VMM{/Config}: reduced docstrings. Added doc to the repository.
# -*- coding: UTF-8 -*-
# Copyright (c) 2007 - 2010, Pascal Volk
# See COPYING for distribution information.
"""
VirtualMailManager.Config
VMM's configuration module for simplified configuration access.
"""
from ConfigParser import \
Error, MissingSectionHeaderError, NoOptionError, NoSectionError, \
ParsingError, RawConfigParser
from cStringIO import StringIO# TODO: move interactive stff to cli
from VirtualMailManager import exec_ok, get_unicode, is_dir
from VirtualMailManager.constants.ERROR import CONF_ERROR
from VirtualMailManager.Exceptions import VMMConfigException
class BadOptionError(Error):
"""Raised when a option isn't in the format 'section.option'."""
pass
class ConfigValueError(Error):
"""Raised when creating or validating of new values fails."""
pass
class NoDefaultError(Error):
"""Raised when the requested option has no default value."""
def __init__(self, section, option):
Error.__init__(self, 'Option %r in section %r has no default value' %
(option, section))
class LazyConfig(RawConfigParser):
"""The **lazy** derivate of the `RawConfigParser`.
There are two additional getters:
`pget()`
The polymorphic getter, which returns a option's value with the
appropriate type.
`dget()`
Like `LazyConfig.pget()`, but returns the option's default, from
`LazyConfig._cfg['sectionname']['optionname'].default`, if the
option is not configured in a ini-like configuration file.
`set()` differs from `RawConfigParser`'s `set()` method. `set()` takes
the `section` and `option` arguments combined to a single string in the
form "section.option".
"""
def __init__(self):
RawConfigParser.__init__(self)
self._modified = False
self._cfg = {
'sectionname': {
'optionname': LazyConfigOption(int, 1, self.getint)
}
}
"""sample _cfg dictionary. Create your own in your derived class."""
def bool_new(self, value):
"""Converts the string `value` into a `bool` and returns it.
| '1', 'on', 'yes' and 'true' will become `True`
| '0', 'off', 'no' and 'false' will become `False`
Throws a `ConfigValueError` for all other values, except bools.
"""
if isinstance(value, bool):
return value
if value.lower() in self._boolean_states:
return self._boolean_states[value.lower()]
else:
raise ConfigValueError(_(u"Not a boolean: '%s'") %
get_unicode(value))
def getboolean(self, section, option):
"""Returns the boolean value of the option, in the given section.
For a boolean True, the value must be set to '1', 'on', 'yes',
'true' or True. For a boolean False, the value must set to '0',
'off', 'no', 'false' or False.
If the option has another value assigned this method will raise a
ValueError.
"""
# if the setting was modified it may be still a boolean value lets see
tmp = self.get(section, option)
if isinstance(tmp, bool):
return tmp
return RawConfigParser.getboolean(self, section, option)
def _get_section_option(self, section_option):
"""splits ``section_option`` (section\ **.**\ option) in two parts
and returns them as list ``[section, option]``, if:
* it likes the format of ``section_option``
* the ``section`` is known
* the ``option`` is known
Else one of the following exceptions will be thrown:
* `BadOptionError`
* `NoSectionError`
* `NoOptionError`
"""
sect_opt = section_option.lower().split('.')
# TODO: cache it
if len(sect_opt) != 2:# do we need a regexp to check the format?
raise BadOptionError(
_(u"Bad format: '%s' - expected: section.option") %
get_unicode(section_option))
if not sect_opt[0] in self._cfg:
raise NoSectionError(sect_opt[0])
if not sect_opt[1] in self._cfg[sect_opt[0]]:
raise NoOptionError(sect_opt[1], sect_opt[0])
return sect_opt
def items(self, section):
"""returns an iterable that returns key, value ``tuples`` from the
given ``section``."""
if section in self._sections:# check if the section was parsed
d2 = self._sections[section]
elif not section in self._cfg:
raise NoSectionError(section)
else:
return ((k, self._cfg[section][k].default) \
for k in self._cfg[section].iterkeys())
# still here? Get defaults and merge defaults with configured setting
d = dict((k, self._cfg[section][k].default) \
for k in self._cfg[section].iterkeys())
d.update(d2)
if '__name__' in d:
del d['__name__']
return d.iteritems()
def dget(self, option):
"""Returns the value of the `option`.
