cdist/oo.py
Steven Armstrong 50a3ad7993 proof of concept object oriented aproach
Signed-off-by: Steven Armstrong <steven@icarus.ethz.ch>
2011-10-06 00:58:43 +02:00

242 lines
6.8 KiB
Python

import os
import tempfile
# FIXME: change these to match your environment
os.environ['__cdist_base_dir'] = '/home/sar/vcs/cdist'
# FIXME: testing against the cache, change path
os.environ['__cdist_out_dir'] = '/home/sar/vcs/cdist/cache/sans-asteven-02.ethz.ch/out'
'''
cd /path/to/dir/with/this/file
ipython
In [1]: import oo
In [2]: t = oo.Type('__mkfs')
In [3]: t.
t.base_dir t.is_install t.list_type_names t.name t.path
t.explorers t.is_singleton t.list_types t.optional_parameters t.required_parameters
In [3]: t.path
Out[3]: '/home/sar/vcs/cdist/conf/type/__mkfs'
In [4]: t.required_parameters
Out[4]: ['type']
In [5]: t.optional_parameters
Out[5]: ['device', 'options', 'blocks']
In [6]: t.is
t.is_install t.is_singleton
In [6]: t.is_singleton
Out[6]: False
In [7]: o = oo.Object(t, 'dev/sda1')
In [8]: o.
o.base_dir o.list_object_names o.list_type_names o.parameter o.qualified_name o.type
o.changed o.list_objects o.object_id o.path o.requirements
In [8]: o.pa
o.parameter o.path
In [8]: o.path
Out[8]: '/home/sar/vcs/cdist/cache/sans-asteven-02.ethz.ch/out/object/__mkfs/dev/sda1/.cdist'
In [9]: o.changed
Out[9]: False
In [10]: o.changed = True
In [11]: # creates /home/sar/vcs/cdist/cache/sans-asteven-02.ethz.ch/out/object/__mkfs/dev/sda1/.cdist/changed
In [12]: o.changed
Out[12]: True
In [13]: o.changed = False
In [14]: # removes /home/sar/vcs/cdist/cache/sans-asteven-02.ethz.ch/out/object/__mkfs/dev/sda1/.cdist/changed
In [15]:
'''
class Type(object):
@staticmethod
def base_dir():
"""Return the absolute path to the top level directory where types
are defined.
Requires the environment variable '__cdist_base_dir' to be set.
"""
return os.path.join(
os.environ['__cdist_base_dir'],
'conf',
'type'
)
@classmethod
def list_types(cls):
"""Return a list of type instances"""
for type_name in cls.list_type_names():
yield cls(type_name)
@classmethod
def list_type_names(cls):
"""Return a list of type names"""
return os.listdir(cls.base_dir())
def __init__(self, name):
self.name = name
self.__explorers = None
self.__required_parameters = None
self.__optional_parameters = None
def __repr__(self):
return '<Type name=%s>' % self.name
@property
def path(self):
return os.path.join(
self.base_dir(),
self.name
)
@property
def is_singleton(self):
"""Check whether a type is a singleton."""
return os.path.isfile(os.path.join(self.path, "singleton"))
@property
def is_install(self):
"""Check whether a type is used for installation (if not: for configuration)"""
return os.path.isfile(os.path.join(self.path, "install"))
@property
def explorers(self):
"""Return a list of available explorers"""
if not self.__explorers:
try:
self.__explorers = os.listdir(os.path.join(self.path, "explorer"))
except EnvironmentError as e:
# error ignored
self.__explorers = []
return self.__explorers
@property
def required_parameters(self):
"""Return a list of required parameters"""
if not self.__required_parameters:
parameters = []
try:
with open(os.path.join(self.path, "parameter", "required")) as fd:
for line in fd:
parameters.append(line.strip())
except EnvironmentError as e:
# error ignored
pass
finally:
self.__required_parameters = parameters
return self.__required_parameters
@property
def optional_parameters(self):
"""Return a list of optional parameters"""
if not self.__optional_parameters:
parameters = []
try:
with open(os.path.join(self.path, "parameter", "optional")) as fd:
for line in fd:
parameters.append(line.strip())
except EnvironmentError as e:
# error ignored
pass
finally:
self.__optional_parameters = parameters
return self.__optional_parameters
class Object(object):
@staticmethod
def base_dir():
"""Return the absolute path to the top level directory where objects
are defined.
Requires the environment variable '__cdist_out_dir' to be set.
"""
base_dir = os.path.join(
os.environ['__cdist_out_dir'],
'object'
)
# FIXME: should directory be created elsewhere?
if not os.path.isdir(base_dir):
os.mkdir(base_dir)
return base_dir
@classmethod
def list_objects(cls):
"""Return a list of object instances"""
for object_name in cls.list_object_names():
type_name = object_name.split(os.sep)[0]
object_id = os.sep.join(object_name.split(os.sep)[1:])
yield cls(Type(type_name), object_id=object_id)
@classmethod
def list_type_names(cls):
"""Return a list of type names"""
return os.listdir(cls.base_dir())
@classmethod
def list_object_names(cls):
"""Return a list of object names"""
for path, dirs, files in os.walk(cls.base_dir()):
# FIXME: use constant instead of string
if '.cdist' in dirs:
yield os.path.relpath(path, cls.base_dir())
def __init__(self, type, object_id=None, parameter=None, requirements=None):
self.type = type # instance of Type
self.object_id = object_id
self.qualified_name = os.path.join(self.type.name, self.object_id)
self.parameter = parameter or {}
self.requirements = requirements or []
def __repr__(self):
return '<Object %s>' % self.qualified_name
@property
def path(self):
return os.path.join(
self.base_dir(),
self.qualified_name,
'.cdist'
)
@property
def changed(self):
"""Check whether the object has been changed."""
return os.path.isfile(os.path.join(self.path, "changed"))
@changed.setter
def changed(self, value):
"""Change the objects changed status."""
path = os.path.join(self.path, "changed")
if value:
open(path, "w").close()
else:
try:
os.remove(path)
except EnvironmentError:
# ignore
pass
# FIXME: implement other properties/methods