Edit File: disco.py
"""Utilities for plugins discovery and selection.""" import itertools import logging import sys from typing import Callable from typing import cast from typing import Dict from typing import Iterable from typing import Iterator from typing import List from typing import Mapping from typing import Optional from typing import Type from typing import Union import warnings import pkg_resources import zope.interface import zope.interface.verify from certbot import configuration from certbot import errors from certbot import interfaces from certbot._internal import constants from certbot.compat import os from certbot.errors import Error logger = logging.getLogger(__name__) PREFIX_FREE_DISTRIBUTIONS = [ "certbot", "certbot-apache", "certbot-dns-cloudflare", "certbot-dns-cloudxns", "certbot-dns-digitalocean", "certbot-dns-dnsimple", "certbot-dns-dnsmadeeasy", "certbot-dns-gehirn", "certbot-dns-google", "certbot-dns-linode", "certbot-dns-luadns", "certbot-dns-nsone", "certbot-dns-ovh", "certbot-dns-rfc2136", "certbot-dns-route53", "certbot-dns-sakuracloud", "certbot-nginx", ] """Distributions for which prefix will be omitted.""" class PluginEntryPoint: """Plugin entry point.""" # this object is mutable, don't allow it to be hashed! __hash__ = None # type: ignore def __init__(self, entry_point: pkg_resources.EntryPoint, with_prefix: bool = False) -> None: self.name = self.entry_point_to_plugin_name(entry_point, with_prefix) self.plugin_cls: Type[interfaces.Plugin] = entry_point.load() self.entry_point = entry_point self.warning_message: Optional[str] = None self._initialized: Optional[interfaces.Plugin] = None self._prepared: Optional[Union[bool, Error]] = None self._hidden = False self._long_description: Optional[str] = None def check_name(self, name: Optional[str]) -> bool: """Check if the name refers to this plugin.""" if name == self.name: if self.warning_message: logger.warning(self.warning_message) return True return False @classmethod def entry_point_to_plugin_name(cls, entry_point: pkg_resources.EntryPoint, with_prefix: bool) -> str: """Unique plugin name for an ``entry_point``""" if with_prefix: if not entry_point.dist: raise errors.Error(f"Entrypoint {entry_point.name} has no distribution!") return entry_point.dist.key + ":" + entry_point.name return entry_point.name @property def description(self) -> str: """Description of the plugin.""" return self.plugin_cls.description @property def description_with_name(self) -> str: """Description with name. Handy for UI.""" return "{0} ({1})".format(self.description, self.name) @property def long_description(self) -> str: """Long description of the plugin.""" if self._long_description: return self._long_description return getattr(self.plugin_cls, "long_description", self.description) @long_description.setter def long_description(self, description: str) -> None: self._long_description = description @property def hidden(self) -> bool: """Should this plugin be hidden from UI?""" return self._hidden or getattr(self.plugin_cls, "hidden", False) @hidden.setter def hidden(self, hide: bool) -> None: self._hidden = hide def ifaces(self, *ifaces_groups: Iterable[Type]) -> bool: """Does plugin implements specified interface groups?""" return not ifaces_groups or any( all(_implements(self.plugin_cls, iface) for iface in ifaces) for ifaces in ifaces_groups) @property def initialized(self) -> bool: """Has the plugin been initialized already?""" return self._initialized is not None def init(self, config: Optional[configuration.NamespaceConfig] = None) -> interfaces.Plugin: """Memoized plugin initialization.""" if not self._initialized: self.entry_point.require() # fetch extras! # For plugins implementing ABCs Plugin, Authenticator or Installer, the following # line will raise an exception if some implementations of abstract methods are missing. self._initialized = self.plugin_cls(config, self.name) return self._initialized def verify(self, ifaces: Iterable[Type]) -> bool: """Verify that the plugin conforms to the specified interfaces.""" if not self.initialized: raise ValueError("Plugin is not initialized.") for iface in ifaces: # zope.interface.providedBy(plugin) if not _verify(self.init(), self.plugin_cls, iface): return False return True @property def prepared(self) -> bool: """Has the plugin been prepared already?""" if not self.initialized: logger.debug(".prepared called on uninitialized %r", self) return self._prepared is not None def prepare(self) -> Union[bool, Error]: """Memoized plugin preparation.""" if self._initialized is None: raise ValueError("Plugin is not initialized.") if self._prepared is None: try: self._initialized.prepare() except errors.MisconfigurationError as error: logger.debug("Misconfigured %r: %s", self, error, exc_info=True) self._prepared = error except errors.NoInstallationError as error: logger.debug( "No installation (%r): %s", self, error, exc_info=True) self._prepared = error except errors.PluginError as error: logger.debug("Other error:(%r): %s", self, error, exc_info=True) self._prepared = error else: self._prepared = True # Mypy seems to fail to understand the actual type here, let's help it. return cast(Union[bool, Error], self._prepared) @property def misconfigured(self) -> bool: """Is plugin misconfigured?""" return isinstance(self._prepared, errors.MisconfigurationError) @property def problem(self) -> Optional[Exception]: """Return the Exception raised during plugin setup, or None if all is well""" if isinstance(self._prepared, Exception): return self._prepared return None @property def available(self) -> bool: """Is plugin available, i.e. prepared or misconfigured?""" return self._prepared is True or self.misconfigured def __repr__(self) -> str: return "PluginEntryPoint#{0}".format(self.name) def __str__(self) -> str: lines = [ "* {0}".format(self.name), "Description: {0}".format(self.plugin_cls.description), "Interfaces: {0}".format(", ".join( cls.__name__ for cls in self.plugin_cls.mro() if cls.__module__ == 'certbot.interfaces' )), "Entry point: {0}".format(self.entry_point), ] if self.initialized: lines.append("Initialized: {0}".format(self.init())) if self.prepared: lines.append("Prep: {0}".format(self.prepare())) return "\n".join(lines) class PluginsRegistry(Mapping): """Plugins registry.""" def __init__(self, plugins: Mapping[str, PluginEntryPoint]) -> None: # plugins are sorted so the same order is used between runs. # This prevents deadlock caused by plugins acquiring a lock # and ensures at least one concurrent Certbot instance will run # successfully. self._plugins = dict(sorted(plugins.items())) @classmethod def find_all(cls) -> 'PluginsRegistry': """Find plugins using setuptools entry points.""" plugins: Dict[str, PluginEntryPoint] = {} plugin_paths_string = os.getenv('CERTBOT_PLUGIN_PATH') plugin_paths = plugin_paths_string.split(':') if plugin_paths_string else [] # XXX should ensure this only happens once sys.path.extend(plugin_paths) for plugin_path in plugin_paths: pkg_resources.working_set.add_entry(plugin_path) entry_points = itertools.chain( pkg_resources.iter_entry_points( constants.SETUPTOOLS_PLUGINS_ENTRY_POINT), pkg_resources.iter_entry_points( constants.OLD_SETUPTOOLS_PLUGINS_ENTRY_POINT),) for entry_point in entry_points: plugin_ep = cls._load_entry_point(entry_point, plugins, with_prefix=False) # entry_point.dist cannot be None here, we would have blown up # earlier, however, this assertion is needed for mypy. assert entry_point.dist is not None if entry_point.dist.key not in PREFIX_FREE_DISTRIBUTIONS: prefixed_plugin_ep = cls._load_entry_point(entry_point, plugins, with_prefix=True) prefixed_plugin_ep.hidden = True message = ( "Plugin legacy name {0} may be removed in a future version. " "Please use {1} instead.").format(prefixed_plugin_ep.name, plugin_ep.name) prefixed_plugin_ep.warning_message = message prefixed_plugin_ep.long_description = "(WARNING: {0}) {1}".format( message, prefixed_plugin_ep.long_description) return cls(plugins) @classmethod def _load_entry_point(cls, entry_point: pkg_resources.EntryPoint, plugins: Dict[str, PluginEntryPoint], with_prefix: bool) -> PluginEntryPoint: plugin_ep = PluginEntryPoint(entry_point, with_prefix) if plugin_ep.name in plugins: other_ep = plugins[plugin_ep.name] plugin1 = plugin_ep.entry_point.dist.key if plugin_ep.entry_point.dist else "unknown" plugin2 = other_ep.entry_point.dist.key if other_ep.entry_point.dist else "unknown" raise Exception("Duplicate plugin name {0} from {1} and {2}.".format( plugin_ep.name, plugin1, plugin2)) if _provides(plugin_ep.plugin_cls, interfaces.Plugin): plugins[plugin_ep.name] = plugin_ep else: # pragma: no cover logger.warning( "%r does not inherit from Plugin, skipping", plugin_ep) return plugin_ep def __getitem__(self, name: str) -> PluginEntryPoint: return self._plugins[name] def __iter__(self) -> Iterator[str]: return iter(self._plugins) def __len__(self) -> int: return len(self._plugins) def init(self, config: configuration.NamespaceConfig) -> List[interfaces.Plugin]: """Initialize all plugins in the registry.""" return [plugin_ep.init(config) for plugin_ep in self._plugins.values()] def filter(self, pred: Callable[[PluginEntryPoint], bool]) -> "PluginsRegistry": """Filter plugins based on predicate.""" return type(self)({name: plugin_ep for