Source code for girder.utility.plugin_utilities

#!/usr/bin/env python
# -*- coding: utf-8 -*-

###############################################################################
#  Copyright Kitware Inc.
#
#  Licensed under the Apache License, Version 2.0 ( the "License" );
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
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###############################################################################

"""
The purpose of this module is to provide utility functions related to loading
and registering plugins into the system. The "loadPlugins" and "loadPlugin"
functions are used by the core system to actually load the plugins and create
the pseudo-packages required for easily referencing them. The other functions
in this class are general utility functions designed to be used within the
plugins themselves to help them register with the application.
"""

import codecs
import functools
import girder
import imp
import json
import os
import six
import sys
import yaml
import importlib
import traceback

import pkg_resources
from pkg_resources import iter_entry_points

from girder import logprint, logger
from girder.constants import GIRDER_ROUTE_ID, GIRDER_STATIC_ROUTE_ID, PACKAGE_DIR, ROOT_DIR, \
    ROOT_PLUGINS_PACKAGE, SettingKey
from girder.exceptions import ValidationException
from girder.models.setting import Setting
from girder.utility import mail_utils

_pluginWebroots = {}
_pluginFailureInfo = {}


def _recordPluginFailureInfo(plugin, traceback):
    """
    Record information when a plugin fails to load.

    :param plugin: The name of the plugin that failed to load.
    :type plugin: str
    :param traceback: The traceback of the failure.
    :type trackback: str
    """
    _pluginFailureInfo[plugin] = {
        'traceback': traceback
    }


def _clearPluginFailureInfo(plugin):
    """
    If a plugin loaded, clear any failure information that may have been set by
    an earlier failed attempt.

    :param plugin: The name of the plugin that loaded.
    :type plugin: str
    """
    _pluginFailureInfo.pop(plugin, None)


