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1# substitutions.py2# Config file substitutions.3#4# Copyright (C) 2012-2016 Red Hat, Inc.5#6# This copyrighted material is made available to anyone wishing to use,7# modify, copy, or redistribute it subject to the terms and conditions of8# the GNU General Public License v.2, or (at your option) any later version.9# This program is distributed in the hope that it will be useful, but WITHOUT10# ANY WARRANTY expressed or implied, including the implied warranties of11# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General12# Public License for more details.  You should have received a copy of the13# GNU General Public License along with this program; if not, write to the14# Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA15# 02110-1301, USA.  Any Red Hat trademarks that are incorporated in the16# source code or documentation are not subject to the GNU General Public17# License and may only be used or replicated with the express permission of18# Red Hat, Inc.19#20 21import os22import re23 24import dnf25import dnf.exceptions26 27ENVIRONMENT_VARS_RE = re.compile(r'^DNF_VAR_[A-Za-z0-9_]+$')28 29class Substitutions(dict):30    # :api31 32    def __init__(self):33        super(Substitutions, self).__init__()34        self._update_from_env()35 36    def _update_from_env(self):37        numericvars = ['DNF%d' % num for num in range(0, 10)]38        for key, val in os.environ.items():39            if ENVIRONMENT_VARS_RE.match(key):40                self[key[8:]] = val  # remove "DNF_VAR_" prefix41            elif key in numericvars:42                self[key] = val43 44    def update_from_etc(self, installroot, varsdir=("/etc/yum/vars/", "/etc/dnf/vars/")):45        # :api46 47        for vars_path in varsdir:48            fsvars = []49            try:50                dir_fsvars = os.path.join(installroot, vars_path.lstrip('/'))51                fsvars = os.listdir(dir_fsvars)52            except OSError:53                continue54            for fsvar in fsvars:55                filepath = os.path.join(dir_fsvars, fsvar)56                val = None57                if os.path.isfile(filepath):58                    try:59                        with open(filepath) as fp:60                            val = fp.readline()61                        if val and val[-1] == '\n':62                            val = val[:-1]63                    except (OSError, IOError):64                        continue65                if val is not None:66                    self[fsvar] = val67