Current File : //usr/lib/python3.6/site-packages/dnf/plugin.py
# plugin.py
# The interface for building DNF plugins.
#
# Copyright (C) 2012-2016 Red Hat, Inc.
#
# This copyrighted material is made available to anyone wishing to use,
# modify, copy, or redistribute it subject to the terms and conditions of
# the GNU General Public License v.2, or (at your option) any later version.
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY expressed or implied, including the implied warranties 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., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA. Any Red Hat trademarks that are incorporated in the
# source code or documentation are not subject to the GNU General Public
# License and may only be used or replicated with the express permission of
# Red Hat, Inc.
#
from __future__ import absolute_import
from __future__ import print_function
from __future__ import unicode_literals
import fnmatch
import glob
import importlib
import inspect
import logging
import operator
import os
import sys
import traceback
import libdnf
import dnf.logging
import dnf.pycomp
import dnf.util
from dnf.i18n import _
logger = logging.getLogger('dnf')
DYNAMIC_PACKAGE = 'dnf.plugin.dynamic'
class Plugin(object):
"""The base class custom plugins must derive from. #:api"""
name = '<invalid>'
config_name = None
@classmethod
def read_config(cls, conf):
# :api
parser = libdnf.conf.ConfigParser()
name = cls.config_name if cls.config_name else cls.name
files = ['%s/%s.conf' % (path, name) for path in conf.pluginconfpath]
for file in files:
if os.path.isfile(file):
try:
parser.read(file)
except Exception as e:
raise dnf.exceptions.ConfigError(_("Parsing file failed: %s") % str(e))
return parser
def __init__(self, base, cli):
# :api
self.base = base
self.cli = cli
def pre_config(self):
# :api
pass
def config(self):
# :api
pass
def resolved(self):
# :api
pass
def sack(self):
# :api
pass
def pre_transaction(self):
# :api
pass
def transaction(self):
# :api
pass
class Plugins(object):
def __init__(self):
self.plugin_cls = []
self.plugins = []
def __del__(self):
self._unload()
def _caller(self, method):
for plugin in self.plugins:
try:
getattr(plugin, method)()
except dnf.exceptions.Error:
raise
except Exception:
exc_type, exc_value, exc_traceback = sys.exc_info()
except_list = traceback.format_exception(exc_type, exc_value, exc_traceback)
logger.critical(''.join(except_list))
def _check_enabled(self, conf, enable_plugins):
"""Checks whether plugins are enabled or disabled in configuration files
and removes disabled plugins from list"""
for plug_cls in self.plugin_cls[:]:
name = plug_cls.name
if any(fnmatch.fnmatch(name, pattern) for pattern in enable_plugins):
continue
parser = plug_cls.read_config(conf)
# has it enabled = False?
disabled = (parser.has_section('main')
and parser.has_option('main', 'enabled')
and not parser.getboolean('main', 'enabled'))
if disabled:
self.plugin_cls.remove(plug_cls)
def _load(self, conf, skips, enable_plugins):
"""Dynamically load relevant plugin modules."""
if DYNAMIC_PACKAGE in sys.modules:
raise RuntimeError("load_plugins() called twice")
sys.modules[DYNAMIC_PACKAGE] = package = dnf.pycomp.ModuleType(DYNAMIC_PACKAGE)
package.__path__ = []
files = _get_plugins_files(conf.pluginpath, skips, enable_plugins)
_import_modules(package, files)
self.plugin_cls = _plugin_classes()[:]
self._check_enabled(conf, enable_plugins)
if len(self.plugin_cls) > 0:
names = sorted(plugin.name for plugin in self.plugin_cls)
logger.debug(_('Loaded plugins: %s'), ', '.join(names))
def _run_pre_config(self):
self._caller('pre_config')
def _run_config(self):
self._caller('config')
def _run_init(self, base, cli=None):
for p_cls in self.plugin_cls:
plugin = p_cls(base, cli)
self.plugins.append(plugin)
def run_sack(self):
self._caller('sack')
def run_resolved(self):
self._caller('resolved')
def run_pre_transaction(self):
self._caller('pre_transaction')
def run_transaction(self):
self._caller('transaction')
def _unload(self):
if DYNAMIC_PACKAGE in sys.modules:
logger.log(dnf.logging.DDEBUG, 'Plugins were unloaded.')
del sys.modules[DYNAMIC_PACKAGE]
def unload_removed_plugins(self, transaction):
"""
Unload plugins that were removed in the `transaction`.
