Source code for Bcfg2.Server.Core

""" Bcfg2.Server.Core provides the base core object that server core
implementations inherit from. """

import os
import pwd
import atexit
import logging
import select
import sys
import threading
import time
import inspect
import lxml.etree
import daemon
import Bcfg2.settings
import Bcfg2.Server
import Bcfg2.Logger
import Bcfg2.Server.FileMonitor
from Bcfg2.Cache import Cache
import Bcfg2.Statistics
from itertools import chain
from Bcfg2.Compat import xmlrpclib, wraps  # pylint: disable=W0622
from Bcfg2.Server.Plugin.exceptions import *  # pylint: disable=W0401,W0614
from Bcfg2.Server.Plugin.interfaces import *  # pylint: disable=W0401,W0614
from Bcfg2.Server.Plugin import track_statistics

    import psyco
except ImportError:

os.environ['DJANGO_SETTINGS_MODULE'] = 'Bcfg2.settings'

[docs]def exposed(func): """ Decorator that sets the ``exposed`` attribute of a function to ``True`` expose it via XML-RPC. This currently works for both the builtin and CherryPy cores, although if other cores are added this may need to be made a core-specific function. :param func: The function to decorate :type func: callable :returns: callable - the decorated function""" = True return func
[docs]def sort_xml(node, key=None): """ Recursively sort an XML document in a deterministic fashion. This shouldn't be used to perform a *useful* sort, merely to put XML in a deterministic, replicable order. The document is sorted in-place. :param node: The root node of the XML tree to sort :type node: lxml.etree._Element or lxml.etree.ElementTree :param key: The key to sort by :type key: callable :returns: None """ for child in node: sort_xml(child, key) try: sorted_children = sorted(node, key=key) except TypeError: sorted_children = node node[:] = sorted_children
[docs]def close_db_connection(func): """ Decorator that closes the Django database connection at the end of the function. This should decorate any exposed function that might open a database connection. """ @wraps(func) def inner(self, *args, **kwargs): """ The decorated function """ rv = func(self, *args, **kwargs) if self._database_available: # pylint: disable=W0212 from django import db self.logger.debug("%s: Closing database connection" % threading.current_thread().getName()) db.close_connection() return rv return inner
[docs]class CoreInitError(Exception): """ Raised when the server core cannot be initialized. """ pass
[docs]class NoExposedMethod (Exception): """ Raised when an XML-RPC method is called, but there is no method exposed with the given name. """ # pylint: disable=W0702 # in core we frequently want to catch all exceptions, regardless of # type, so disable the pylint rule that catches that.
[docs]class BaseCore(object): """ The server core is the container for all Bcfg2 server logic and modules. All core implementations must inherit from ``BaseCore``. """ name = "core" def __init__(self, setup): # pylint: disable=R0912,R0915 """ :param setup: A Bcfg2 options dict :type setup: Bcfg2.Options.OptionParser .. automethod:: _daemonize .. automethod:: _drop_privileges .. automethod:: _run .. automethod:: _block .. ----- .. automethod:: _file_monitor_thread .. automethod:: _perflog_thread """ #: The Bcfg2 repository directory self.datastore = setup['repo'] if setup['verbose']: level = logging.INFO else: level = logging.WARNING # we set a higher log level for the console by default. we # assume that if someone is running bcfg2-server in such a way # that it _can_ log to console, they want more output. if # level is set to DEBUG, that will get handled by # setup_logging and the console will get DEBUG output. Bcfg2.Logger.setup_logging('bcfg2-server', to_console=logging.INFO, to_syslog=setup['syslog'], to_file=setup['logging'], level=level) #: A :class:`logging.Logger` object for use by the core self.logger = logging.getLogger('bcfg2-server') #: Log levels for the various logging handlers with debug True #: and False. Each loglevel dict is a dict of ``logger name #: => log level``; the logger names are set in #: :mod:`Bcfg2.Logger`. The logger name ``default`` is #: special, and will be used for any log handlers whose name #: does not appear elsewhere in the dict. At a minimum, #: ``default`` must be provided. self._loglevels = {True: dict(default=logging.DEBUG), False: dict(console=logging.INFO, default=level)} #: Used to keep track of the current debug state of the core. self.debug_flag = False # enable debugging on the core now. debugging is enabled on # everything else later if setup['debug']: self.set_core_debug(None, setup['debug']) try: filemonitor = \ Bcfg2.Server.FileMonitor.available[setup['filemonitor']] except KeyError: self.logger.error("File monitor driver %s not available; " "forcing to default" % setup['filemonitor']) filemonitor = Bcfg2.Server.FileMonitor.available['default'] famargs = dict(ignore=[], debug=False) if 'ignore' in setup: famargs['ignore'] = setup['ignore'] if 'debug' in setup: famargs['debug'] = setup['debug'] try: #: The :class:`Bcfg2.Server.FileMonitor.FileMonitor` #: object used by the core to monitor for Bcfg2 data #: changes. self.fam = filemonitor(**famargs) except IOError: msg = "Failed to instantiate fam driver %s" % setup['filemonitor'] self.logger.error(msg, exc_info=1) raise CoreInitError(msg) #: Path to bcfg2.conf self.cfile = setup['configfile'] #: Dict of plugins that are enabled. Keys are the plugin #: names (just the plugin name, in the correct case; e.g., #: "Cfg", not "Bcfg2.Server.Plugins.Cfg"), and values are #: plugin objects. self.plugins = {} #: Blacklist of plugins that conflict with enabled plugins. #: If two plugins are loaded that conflict with each other, #: the first one loaded wins. self.plugin_blacklist = {} #: The Metadata plugin self.metadata = None #: Revision of the Bcfg2 specification. This will be sent to #: the client in the configuration, and can be set by a #: :class:`Bcfg2.Server.Plugin.interfaces.Version` plugin. self.revision = '-1' #: The Bcfg2 options dict self.setup = setup atexit.register(self.shutdown) #: if :func:`Bcfg2.Server.Core.shutdown` is called explicitly, #: then :mod:`atexit` calls it *again*, so it gets called #: twice. This is potentially bad, so we use #: :attr:`Bcfg2.Server.Core._running` as a flag to determine #: if the core needs to be shutdown, and only do it once. self._running = True #: Threading event to signal worker threads (e.g., #: :attr:`fam_thread`) to shutdown self.terminate = threading.Event() #: RLock to be held on writes to the backend db self.db_write_lock = threading.RLock() # generate Django ORM settings. this must be done _before_ we # load plugins Bcfg2.settings.read_config(repo=self.datastore) # mapping of group name => plugin name to record where groups # that are created by Connector plugins came from self._dynamic_groups = dict() #: Whether or not it's possible to use the Django database #: backend for plugins that have that capability self._database_available = False if Bcfg2.settings.HAS_DJANGO: db_settings = Bcfg2.settings.DATABASES['default'] if ('daemon' in self.setup and 'daemon_uid' in self.setup and self.setup['daemon'] and self.setup['daemon_uid'] and db_settings['ENGINE'].endswith(".sqlite3") and not os.path.exists(db_settings['NAME'])): # syncdb will create the sqlite database, and we're # going to daemonize, dropping privs to a non-root # user, so we need to chown the database after # creating it do_chown = True else: do_chown = False from django.core.exceptions import ImproperlyConfigured from django.core import management try: management.call_command("syncdb", interactive=False, verbosity=0) self._database_available = True except ImproperlyConfigured: self.logger.error("Django configuration problem: %s" % sys.exc_info()[1]) except: self.logger.error("Database update failed: %s" % sys.exc_info()[1]) if do_chown and self._database_available: try: os.chown(db_settings['NAME'], self.setup['daemon_uid'], self.setup['daemon_gid']) except OSError: err = sys.exc_info()[1] self.logger.error("Failed to set ownership of database " "at %s: %s" % (db_settings['NAME'], err)) #: The CA that signed the server cert = setup['ca'] #: The FAM :class:`threading.Thread`, #: :func:`_file_monitor_thread` self.fam_thread = \ threading.Thread(name="%sFAMThread" % setup['filemonitor'], target=self._file_monitor_thread) self.perflog_thread = None if self.setup['perflog']: self.perflog_thread = \ threading.Thread(name="PerformanceLoggingThread", target=self._perflog_thread) #: A :func:`threading.Lock` for use by #: :func:`Bcfg2.Server.FileMonitor.FileMonitor.handle_event_set` self.lock = threading.Lock() #: A :class:`Bcfg2.Cache.Cache` object for caching client #: metadata self.metadata_cache = Cache()
[docs] def expire_caches_by_type(self, base_cls, key=None): """ Expire caches for all :class:`Bcfg2.Server.Plugin.interfaces.Caching` plugins that are instances of ``base_cls``. :param base_cls: The base plugin interface class to match (see :mod:`Bcfg2.Server.Plugin.interfaces`) :type base_cls: type :param key: The cache key to expire """ for plugin in self.plugins_by_type(base_cls): if isinstance(plugin, Bcfg2.Server.Plugin.Caching): plugin.expire_cache(key)
[docs] def plugins_by_type(self, base_cls): """ Return a list of loaded plugins that match the passed type. The returned list is sorted in ascending order by the plugins' ``sort_order`` value. The :attr:`Bcfg2.Server.Plugin.base.Plugin.sort_order` defaults to 500, but can be overridden by individual plugins. Plugins with the same numerical sort_order value are sorted in alphabetical order by their name. :param base_cls: The base plugin interface class to match (see :mod:`Bcfg2.Server.Plugin.interfaces`) :type base_cls: type :returns: list of :attr:`Bcfg2.Server.Plugin.base.Plugin` objects """ return sorted([plugin for plugin in self.plugins.values() if isinstance(plugin, base_cls)], key=lambda p: (p.sort_order,