name, plugin_ep in self._plugins.items() if pred(plugin_ep)}) def visible(self) -> "PluginsRegistry": """Filter plugins based on visibility.""" return self.filter(lambda plugin_ep: not plugin_ep.hidden) def ifaces(self, *ifaces_groups: Iterable[Type]) -> "PluginsRegistry": """Filter plugins based on interfaces.""" return self.filter(lambda p_ep: p_ep.ifaces(*ifaces_groups)) def verify(self, ifaces: Iterable[Type]) -> "PluginsRegistry": """Filter plugins based on verification.""" return self.filter(lambda p_ep: p_ep.verify(ifaces)) def prepare(self) -> List[Union[bool, Error]]: """Prepare all plugins in the registry.""" return [plugin_ep.prepare() for plugin_ep in self._plugins.values()] def available(self) -> "PluginsRegistry": """Filter plugins based on availability.""" return self.filter(lambda p_ep: p_ep.available) # successfully prepared + misconfigured def find_init(self, plugin: interfaces.Plugin) -> Optional[PluginEntryPoint]: """Find an initialized plugin. This is particularly useful for finding a name for the plugin:: # plugin is an instance providing Plugin, initialized # somewhere else in the code plugin_registry.find_init(plugin).name Returns ``None`` if ``plugin`` is not found in the registry. """ # use list instead of set because PluginEntryPoint is not hashable candidates = [plugin_ep for plugin_ep in self._plugins.values() if plugin_ep.initialized and plugin_ep.init() is plugin] assert len(candidates) <= 1 if candidates: return candidates[0] return None def __repr__(self) -> str: return "{0}({1})".format( self.__class__.__name__, ','.join( repr(p_ep) for p_ep in self._plugins.values())) def __str__(self) -> str: if not self._plugins: return "No plugins" return "\n\n".join(str(p_ep) for p_ep in self._plugins.values()) _DEPRECATION_PLUGIN = ("Zope interface certbot.interfaces.IPlugin is deprecated, " "use ABC certbot.interface.Plugin instead.") _DEPRECATION_AUTHENTICATOR = ("Zope interface certbot.interfaces.IAuthenticator is deprecated, " "use ABC certbot.interface.Authenticator instead.") _DEPRECATION_INSTALLER = ("Zope interface certbot.interfaces.IInstaller is deprecated, " "use ABC certbot.interface.Installer instead.") _DEPRECATION_FACTORY = ("Zope interface certbot.interfaces.IPluginFactory is deprecated, " "use ABC certbot.interface.Plugin instead.") def _provides(target_class: Type[interfaces.Plugin], iface: Type) -> bool: if issubclass(target_class, iface): return True if iface == interfaces.Plugin and interfaces.IPluginFactory.providedBy(target_class): logging.warning(_DEPRECATION_FACTORY) warnings.warn(_DEPRECATION_FACTORY, DeprecationWarning) return True return False def _implements(target_class: Type[interfaces.Plugin], iface: Type) -> bool: if issubclass(target_class, iface): return True if iface == interfaces.Plugin and interfaces.IPlugin.implementedBy(target_class): logging.warning(_DEPRECATION_PLUGIN) warnings.warn(_DEPRECATION_PLUGIN, DeprecationWarning) return True if iface == interfaces.Authenticator and interfaces.IAuthenticator.implementedBy(target_class): logging.warning(_DEPRECATION_AUTHENTICATOR) warnings.warn(_DEPRECATION_AUTHENTICATOR, DeprecationWarning) return True if iface == interfaces.Installer and interfaces.IInstaller.implementedBy(target_class): logging.warning(_DEPRECATION_INSTALLER) warnings.warn(_DEPRECATION_INSTALLER, DeprecationWarning) return True return False def _verify(target_instance: interfaces.Plugin, target_class: Type[interfaces.Plugin], iface: Type) -> bool: if issubclass(target_class, iface): # No need to trigger some verify logic for ABCs: when the object is instantiated, # an error would be raised if implementation is not done properly. # So the checks have been done effectively when the plugin has been initialized. return True zope_iface: Optional[Type[zope.interface.Interface]] = None message = "" if iface == interfaces.Plugin: zope_iface = interfaces.IPlugin message = _DEPRECATION_PLUGIN if iface == interfaces.Authenticator: zope_iface = interfaces.IAuthenticator message = _DEPRECATION_AUTHENTICATOR if iface == interfaces.Installer: zope_iface = interfaces.IInstaller message = _DEPRECATION_INSTALLER if not zope_iface: raise ValueError(f"Unexpected type: {iface.__name__}") try: zope.interface.verify.verifyObject(zope_iface, target_instance) logging.warning(message) warnings.warn(message, DeprecationWarning) return True except zope.interface.exceptions.BrokenImplementation as error: if zope_iface.implementedBy(target_class): logger.debug( "%s implements %s but object does not verify: %s", target_class, zope_iface.__name__, error, exc_info=True) return False
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