"""
if not transaction.remove_set:
return
# gather all installed plugins and their files
plugins = dict()
for plugin in self.plugins:
plugins[inspect.getfile(plugin.__class__)] = plugin
# gather all removed files that are plugin files
plugin_files = set(plugins.keys())
erased_plugin_files = set()
for pkg in transaction.remove_set:
erased_plugin_files.update(plugin_files.intersection(pkg.files))
if not erased_plugin_files:
return
# check whether removed plugin file is added at the same time (upgrade of a plugin)
for pkg in transaction.install_set:
erased_plugin_files.difference_update(pkg.files)
# unload plugins that were removed in transaction
for plugin_file in erased_plugin_files:
self.plugins.remove(plugins[plugin_file])
def _plugin_classes():
return Plugin.__subclasses__()
def _import_modules(package, py_files):
for fn in py_files:
path, module = os.path.split(fn)
package.__path__.append(path)
(module, ext) = os.path.splitext(module)
name = '%s.%s' % (package.__name__, module)
try:
module = importlib.import_module(name)
except Exception as e:
logger.error(_('Failed loading plugin "%s": %s'), module, e)
logger.log(dnf.logging.SUBDEBUG, '', exc_info=True)
def _get_plugins_files(paths, disable_plugins, enable_plugins):
plugins = []
disable_plugins = set(disable_plugins)
enable_plugins = set(enable_plugins)
pattern_enable_found = set()
pattern_disable_found = set()
for p in paths:
for fn in glob.glob('%s/*.py' % p):
(plugin_name, dummy) = os.path.splitext(os.path.basename(fn))
matched = True
enable_pattern_tested = False
for pattern_skip in disable_plugins:
if _plugin_name_matches_pattern(plugin_name, pattern_skip):
pattern_disable_found.add(pattern_skip)
matched = False
for pattern_enable in enable_plugins:
if _plugin_name_matches_pattern(plugin_name, pattern_enable):
matched = True
pattern_enable_found.add(pattern_enable)
enable_pattern_tested = True
if not enable_pattern_tested:
for pattern_enable in enable_plugins:
if _plugin_name_matches_pattern(plugin_name, pattern_enable):
pattern_enable_found.add(pattern_enable)
if matched:
plugins.append(fn)
enable_not_found = enable_plugins.difference(pattern_enable_found)
if enable_not_found:
logger.warning(_("No matches found for the following enable plugin patterns: {}").format(
", ".join(sorted(enable_not_found))))
disable_not_found = disable_plugins.difference(pattern_disable_found)
if disable_not_found:
logger.warning(_("No matches found for the following disable plugin patterns: {}").format(
", ".join(sorted(disable_not_found))))
return plugins
def _plugin_name_matches_pattern(plugin_name, pattern):
"""
Checks plugin name matches the pattern.
The alternative plugin name using dashes instead of underscores is tried
in case of original name is not matched.
(see https://bugzilla.redhat.com/show_bug.cgi?id=1980712)
"""
try_names = set((plugin_name, plugin_name.replace('_', '-')))
return any(fnmatch.fnmatch(name, pattern) for name in try_names)
def register_command(command_class):
# :api
"""A class decorator for automatic command registration."""
def __init__(self, base, cli):
if cli:
cli.register_command(command_class)
plugin_class = type(str(command_class.__name__ + 'Plugin'),
(dnf.Plugin,),
{"__init__": __init__,
"name": command_class.aliases[0]})
command_class._plugin = plugin_class
return command_class
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