[docs] def _perflog_thread(self): """ The thread that periodically logs performance statistics to syslog. """ self.logger.debug("Performance logging thread starting") while not self.terminate.isSet(): self.terminate.wait(self.setup['perflog_interval']) if not self.terminate.isSet(): for name, stats in self.get_statistics(None).items():"Performance statistics: " "%s min=%.06f, max=%.06f, average=%.06f, " "count=%d" % ((name, ) + stats))"Performance logging thread terminated")
[docs] def _file_monitor_thread(self): """ The thread that runs the :class:`Bcfg2.Server.FileMonitor.FileMonitor`. This also queries :class:`Bcfg2.Server.Plugin.interfaces.Version` plugins for the current revision of the Bcfg2 repo. """ self.logger.debug("File monitor thread starting") famfd = self.fam.fileno() terminate = self.terminate while not terminate.isSet(): try: if famfd:[famfd], [], [], 2) else: if not self.fam.pending(): terminate.wait(15) if self.fam.pending(): self._update_vcs_revision() self.fam.handle_event_set(self.lock) except: continue"File monitor thread terminated")
@track_statistics() def _update_vcs_revision(self): """ Update the revision of the current configuration on-disk from the VCS plugin """ for plugin in self.plugins_by_type(Version): try: newrev = plugin.get_revision() if newrev != self.revision: self.logger.debug("Updated to revision %s" % newrev) self.revision = newrev break except: self.logger.warning("Error getting revision from %s: %s" % (, sys.exc_info()[1])) self.revision = '-1'
[docs] def load_plugins(self): """ Load all plugins, setting :attr:`Bcfg2.Server.Core.BaseCore.plugins` and :attr:`Bcfg2.Server.Core.BaseCore.metadata` as side effects. This does not start plugin threads; that is done later, in :func:`` """ while '' in self.setup['plugins']: self.setup['plugins'].remove('') for plugin in self.setup['plugins']: if plugin not in self.plugins: self.init_plugin(plugin) # Remove blacklisted plugins for plugin, blacklist in list(self.plugin_blacklist.items()): if len(blacklist) > 0: self.logger.error("The following plugins conflict with %s;" "Unloading %s" % (plugin, blacklist)) for plug in blacklist: del self.plugins[plug] # Log experimental plugins expl = [plug for plug in list(self.plugins.values()) if plug.experimental] if expl:"Loading experimental plugin(s): %s" % (" ".join([ for x in expl])))"NOTE: Interfaces subject to change") # Log deprecated plugins depr = [plug for plug in list(self.plugins.values()) if plug.deprecated] if depr:"Loading deprecated plugin(s): %s" % (" ".join([ for x in depr]))) # Find the metadata plugin and set self.metadata mlist = self.plugins_by_type(Metadata) if len(mlist) >= 1: self.metadata = mlist[0] if len(mlist) > 1: self.logger.error("Multiple Metadata plugins loaded; using %s" % self.metadata) else: self.logger.error("No Metadata plugin loaded; " "failed to instantiate Core") raise CoreInitError("No Metadata Plugin") if self.debug_flag: # enable debugging on plugins self.plugins[plugin].set_debug(self.debug_flag)
[docs] def init_plugin(self, plugin): """ Import and instantiate a single plugin. The plugin is stored to :attr:`plugins`. :param plugin: The name of the plugin. This is just the name of the plugin, in the appropriate case. I.e., ``Cfg``, not ``Bcfg2.Server.Plugins.Cfg``. :type plugin: string :returns: None """ self.logger.debug("%s: Loading plugin %s" % (, plugin)) try: mod = getattr(__import__("Bcfg2.Server.Plugins.%s" % (plugin)).Server.Plugins, plugin) except ImportError: try: mod = __import__(plugin, globals(), locals(), [plugin.split('.')[-1]]) except: self.logger.error("Failed to load plugin %s" % plugin) return try: plug = getattr(mod, plugin.split('.')[-1]) except AttributeError: self.logger.error("Failed to load plugin %s: %s" % (plugin, sys.exc_info()[1])) return # Blacklist conflicting plugins cplugs = [conflict for conflict in plug.conflicts if conflict in self.plugins] self.plugin_blacklist[] = cplugs try: self.plugins[plugin] = plug(self, self.datastore) except PluginInitError: self.logger.error("Failed to instantiate plugin %s" % plugin, exc_info=1) except OSError: err = sys.exc_info()[1] self.logger.error("Failed to add a file monitor while " "instantiating plugin %s: %s" % (plugin, err)) except: self.logger.error("Unexpected instantiation failure for plugin %s" % plugin, exc_info=1)
[docs] def shutdown(self): """ Perform plugin and FAM shutdown tasks. """ if not self._running: self.logger.debug("%s: Core already shut down" % return"%s: Shutting down core..." % if not self.terminate.isSet(): self.terminate.set() self._running = False self.fam.shutdown()"%s: FAM shut down" % for plugin in list(self.plugins.values()): plugin.shutdown()"%s: All plugins shut down" % if self._database_available: from django import db"%s: Closing database connection" % db.close_connection()
[docs] def metadata_cache_mode(self): """ Get the client :attr:`metadata_cache` mode. Options are off, initial, cautious, aggressive, on (synonym for cautious). See :ref:`server-caching` for more details. """ mode = self.setup.cfp.get("caching", "client_metadata", default="off").lower() if mode == "on": return "cautious" else: return mode
