JezK
Edit File: 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