[docs]def loadPlugins(plugins, root, appconf, apiRoot=None, buildDag=True): """ Loads a set of plugins into the application. :param plugins: The set of plugins to load, by directory name. :type plugins: list :param root: The root node of the server tree. :type root: object :param appconf: The server's cherrypy configuration object. :type appconf: dict :param apiRoot: The cherrypy api root object. :type apiRoot: object or None :param buildDag: If the ``plugins`` parameter is already a topo-sorted list with all dependencies resolved, set this to False and it will skip rebuilding the DAG. Otherwise the dependency resolution and sorting will occur within this method. :type buildDag: bool :returns: A 3-tuple containing the modified root, config, and apiRoot objects. :rtype tuple: """ # Register a pseudo-package for the root of all plugins. This must be # present in the system module list in order to avoid import warnings. if ROOT_PLUGINS_PACKAGE not in sys.modules: module = imp.new_module(ROOT_PLUGINS_PACKAGE) girder.plugins = module sys.modules[ROOT_PLUGINS_PACKAGE] = module logprint.info('Resolving plugin dependencies...') if buildDag: plugins = getToposortedPlugins(plugins, ignoreMissing=True) for plugin in plugins: try: root, appconf, apiRoot = loadPlugin(plugin, root, appconf, apiRoot) _clearPluginFailureInfo(plugin=plugin) logprint.success('Loaded plugin "%s"' % plugin) except Exception: _recordPluginFailureInfo(plugin=plugin, traceback=traceback.format_exc()) logprint.exception('ERROR: Failed to load plugin "%s":' % plugin) return root, appconf, apiRoot
[docs]def getToposortedPlugins(plugins=None, ignoreMissing=False, keys=('dependencies',)): """ Given a set of plugins to load, construct the full DAG of required plugins to load and yields them in toposorted order. :param plugins: A set of plugins that must be in the output list. If you want to toposort all available plugins, omit this parameter. :type plugins: iterable of str :param ignoreMissing: Normally if one of the plugins specified does not exist, this raises a ValidationError. Set this to False to suppress that and instead print an error message and continue. :type ignoreMissing: bool :param keys: Keys that should be used to determine dependencies. :type keys: list of str """ allPlugins = findAllPlugins() dag = {} visited = set() if plugins is None: plugins = set(allPlugins.keys()) else: plugins = set(plugins) def addDeps(plugin): if plugin not in allPlugins: message = 'Required plugin %s does not exist.' % plugin if ignoreMissing: logprint.error(message) return else: raise ValidationException(message) deps = set() for key in keys: deps |= allPlugins[plugin][key] dag[plugin] = deps for dep in deps: if dep in visited: continue visited.add(dep) if dep not in plugins: logger.info('Adding plugin %s because %s requires it' % (dep, plugin)) addDeps(dep) for plugin in plugins: addDeps(plugin) for pset in toposort(dag): for plugin in pset: yield plugin
[docs]def loadPlugin(name, root, appconf, apiRoot=None): """ Loads a plugin into the application. This means allowing it to create endpoints within its own web API namespace, and to register its event listeners, and do anything else it might want to do. :param name: The name of the plugin (i.e. its directory name) :type name: str :param root: The root node of the web API. :param appconf: The cherrypy configuration for the server. :type appconf: dict """ if apiRoot is None: apiRoot = root.api.v1 pluginDir = os.path.join(getPluginDir(), name) isPluginDir = os.path.isdir(os.path.join(pluginDir, 'server')) isPluginFile = os.path.isfile(os.path.join(pluginDir, 'server.py')) pluginLoadMethod = None if not os.path.exists(pluginDir): # Try to load the plugin as an entry_point for entry_point in iter_entry_points(group='girder.plugin', name=name): pluginLoadMethod = entry_point.load() module = importlib.import_module(entry_point.module_name) pluginDir = os.path.dirname(module.__file__) module.PLUGIN_ROOT_DIR = pluginDir girder.plugins.__dict__[name] = module isPluginDir = True if not os.path.exists(pluginDir): raise Exception('Plugin directory does not exist: %s' % pluginDir) if not isPluginDir and not isPluginFile: # This plugin does not have any server-side python code. return root, appconf, apiRoot mailTemplatesDir = os.path.join(pluginDir, 'server', 'mail_templates') if os.path.isdir(mailTemplatesDir): # If the plugin has mail templates, add them to the lookup path mail_utils.addTemplateDirectory(mailTemplatesDir, prepend=True) moduleName = '.'.join((ROOT_PLUGINS_PACKAGE, name)) fp = None try: # @todo this query is run for every plugin that's loaded routeTable = Setting().get(SettingKey.ROUTE_TABLE) info = { 'name': name, 'config': appconf, 'serverRoot': root, 'serverRootPath': routeTable[GIRDER_ROUTE_ID], 'apiRoot': apiRoot, 'staticRoot': routeTable[GIRDER_STATIC_ROUTE_ID], 'pluginRootDir': os.path.abspath(pluginDir) } if pluginLoadMethod is None: fp, pathname, description = imp.find_module('server', [pluginDir]) module = imp.load_module(moduleName, fp, pathname, description) module.PLUGIN_ROOT_DIR = pluginDir girder.plugins.__dict__[name] = module pluginLoadMethod = getattr(module, 'load', None) if pluginLoadMethod is not None: sys.modules[moduleName] = module pluginLoadMethod(info) root, appconf, apiRoot = (info['serverRoot'], info['config'], info['apiRoot']) finally: if fp: fp.close() return root, appconf, apiRoot
[docs]def getPluginDir(): """ Return the path to the directory that plugins are installed. """ # Check if there is a plugins dir next to the girder dir. # This is the case when running from the git repository. pluginsDir = os.path.join(ROOT_DIR, 'plugins') if os.path.isdir(pluginsDir): return pluginsDir # Otherwise, we assume we are in a pip-installed environment where plugins is a subdir. else: return os.path.join(PACKAGE_DIR, 'plugins')