[docs] def client_run_hook(self, hook, metadata): """ Invoke hooks from :class:`Bcfg2.Server.Plugin.interfaces.ClientRunHooks` plugins for a given stage. :param hook: The name of the stage to run hooks for. A stage can be any abstract function defined in the :class:`Bcfg2.Server.Plugin.interfaces.ClientRunHooks` interface. :type hook: string :param metadata: Client metadata to run the hook for. This will be passed as the sole argument to each hook. :type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata """ self.logger.debug("Running %s hooks for %s" % (hook, metadata.hostname)) start = time.time() try: for plugin in self.plugins_by_type(ClientRunHooks): try: getattr(plugin, hook)(metadata) except AttributeError: err = sys.exc_info()[1] self.logger.error("Unknown attribute: %s" % err) raise except: err = sys.exc_info()[1] self.logger.error("%s: Error invoking hook %s: %s" % (plugin, hook, err)) finally: Bcfg2.Statistics.stats.add_value("%s:client_run_hook:%s" % (self.__class__.__name__, hook), time.time() - start)
[docs] def validate_structures(self, metadata, data): """ Checks the data structures by calling the :func:`Bcfg2.Server.Plugin.interfaces.StructureValidator.validate_structures` method of :class:`Bcfg2.Server.Plugin.interfaces.StructureValidator` plugins. :param metadata: Client metadata to validate structures for :type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata :param data: The list of structures (i.e., bundles) for this client :type data: list of lxml.etree._Element objects """ self.logger.debug("Validating structures for %s" % metadata.hostname) for plugin in self.plugins_by_type(StructureValidator): try: plugin.validate_structures(metadata, data) except ValidationError: err = sys.exc_info()[1] self.logger.error("Plugin %s structure validation failed: %s" % (, err)) raise except: self.logger.error("Plugin %s: unexpected structure validation " "failure" %, exc_info=1)
[docs] def validate_goals(self, metadata, data): """ Checks that the config matches the goals enforced by :class:`Bcfg2.Server.Plugin.interfaces.GoalValidator` plugins by calling :func:`Bcfg2.Server.Plugin.interfaces.GoalValidator.validate_goals`. :param metadata: Client metadata to validate goals for :type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata :param data: The list of structures (i.e., bundles) for this client :type data: list of lxml.etree._Element objects """ self.logger.debug("Validating goals for %s" % metadata.hostname) for plugin in self.plugins_by_type(GoalValidator): try: plugin.validate_goals(metadata, data) except ValidationError: err = sys.exc_info()[1] self.logger.error("Plugin %s goal validation failed: %s" % (, err.message)) raise except: self.logger.error("Plugin %s: unexpected goal validation " "failure" %, exc_info=1)
[docs] def GetStructures(self, metadata): """ Get all structures (i.e., bundles) for the given client :param metadata: Client metadata to get structures for :type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata :returns: list of :class:`lxml.etree._Element` objects """ self.logger.debug("Getting structures for %s" % metadata.hostname) structures = list( chain(*[struct.BuildStructures(metadata) for struct in self.plugins_by_type(Structure)])) sbundles = [b.get('name') for b in structures if b.tag == 'Bundle'] missing = [b for b in metadata.bundles if b not in sbundles] if missing: self.logger.error("Client %s configuration missing bundles: %s" % (metadata.hostname, ':'.join(missing))) return structures
[docs] def BindStructures(self, structures, metadata, config): """ Given a list of structures (i.e. bundles), bind all the entries in them and add the structures to the config. :param structures: The list of structures for this client :type structures: list of lxml.etree._Element objects :param metadata: Client metadata to bind structures for :type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata :param config: The configuration document to add fully-bound structures to. Modified in-place. :type config: lxml.etree._Element """ self.logger.debug("Binding structures for %s" % metadata.hostname) for astruct in structures: try: self.BindStructure(astruct, metadata) config.append(astruct) except: self.logger.error("error in BindStructure", exc_info=1)
[docs] def BindStructure(self, structure, metadata): """ Bind all elements in a single structure (i.e., bundle). :param structure: The structure to bind. Modified in-place. :type structures: lxml.etree._Element :param metadata: Client metadata to bind structure for :type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata """ self.logger.debug("Binding structure %s for %s" % (structure.get("name", "unknown"), metadata.hostname)) for entry in structure.getchildren(): if entry.tag.startswith("Bound"): entry.tag = entry.tag[5:] continue try: self.Bind(entry, metadata) except: exc = sys.exc_info()[1] if 'failure' not in entry.attrib: entry.set('failure', 'bind error: %s' % exc) if isinstance(exc, PluginExecutionError): msg = "Failed to bind entry" else: msg = "Unexpected failure binding entry" self.logger.error("%s %s:%s: %s" % (msg, entry.tag, entry.get('name'), exc))
