freeipa/ipalib/config.py

# Authors:
#   Martin Nagy <mnagy@redhat.com>
#
# Copyright (C) 2008  Red Hat
# see file 'COPYING' for use and warranty information
#
# This program 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; version 2 only
#
# This program 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 this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

from ConfigParser import SafeConfigParser, ParsingError
import types
import os

from errors import check_isinstance, raise_TypeError

DEFAULT_CONF='/etc/ipa/ipa.conf'


class Environment(object):
    """
    A mapping object used to store the environment variables.
    """

    def __init__(self):
        object.__setattr__(self, '_Environment__map', {})

    def __getattr__(self, name):
        """
        Return the attribute named ``name``.
        """
        return self[name]

    def __setattr__(self, name, value):
        """
        Set the attribute named ``name`` to ``value``.
        """
        self[name] = value

    def __delattr__(self, name):
        """
        Raise AttributeError (deletion is not allowed).
        """
        raise AttributeError('cannot del %s.%s' %
            (self.__class__.__name__, name)
        )

    def __getitem__(self, key):
        """
        Return the value corresponding to ``key``.
        """
        val = self.__map[key]
        if hasattr(val, 'get_value'):
            return val.get_value()
        else:
            return val

    def __setitem__(self, key, value):
        """
        Set the item at ``key`` to ``value``.
        """
        if key in self or hasattr(self, key):
            if hasattr(self.__map[key], 'set_value'):
                self.__map[key].set_value(value)
            else:
                raise AttributeError('cannot overwrite %s.%s' %
                            (self.__class__.__name__, key)
                )
        else:
            self.__map[key] = value

    def __contains__(self, key):
        """
        Return True if instance contains ``key``; otherwise return False.
        """
        return key in self.__map

    def __iter__(self):
        """
        Iterate through keys in ascending order.
        """
        for key in sorted(self.__map):
            yield key

    def update(self, new_vals, ignore_errors = False):
        assert type(new_vals) == dict
        for key, value in new_vals.iteritems():
            if ignore_errors:
                try:
                    self[key] = value
                except (AttributeError, KeyError):
                    pass
            else:
                self[key] = value

    def get(self, name, default=None):
        return self.__map.get(name, default)



def set_default_env(env):
    assert isinstance(env, Environment)

    default = dict(
        basedn = EnvProp(basestring, 'dc=example,dc=com'),
        container_accounts = EnvProp(basestring, 'cn=accounts'),
        container_user = EnvProp(basestring, 'cn=users,cn=accounts'),
        container_group = EnvProp(basestring, 'cn=groups,cn=accounts'),
        container_service = EnvProp(basestring, 'cn=services,cn=accounts'),
        domain = LazyProp(basestring, get_domain),
        interactive = EnvProp(bool, True),
        query_dns = EnvProp(bool, True),
        realm = LazyProp(basestring, get_realm),
        server_context = EnvProp(bool, True),
        server = LazyIter(basestring, get_servers),
        verbose = EnvProp(bool, False),
    )

    env.update(default)


class EnvProp(object):
    def __init__(self, type_, default, multi_value=False):
        if multi_value:
            if isinstance(default, tuple) and len(default):
                check_isinstance(default[0], type_, allow_none=True)
        self._type = type_
        self._default = default
        self._value = None
        self._multi_value = multi_value

    def get_value(self):
        if self._get() != None:
            return self._get()
        else:
            raise KeyError, 'Value not set'

    def set_value(self, value):
        if self._value != None:
            raise KeyError, 'Value already set'
        self._value = self._validate(value)

    def _get(self):
        if self._value != None:
            return self._value
        elif self._default != None:
            return self._default
        else:
            return None

    def _validate(self, value):
        if self._multi_value and isinstance(value, tuple):
            converted = []
            for val in value:
                converted.append(self._validate_value(val))
            return tuple(converted)
        else:
            return self._validate_value(value)

    def _validate_value(self, value):
        bool_true = ('true', 'yes', 'on')
        bool_false = ('false', 'no', 'off')

        if self._type == bool and isinstance(value, basestring):
            if value.lower() in bool_true:
                return True
            elif value.lower() in bool_false:
                return False
            else:
                raise raise_TypeError(value, bool, 'value')
        check_isinstance(value, self._type, 'value')
        return value


class LazyProp(EnvProp):
    def __init__(self, type_, func, default=None, multi_value=False):
        check_isinstance(func, types.FunctionType, 'func')
        self._func = func
        EnvProp.__init__(self, type_, default, multi_value)

    def get_value(self):
        if self._get() != None:
            return self._get()
        else:
            return self._func()


class LazyIter(LazyProp):
    def __init__(self, type_, func, default=None):
        LazyProp.__init__(self, type_, func, default, multi_value=True)

    def get_value(self):
        val = self._get()
        if val != None:
            if type(val) == tuple:
                for item in val:
                    yield item
            else:
                yield val
        for item in self._func():
            if not val or item not in val:
                yield item


# TODO: Make it possible to use var = 'foo, bar' without
#       turning it into ("'foo", "bar'")
def read_config(config_file=None):
    assert config_file == None or isinstance(config_file, (basestring, file))

    parser = SafeConfigParser()
    if config_file == None:
        files = [DEFAULT_CONF, os.path.expanduser('~/.ipa.conf')]
    else:
        files = [config_file]

    for f in files:
        try:
            if isinstance(f, file):
                parser.readfp(f)
            else:
                parser.read(f)
        except ParsingError:
            print "Can't read %s" % f

    ret = {}
    if parser.has_section('defaults'):
        for name, value in parser.items('defaults'):
            value = tuple(elem.strip() for elem in value.split(','))
            if len(value) == 1:
                value = value[0]
            ret[name] = value

    return ret


# these functions are here just to "emulate" dns resolving for now
def get_domain():
    return "ipatest.com"


def get_realm():
    return "IPATEST.COM"


def get_servers():
    yield "server.ipatest.com"
    yield "backup.ipatest.com"
    yield "fake.ipatest.com"