If the option could not be found in the configuration file, the
configured default value, from ``LazyConfig._cfg`` will be
returned.
Arguments:
`option` : string
the configuration option in the form
"``section``\ **.**\ ``option``"
Throws a `NoDefaultError`, if no default value was passed to
`LazyConfigOption.__init__()` for the `option`.
"""
section, option = self._get_section_option(option)
try:
return self._cfg[section][option].getter(section, option)
except (NoSectionError, NoOptionError):
if not self._cfg[section][option].default is None:# may be False
return self._cfg[section][option].default
else:
raise NoDefaultError(section, option)
def pget(self, option):
"""Returns the value of the `option`."""
section, option = self._get_section_option(option)
return self._cfg[section][option].getter(section, option)
def set(self, option, value):
"""Set the `value` of the `option`.
Throws a `ValueError` if `value` couldn't be converted using
`LazyConfigOption.cls`"""
section, option = self._get_section_option(option)
val = self._cfg[section][option].cls(value)
if self._cfg[section][option].validate:
val = self._cfg[section][option].validate(val)
if not RawConfigParser.has_section(self, section):
self.add_section(section)
RawConfigParser.set(self, section, option, val)
self._modified = True
def has_section(self, section):
"""Checks if `section` is a known configuration section."""
return section.lower() in self._cfg
def has_option(self, option):
"""Checks if the option (section.option) is a known configuration
option."""
try:
self._get_section_option(option)
return True
except(BadOptionError, NoSectionError, NoOptionError):
return False
def sections(self):
"""Returns an iterator object for all configuration sections."""
return self._cfg.iterkeys()
class LazyConfigOption(object):
"""A simple container class for configuration settings.
`LazyConfigOption` instances are required by `LazyConfig` instances,
and instances of classes derived from `LazyConfig`, like the
`Config` class.
"""
__slots__ = ('__cls', '__default', '__getter', '__validate')
def __init__(self, cls, default, getter, validate=None):
"""Creates a new `LazyConfigOption` instance.
Arguments:
`cls` : type
The class/type of the option's value
`default`
Default value of the option. Use ``None`` if the option should not
have a default value.
`getter` : callable
A method's name of `RawConfigParser` and derived classes, to get a
option's value, e.g. `self.getint`.
`validate` : NoneType or a callable
None or any method, that takes one argument, in order to check the
value, when `LazyConfig.set()` is called.
"""
self.__cls = cls
if not default is None:# enforce the type of the default value
self.__default = self.__cls(default)
else:
self.__default = default
if not callable(getter):
raise TypeError('getter has to be a callable, got a %r' %
getter.__class__.__name__)
self.__getter = getter
if validate and not callable(validate):
raise TypeError('validate has to be callable or None, got a %r' %
validate.__class__.__name__)
self.__validate = validate
@property
def cls(self):
"""The class of the option's value e.g. `str`, `unicode` or `bool`"""
return self.__cls
@property
def default(self):
"""The option's default value, may be `None`"""
return self.__default
@property
def getter(self):
"""The getter method or function to get the option's value"""
return self.__getter
@property
def validate(self):
"""A method or function to validate the value"""
return self.__validate
class Config(LazyConfig):
"""This class is for reading vmm's configuration file."""