[docs] def Bind(self, entry, metadata): """ Bind a single entry using the appropriate generator. :param entry: The entry to bind. Modified in-place. :type entry: lxml.etree._Element :param metadata: Client metadata to bind structure for :type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata """ start = time.time() if 'altsrc' in entry.attrib: oldname = entry.get('name') entry.set('name', entry.get('altsrc')) entry.set('realname', oldname) del entry.attrib['altsrc'] try: ret = self.Bind(entry, metadata) entry.set('name', oldname) del entry.attrib['realname'] return ret except: self.logger.error( "Failed binding entry %s:%s with altsrc %s: %s" % (entry.tag, entry.get('realname'), entry.get('name'), sys.exc_info()[1])) entry.set('name', oldname) self.logger.error("Falling back to %s:%s" % (entry.tag, entry.get('name'))) generators = self.plugins_by_type(Generator) glist = [gen for gen in generators if entry.get('name') in gen.Entries.get(entry.tag, {})] if len(glist) == 1: return glist[0].Entries[entry.tag][entry.get('name')](entry, metadata) elif len(glist) > 1: generators = ", ".join([ for gen in glist]) self.logger.error("%s %s served by multiple generators: %s" % (entry.tag, entry.get('name'), generators)) g2list = [gen for gen in generators if gen.HandlesEntry(entry, metadata)] try: if len(g2list) == 1: return g2list[0].HandleEntry(entry, metadata) entry.set('failure', 'no matching generator') raise PluginExecutionError("No matching generator: %s:%s" % (entry.tag, entry.get('name'))) finally: Bcfg2.Statistics.stats.add_value("%s:Bind:%s" % (self.__class__.__name__, entry.tag), time.time() - start)
[docs] def BuildConfiguration(self, client): """ Build the complete configuration for a client. :param client: The hostname of the client to build the configuration for :type client: string :returns: :class:`lxml.etree._Element` - A complete Bcfg2 configuration document """ self.logger.debug("Building configuration for %s" % client) start = time.time() config = lxml.etree.Element("Configuration", version='2.0', revision=self.revision) try: meta = self.build_metadata(client) except MetadataConsistencyError: self.logger.error("Metadata consistency error for client %s" % client) return lxml.etree.Element("error", type='metadata error') self.client_run_hook("start_client_run", meta) try: structures = self.GetStructures(meta) except: self.logger.error("Error in GetStructures", exc_info=1) return lxml.etree.Element("error", type='structure error') self.validate_structures(meta, structures) # Perform altsrc consistency checking esrcs = {} for struct in structures: for entry in struct: key = (entry.tag, entry.get('name')) if key in esrcs: if esrcs[key] != entry.get('altsrc'): self.logger.error("Found inconsistent altsrc mapping " "for entry %s:%s" % key) else: esrcs[key] = entry.get('altsrc', None) del esrcs self.BindStructures(structures, meta, config) self.validate_goals(meta, config) self.client_run_hook("end_client_run", meta) sort_xml(config, key=lambda e: e.get('name'))"Generated config for %s in %.03f seconds" % (client, time.time() - start)) return config
[docs] def HandleEvent(self, event): """ Handle a change in the Bcfg2 config file. :param event: The event to handle :type event: Bcfg2.Server.FileMonitor.Event """ if event.filename != self.cfile: self.logger.error("Got event for unknown file: %s" % event.filename) return if event.code2str() == 'deleted': return self.setup.reparse() self.expire_caches_by_type(Bcfg2.Server.Plugin.Metadata)
[docs] def block_for_fam_events(self, handle_events=False): """ Block until all fam events have been handleed, optionally handling events as well. (Setting ``handle_events=True`` is useful for local server cores that don't spawn an event handling thread.)""" slept = 0 log_interval = 3 if handle_events: self.fam.handle_events_in_interval(1) slept += 1 if self.setup['fam_blocking']: time.sleep(1) slept += 1 while self.fam.pending() != 0: time.sleep(1) slept += 1 if slept % log_interval == 0: self.logger.debug("Sleeping to handle FAM events...") self.logger.debug("Slept %s seconds while handling FAM events" % slept)
