+
−# -*- coding: UTF-8 -*-
+
−# Copyright (c) 2008 - 2010, Pascal Volk
+
−# See COPYING for distribution information.
+
−
+
−"""A small - r/o - wrapper class for Postfix' postconf."""
+
−
+
−import re
+
−from subprocess import Popen, PIPE
+
−
+
−import VirtualMailManager.constants.ERROR as ERR
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−from VirtualMailManager.errors import VMMError
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−
+
−RE_PC_PARAMS = """^\w+$"""
+
−RE_PC_VARIABLES = r"""\$\b\w+\b"""
+
−
+
−class Postconf(object):
+
−    __slots__ = ('__bin', '__val', '__varFinder')
+
−    def __init__(self, postconf_bin):
+
−        """Creates a new Postconf instance.
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−
+
−        Keyword arguments:
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−        postconf_bin -- absolute path to the Postfix postconf binary (str)
+
−        """
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−        self.__bin = postconf_bin
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−        self.__val = ''
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−        self.__varFinder = re.compile(RE_PC_VARIABLES)
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−
+
−    def read(self, parameter, expand_vars=True):
+
−        """Returns the parameters value.
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−
+
−        If expand_vars is True (default), all variables in the value will be
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−        expanded:
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−        e.g. mydestination -> mail.example.com, localhost.example.com, localhost
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−        Otherwise the value may contain one or more variables.
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−        e.g. mydestination -> $myhostname, localhost.$mydomain, localhost
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−
+
−        Keyword arguments:
+
−        parameter -- the name of a Postfix configuration parameter (str)
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−        expand_vars -- default True (bool)
+
−        """
+
−        if not re.match(RE_PC_PARAMS, parameter):
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−            raise VMMError(_(u'The value “%s” doesn\'t look like a valid\
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− postfix configuration parameter name.') % parameter, ERR.VMM_ERROR)
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−        self.__val = self.__read(parameter)
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−        if expand_vars:
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−            self.__expandVars()
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−        return self.__val
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−
+
−    def __expandVars(self):
+
−        while True:
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−            pvars = set(self.__varFinder.findall(self.__val))
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−            pvars_len = len(pvars)
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−            if pvars_len < 1:
+
−                break
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−            if pvars_len > 1:
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−                self.__expandMultiVars(self.__readMulti(pvars))
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−                continue
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−            pvars = pvars.pop()
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−            self.__val = self.__val.replace(pvars, self.__read(pvars[1:]))
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−
+
−    def __expandMultiVars(self, old_new):
+
−        for old, new in old_new.items():
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−            self.__val = self.__val.replace('$'+old, new)
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−
+
−    def __read(self, parameter):
+
−        out, err = Popen([self.__bin, '-h', parameter], stdout=PIPE,
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−                stderr=PIPE).communicate()
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−        if len(err):
+
−            raise VMMError(err.strip(), ERR.VMM_ERROR)
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−        return out.strip()
+
−
+
−    def __readMulti(self, parameters):
+
−        cmd = [self.__bin]
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−        for parameter in parameters:
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−            cmd.append(parameter[1:])
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−        out, err = Popen(cmd, stdout=PIPE, stderr=PIPE).communicate()
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−        if len(err):
+
−            raise VMMError(err.strip(), ERR.VMM_ERROR)
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−        par_val = {}
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−        for line in out.splitlines():
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−            par, val = line.split(' = ')
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−            par_val[par] = val
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−        return par_val
+
−