def __init__(self, filename):
"""Creates a new Config instance
Arguments:
`filename` : str
path to the configuration file
"""
LazyConfig.__init__(self)
self._cfgFileName = filename
self._cfgFile = None
self.__missing = {}
LCO = LazyConfigOption
bool_t = self.bool_new
self._cfg = {
'account': {
'delete_directory': LCO(bool_t, False, self.getboolean),
'directory_mode': LCO(int, 448, self.getint),
'disk_usage': LCO(bool_t, False, self.getboolean),
'password_length': LCO(int, 8, self.getint),
'random_password': LCO(bool_t, False, self.getboolean),
'imap' : LCO(bool_t, True, self.getboolean),
'pop3' : LCO(bool_t, True, self.getboolean),
'sieve': LCO(bool_t, True, self.getboolean),
'smtp' : LCO(bool_t, True, self.getboolean),
},
'bin': {
'dovecotpw': LCO(str, '/usr/sbin/dovecotpw', self.get, exec_ok),
'du': LCO(str, '/usr/bin/du', self.get, exec_ok),
'postconf': LCO(str, '/usr/sbin/postconf', self.get, exec_ok),
},
'database': {
'host': LCO(str, 'localhost', self.get),
'name': LCO(str, 'mailsys', self.get),
'pass': LCO(str, None, self.get),
'user': LCO(str, None, self.get),
},
'domain': {
'auto_postmaster': LCO(bool_t, True, self.getboolean),
'delete_directory': LCO(bool_t, False, self.getboolean),
'directory_mode': LCO(int, 504, self.getint),
'force_deletion': LCO(bool_t, False, self.getboolean),
},
'maildir': {
'folders': LCO(str, 'Drafts:Sent:Templates:Trash', self.get),
'name': LCO(str, 'Maildir', self.get),
},
'misc': {
'base_directory': LCO(str, '/srv/mail', self.get, is_dir),
'dovecot_version': LCO(int, 12, self.getint),
'gid_mail': LCO(int, 8, self.getint),
'password_scheme': LCO(str, 'CRAM-MD5', self.get,
self.known_scheme),
'transport': LCO(str, 'dovecot:', self.get),
},
}
def configure(self, sections):
raise NotImplementedError
def load(self):
"""Loads the configuration, read only.
Raises a VMMConfigException if the configuration syntax is invalid.
"""
try:
self._cfgFile = open(self._cfgFileName, 'r')
self.readfp(self._cfgFile)
except (MissingSectionHeaderError, ParsingError), e:
raise VMMConfigException(str(e), CONF_ERROR)
finally:
if self._cfgFile and not self._cfgFile.closed:
self._cfgFile.close()
def check(self):
"""Performs a configuration check.
Raises a VMMConfigException if the check fails.
"""
# TODO: There are only two settings w/o defaults.
# So there is no need for cStringIO
if not self.__chkCfg():
errmsg = StringIO()
errmsg.write(_(u'Missing options, which have no default value.\n'))
errmsg.write(_(u'Using configuration file: %s\n') %
self._cfgFileName)
for section, options in self.__missing.iteritems():
errmsg.write(_(u'* Section: %s\n') % section)
for option in options:
errmsg.write((u' %s\n') % option)
raise VMMConfigException(errmsg.getvalue(), CONF_ERROR)
def known_scheme(self, scheme):
"""Converts `scheme` to upper case and checks if is known by
Dovecot (listed in VirtualMailManager.SCHEMES).
Throws a `ConfigValueError` if the scheme is not listed in
VirtualMailManager.SCHEMES.
"""
scheme = scheme.upper()
# TODO: VMM.SCHEMES
def unicode(self, section, option):
"""Returns the value of the `option` from `section`, converted to
Unicode."""
return get_unicode(self.get(section, option))
def __chkCfg(self):
"""Checks all section's options for settings w/o a default value.
Returns `True` if everything is fine, else `False`."""
errors = False
for section in self._cfg.iterkeys():
missing = []
for option, value in self._cfg[section].iteritems():
if (value.default is None and
not RawConfigParser.has_option(self, section, option)):
missing.append(option)
errors = True
if missing:
self.__missing[section] = missing
return not errors