[docs] def run(self): """ Run the server core. This calls :func:`_daemonize` (or :func:`_drop_privileges` if not in daemon mode), :func:`_run`, starts the :attr:`fam_thread`, and calls :func:`_block`, but note that it is the responsibility of the server core implementation to call :func:`shutdown` under normal operation. This also handles creation of the directory containing the pidfile, if necessary. """ if self.setup['daemon']: # if we're dropping privs, then the pidfile is likely # /var/run/bcfg2-server/ or similar. # since some OSes clean directories out of /var/run on # reboot, we need to ensure that the directory containing # the pidfile exists and has the appropriate permissions piddir = os.path.dirname(self.setup['daemon']) if not os.path.exists(piddir): os.makedirs(piddir) os.chown(piddir, self.setup['daemon_uid'], self.setup['daemon_gid']) os.chmod(piddir, 493) # 0775 if not self._daemonize(): return False # rewrite $HOME. pulp stores its auth creds in ~/.pulp, so # this is necessary to make that work when privileges are # dropped os.environ['HOME'] = pwd.getpwuid(self.setup['daemon_uid'])[5] else: if os.getuid() == 0: self._drop_privileges() os.umask(int(self.setup['umask'], 8)) if not self._run(): self.shutdown() return False try: self.load_plugins() self.fam.start() self.fam_thread.start() self.fam.AddMonitor(self.cfile, self) if self.perflog_thread is not None: self.perflog_thread.start() for plug in self.plugins_by_type(Threaded): plug.start_threads() if self.debug_flag: self.set_debug(None, self.debug_flag) self.block_for_fam_events() self._block() except: self.shutdown() raise
[docs] def _daemonize(self): """ Daemonize the server and write the pidfile. This must be overridden by a core implementation. """ raise NotImplementedError
[docs] def _drop_privileges(self): """ This is called if not daemonized and running as root to drop the privileges to the configured daemon_uid and daemon_gid. """ daemon.daemon.change_process_owner( self.setup['daemon_uid'], self.setup['daemon_gid']) self.logger.debug("Dropped privileges to %s:%s." % (os.getuid(), os.getgid()))
[docs] def _run(self): """ Start up the server; this method should return immediately. This must be overridden by a core implementation. """ raise NotImplementedError
[docs] def _block(self): """ Enter the infinite loop. This method should not return until the server is killed. This must be overridden by a core implementation. """ raise NotImplementedError
[docs] def GetDecisions(self, metadata, mode): """ Get the decision list for a client. :param metadata: Client metadata to get the decision list for :type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata :param mode: The decision mode ("whitelist" or "blacklist") :type mode: string :returns: list of Decision tuples ``(<entry tag>, <entry name>)`` """ self.logger.debug("Getting decision list for %s" % metadata.hostname) result = [] for plugin in self.plugins_by_type(Decision): try: result.extend(plugin.GetDecisions(metadata, mode)) except: self.logger.error("Plugin: %s failed to generate decision list" %, exc_info=1) return result
[docs] def build_metadata(self, client_name): """ Build initial client metadata for a client :param client_name: The name of the client to build metadata for :type client_name: string :returns: :class:`Bcfg2.Server.Plugins.Metadata.ClientMetadata` """ if not hasattr(self, 'metadata'): # some threads start before metadata is even loaded raise MetadataRuntimeError("Metadata not loaded yet") if self.metadata_cache_mode == 'initial': # the Metadata plugin handles loading the cached data if # we're only caching the initial metadata object imd = None else: imd = self.metadata_cache.get(client_name, None) if not imd: self.logger.debug("Building metadata for %s" % client_name) try: imd = self.metadata.get_initial_metadata(client_name) except MetadataConsistencyError: self.critical_error( "Client metadata resolution error for %s: %s" % (client_name, sys.exc_info()[1])) connectors = self.plugins_by_type(Connector) for conn in connectors: groups = conn.get_additional_groups(imd) groupnames = [] for group in groups: if hasattr(group, "name"): groupname = if groupname in self._dynamic_groups: if self._dynamic_groups[groupname] == self.metadata.groups[groupname] = group else: self.logger.warning( "Refusing to clobber dynamic group %s " "defined by %s" % (self._dynamic_groups[groupname], groupname)) elif groupname in self.metadata.groups: # not recorded as a dynamic group, but # present in metadata.groups -- i.e., a # static group self.logger.warning( "Refusing to clobber predefined group %s" % groupname) else: self.metadata.groups[groupname] = group self._dynamic_groups[groupname] = groupnames.append(groupname) else: groupnames.append(group) self.metadata.merge_additional_groups(imd, groupnames) for conn in connectors: data = conn.get_additional_data(imd) self.metadata.merge_additional_data(imd,, data) imd.query.by_name = self.build_metadata if self.metadata_cache_mode in ['cautious', 'aggressive']: self.metadata_cache[client_name] = imd else: self.logger.debug("Using cached metadata object for %s" % client_name) return imd
