self.validate_object_id()
self.sanitise_object_id()
self.name = self.join_name(self.cdist_type.name, self.object_id)
self.path = os.path.join(self.cdist_type.path, self.object_id, OBJECT_MARKER)
self.absolute_path = os.path.join(self.base_path, self.path)
self.code_local_path = os.path.join(self.path, "code-local")
self.code_remote_path = os.path.join(self.path, "code-remote")
self.parameter_path = os.path.join(self.path, "parameter")
def object_from_name(self, object_name):
"""Convenience method for creating an object instance from an object name.
Mainly intended to create objects when resolving requirements.
e.g:
<CdistObject __foo/bar>.object_from_name('__other/object') -> <CdistObject __other/object>
"""
base_path = self.base_path
type_path = self.cdist_type.base_path
type_name, object_id = self.split_name(object_name)
cdist_type = self.cdist_type.__class__(type_path, type_name)
return self.__class__(cdist_type, base_path, object_id=object_id)
def __repr__(self):
return '<CdistObject %s>' % self.name
def __eq__(self, other):
"""define equality as 'name is the same'"""
return self.name == other.name
def __hash__(self):
return hash(self.name)
def __lt__(self, other):
return isinstance(other, self.__class__) and self.name < other.name
def sanitise_object_id(self):
"""
Remove leading and trailing slash (one only)
"""
# Allow empty object id for singletons
if self.object_id:
# Remove leading slash
if self.object_id[0] == '/':
self.object_id = self.object_id[1:]
# Remove trailing slash
if self.object_id[-1] == '/':
self.object_id = self.object_id[:-1]
# FIXME: still needed?
@property
def explorer_path(self):
"""Create and return the relative path to this objects explorers"""
# create absolute path
path = os.path.join(self.absolute_path, "explorer")
if not os.path.isdir(path):
os.mkdir(path)
# return relative path
return os.path.join(self.path, "explorer")
requirements = fsproperty.FileListProperty(lambda obj: os.path.join(obj.absolute_path, 'require'))
autorequire = fsproperty.FileListProperty(lambda obj: os.path.join(obj.absolute_path, 'autorequire'))
parameters = fsproperty.DirectoryDictProperty(lambda obj: os.path.join(obj.base_path, obj.parameter_path))
explorers = fsproperty.DirectoryDictProperty(lambda obj: os.path.join(obj.base_path, obj.explorer_path))
changed = fsproperty.FileBooleanProperty(lambda obj: os.path.join(obj.absolute_path, "changed"))
state = fsproperty.FileStringProperty(lambda obj: os.path.join(obj.absolute_path, "state"))
source = fsproperty.FileListProperty(lambda obj: os.path.join(obj.absolute_path, "source"))
code_local = fsproperty.FileStringProperty(lambda obj: os.path.join(obj.base_path, obj.code_local_path))
code_remote = fsproperty.FileStringProperty(lambda obj: os.path.join(obj.base_path, obj.code_remote_path))
@property
def exists(self):
"""Checks wether this cdist object exists on the file systems."""
return os.path.exists(self.absolute_path)
def create(self):
"""Create this cdist object on the filesystem.
"""
try:
os.makedirs(self.absolute_path, exist_ok=False)
absolute_parameter_path = os.path.join(self.base_path, self.parameter_path)
os.makedirs(absolute_parameter_path, exist_ok=False)
except EnvironmentError as error:
raise cdist.Error('Error creating directories for cdist object: %s: %s' % (self, error))