def findEntryPointPlugins(allPlugins): # look for plugins enabled via setuptools `entry_points` for entry_point in iter_entry_points(group='girder.plugin'): # set defaults allPlugins[entry_point.name] = { 'name': entry_point.name, 'description': '', 'version': '', 'dependencies': set() } configJson = os.path.join('girder', 'plugin.json') configYml = os.path.join('girder', 'plugin.yml') data = {} try: if pkg_resources.resource_exists(entry_point.name, configJson): with pkg_resources.resource_stream( entry_point.name, configJson) as conf: try: data = json.load(codecs.getreader('utf8')(conf)) except ValueError: _recordPluginFailureInfo( plugin=entry_point.name, traceback=traceback.format_exc()) logprint.exception( 'ERROR: Plugin "%s": plugin.json is not valid ' 'JSON.' % entry_point.name) elif pkg_resources.resource_exists(entry_point.name, configYml): with pkg_resources.resource_stream( entry_point.name, configYml) as conf: try: data = yaml.safe_load(conf) except yaml.YAMLError: _recordPluginFailureInfo( plugin=entry_point.name, traceback=traceback.format_exc()) logprint.exception( 'ERROR: Plugin "%s": plugin.yml is not valid ' 'YAML.' % entry_point.name) except (ImportError, SystemError): # Fall through and just try to load the entry point below. If # there is still an error, we'll log it there. pass if data == {}: try: data = getattr(entry_point.load(), 'config', {}) except (ImportError, SystemError): # If the plugin failed to load via entrypoint, but is in the # plugins directory, it may still load. We mark and report the # failure; if it loads later, the failure will be cleared, but # the report is still desired. _recordPluginFailureInfo( plugin=entry_point.name, traceback=traceback.format_exc()) logprint.exception( 'ERROR: Plugin "%s": could not be loaded by entrypoint.' % entry_point.name) continue allPlugins[entry_point.name].update(data) allPlugins[entry_point.name]['dependencies'] = set( allPlugins[entry_point.name]['dependencies'])
[docs]def findAllPlugins(): """ Walks the plugin directory to find all of the plugins. If the plugin has a plugin.json/yml file, this reads that file to determine dependencies. """ allPlugins = {} findEntryPointPlugins(allPlugins) pluginDir = getPluginDir() for plugin in os.listdir(pluginDir): path = os.path.join(pluginDir, plugin) if not os.path.isdir(path): # this also allows for symlinked directories continue data = {} configJson = os.path.join(path, 'plugin.json') configYml = os.path.join(path, 'plugin.yml') if os.path.isfile(configJson): with open(configJson) as conf: try: data = json.load(conf) except ValueError: _recordPluginFailureInfo(plugin=plugin, traceback=traceback.format_exc()) logprint.exception( 'ERROR: Plugin "%s": plugin.json is not valid ' 'JSON.' % plugin) elif os.path.isfile(configYml): with open(configYml) as conf: try: data = yaml.safe_load(conf) except yaml.YAMLError: _recordPluginFailureInfo(plugin=plugin, traceback=traceback.format_exc()) logprint.exception( 'ERROR: Plugin "%s": plugin.yml is not valid ' 'YAML.' % plugin) allPlugins[plugin] = { 'name': data.get('name', plugin), 'description': data.get('description', ''), 'url': data.get('url', ''), 'version': data.get('version', ''), 'dependencies': set(data.get('dependencies', [])), 'staticWebDependencies': set(data.get('staticWebDependencies', [])) } return allPlugins
[docs]def toposort(data): """ General-purpose topological sort function. Dependencies are expressed as a dictionary whose keys are items and whose values are a set of dependent items. Output is a list of sets in topological order. This is a generator function that returns a sequence of sets in topological order. :param data: The dependency information. :type data: dict :returns: Yields a list of sorted sets representing the sorted order. """ if not data: return # Ignore self dependencies. for k, v in six.viewitems(data): v.discard(k) # Find all items that don't depend on anything. extra = functools.reduce( set.union, six.viewvalues(data)) - set(six.viewkeys(data)) # Add empty dependencies where needed data.update({item: set() for item in extra}) # Perform the topological sort. while True: ordered = set(item for item, dep in six.viewitems(data) if not dep) if not ordered: break yield ordered data = {item: (dep - ordered) for item, dep in six.viewitems(data) if item not in ordered} # Detect any cycles in the dependency graph. if data: raise Exception('Cyclic dependencies detected:\n%s' % '\n'.join( repr(x) for x in six.viewitems(data)))
[docs]def addChildNode(node, name, obj=None): """ Use this to build paths to your plugin's endpoints. :param node: The parent node to add the child node to. :param name: The name of the child node in the URL path. :type name: str :param obj: The object to place at this new node, or None if this child should not be exposed as an endpoint, instead just used as an intermediary hidden node. :type obj: object or None :returns: The node that was created. """ if obj: setattr(node, name, obj) return obj else: hiddenNode = type('', (), dict(exposed=False))() setattr(node, name, hiddenNode) return hiddenNode
def getPluginWebroots(): global _pluginWebroots return _pluginWebroots
[docs]def registerPluginWebroot(webroot, name): """ Adds a webroot to the global registry for plugins based on the plugin name. """ global _pluginWebroots _pluginWebroots[name] = webroot
def getPluginFailureInfo(): return _pluginFailureInfo
[docs]class config(object): # noqa: class name """ Wrap a plugin's ``load`` method appending plugin metadata. :param name str: The plugin's name :param description str: A brief description of the plugin. :param version str: A semver compatible version string. :param dependencies list: A list of plugins required by this plugin. :param python3 bool: Whether this plugin supports python3. :returns: A decorator that appends the metadata to the method """ def __init__(self, **kw): self.config = kw def __call__(self, func): @six.wraps(func) def wrapped(*arg, **kw): return func(*arg, **kw) wrapped.config = self.config return wrapped