[docs] def process_statistics(self, client_name, statistics): """ Process uploaded statistics for client. :param client_name: The name of the client to process statistics for :type client_name: string :param statistics: The statistics document to process :type statistics: lxml.etree._Element """ self.logger.debug("Processing statistics for %s" % client_name) meta = self.build_metadata(client_name) state = statistics.find(".//Statistics") if state.get('version') >= '2.0': for plugin in self.plugins_by_type(Statistics): try: plugin.process_statistics(meta, statistics) except: self.logger.error("Plugin %s failed to process stats from " "%s" % (, meta.hostname), exc_info=1)"Client %s reported state %s" % (client_name, state.get('state'))) self.client_run_hook("end_statistics", meta)
[docs] def resolve_client(self, address, cleanup_cache=False, metadata=True): """ Given a client address, get the client hostname and optionally metadata. :param address: The address pair of the client to get the canonical hostname for. :type address: tuple of (<ip address>, <hostname>) :param cleanup_cache: Tell the :class:`Bcfg2.Server.Plugin.interfaces.Metadata` plugin in :attr:`metadata` to clean up any client or session cache it might keep :type cleanup_cache: bool :param metadata: Build a :class:`Bcfg2.Server.Plugins.Metadata.ClientMetadata` object for this client as well. This is offered for convenience. :type metadata: bool :returns: tuple - If ``metadata`` is False, returns ``(<canonical hostname>, None)``; if ``metadata`` is True, returns ``(<canonical hostname>, <client metadata object>)`` """ try: client = self.metadata.resolve_client(address, cleanup_cache=cleanup_cache) if metadata: meta = self.build_metadata(client) else: meta = None except MetadataConsistencyError: err = sys.exc_info()[1] self.critical_error("Client metadata resolution error for %s: %s" % (address[0], err)) except MetadataRuntimeError: err = sys.exc_info()[1] self.critical_error('Metadata system runtime failure for %s: %s' % (address[0], err)) return (client, meta)
[docs] def critical_error(self, message): """ Log an error with its traceback and return an XML-RPC fault to the client. :param message: The message to log and return to the client :type message: string :raises: :exc:`xmlrpclib.Fault` """ self.logger.error(message, exc_info=1) raise xmlrpclib.Fault(xmlrpclib.APPLICATION_ERROR, "Critical failure: %s" % message)
def _get_rmi_objects(self): """ Get a dict (name: object) of all objects that may have RMI calls. Currently, that includes all plugins and the FAM. """ rv = {self.fam.__class__.__name__: self.fam} rv.update(self.plugins) return rv def _get_rmi(self): """ Get a list of RMI calls exposed by plugins """ rmi = dict() for pname, pinst in self._get_rmi_objects().items(): for mname in pinst.__rmi__: rmi["%s.%s" % (pname, mname)] = getattr(pinst, mname) return rmi def _resolve_exposed_method(self, method_name): """ Resolve a method name to the callable that implements that method. :param method_name: Name of the method to resolve :type method_name: string :returns: callable """ try: func = getattr(self, method_name) except AttributeError: raise NoExposedMethod(method_name) if not getattr(func, "exposed", False): raise NoExposedMethod(method_name) return func # XMLRPC handlers start here @exposed
[docs] def listMethods(self, address): # pylint: disable=W0613 """ List all exposed methods, including plugin RMI. :param address: Client (address, hostname) pair :type address: tuple :returns: list of exposed method names """ methods = [name for name, func in inspect.getmembers(self, callable) if getattr(func, "exposed", False)] methods.extend(self._get_rmi().keys()) return methods
[docs] def methodHelp(self, address, method_name): # pylint: disable=W0613 """ Get help from the docstring of an exposed method :param address: Client (address, hostname) pair :type address: tuple :param method_name: The name of the method to get help on :type method_name: string :returns: string - The help message from the method's docstring """ try: func = self._resolve_exposed_method(method_name) except NoExposedMethod: return "" return func.__doc__
@exposed @track_statistics() @close_db_connection
[docs] def DeclareVersion(self, address, version): """ Declare the client version. :param address: Client (address, hostname) pair :type address: tuple :param version: The client's declared version :type version: string :returns: bool - True on success :raises: :exc:`xmlrpclib.Fault` """ client = self.resolve_client(address, metadata=False)[0] self.logger.debug("%s is running Bcfg2 client version %s" % (client, version)) try: self.metadata.set_version(client, version) except (MetadataConsistencyError, MetadataRuntimeError): err = sys.exc_info()[1] self.critical_error("Unable to set version for %s: %s" % (client, err)) return True
@exposed @close_db_connection
[docs] def GetProbes(self, address): """ Fetch probes for the client. :param address: Client (address, hostname) pair :type address: tuple :returns: lxml.etree._Element - XML tree describing probes for this client :raises: :exc:`xmlrpclib.Fault` """ resp = lxml.etree.Element('probes') client, metadata = self.resolve_client(address, cleanup_cache=True) self.logger.debug("Getting probes for %s" % client) try: for plugin in self.plugins_by_type(Probing): for probe in plugin.GetProbes(metadata): resp.append(probe) self.logger.debug("Sending probe list to %s" % client) return lxml.etree.tostring(resp, xml_declaration=False).decode('UTF-8') except: err = sys.exc_info()[1] self.critical_error("Error determining probes for %s: %s" % (client, err))
@exposed @close_db_connection
[docs] def RecvProbeData(self, address, probedata): """ Receive probe data from clients. :param address: Client (address, hostname) pair :type address: tuple :returns: bool - True on success :raises: :exc:`xmlrpclib.Fault` """ client, metadata = self.resolve_client(address) self.logger.debug("Receiving probe data from %s" % client) if self.metadata_cache_mode == 'cautious': # clear the metadata cache right after building the # metadata object; that way the cache is cleared for any # new probe data that's received, but the metadata object # that's created for RecvProbeData doesn't get cached. # I.e., the next metadata object that's built, after probe # data is processed, is cached. self.expire_caches_by_type(Bcfg2.Server.Plugin.Metadata) try: xpdata = lxml.etree.XML(probedata.encode('utf-8'), parser=Bcfg2.Server.XMLParser) except lxml.etree.XMLSyntaxError: err = sys.exc_info()[1] self.critical_error("Failed to parse probe data from client %s: %s" % (client, err)) sources = [] for data in xpdata: source = data.get('source') if source not in sources: if source not in self.plugins: self.logger.warning("Failed to locate plugin %s" % source) continue sources.append(source) for source in sources: datalist = [data for data in xpdata if data.get('source') == source] try: self.plugins[source].ReceiveData(metadata, datalist) except: err = sys.exc_info()[1] self.critical_error("Failed to process probe data from client " "%s: %s" % (client, err)) return True
@exposed @close_db_connection
[docs] def AssertProfile(self, address, profile): """ Set profile for a client. :param address: Client (address, hostname) pair :type address: tuple :returns: bool - True on success :raises: :exc:`xmlrpclib.Fault` """ client = self.resolve_client(address, metadata=False)[0] self.logger.debug("%s sets its profile to %s" % (client, profile)) try: self.metadata.set_profile(client, profile, address) except (MetadataConsistencyError, MetadataRuntimeError): err = sys.exc_info()[1] self.critical_error("Unable to assert profile for %s: %s" % (client, err)) return True
@exposed @close_db_connection
[docs] def GetConfig(self, address): """ Build config for a client by calling :func:`BuildConfiguration`. :param address: Client (address, hostname) pair :type address: tuple :returns: lxml.etree._Element - The full configuration document for the client :raises: :exc:`xmlrpclib.Fault` """ client = self.resolve_client(address)[0] try: config = self.BuildConfiguration(client) return lxml.etree.tostring(config, xml_declaration=False).decode('UTF-8') except MetadataConsistencyError: self.critical_error("Metadata consistency failure for %s" % client)
@exposed @close_db_connection
[docs] def RecvStats(self, address, stats): """ Act on statistics upload with :func:`process_statistics`. :param address: Client (address, hostname) pair :type address: tuple :returns: bool - True on success :raises: :exc:`xmlrpclib.Fault` """ client = self.resolve_client(address)[0] sdata = lxml.etree.XML(stats.encode('utf-8'), parser=Bcfg2.Server.XMLParser) self.process_statistics(client, sdata) return True
[docs] def authenticate(self, cert, user, password, address): """ Authenticate a client connection with :func:`Bcfg2.Server.Plugin.interfaces.Metadata.AuthenticateConnection`. :param cert: an x509 certificate :type cert: dict :param user: The username of the user trying to authenticate :type user: string :param password: The password supplied by the client :type password: string :param address: An address pair of ``(<ip address>, <hostname>)`` :type address: tuple :return: bool - True if the authenticate succeeds, False otherwise """ if acert = cert else: # No ca, so no cert validation can be done acert = None return self.metadata.AuthenticateConnection(acert, user, password, address)
@exposed @close_db_connection
[docs] def GetDecisionList(self, address, mode): """ Get the decision list for the client with :func:`GetDecisions`. :param address: Client (address, hostname) pair :type address: tuple :returns: list of decision tuples :raises: :exc:`xmlrpclib.Fault` """ metadata = self.resolve_client(address)[1] return self.GetDecisions(metadata, mode)
[docs] def database_available(self): """ True if the database is configured and available, False otherwise. """ return self._database_available
[docs] def get_statistics(self, _): """ Get current statistics about component execution from :attr:`Bcfg2.Statistics.stats`. :returns: dict - The statistics data as returned by :func:`Bcfg2.Statistics.Statistics.display` """ return Bcfg2.Statistics.stats.display()
[docs] def toggle_debug(self, address): """ Toggle debug status of the FAM and all plugins :param address: Client (address, hostname) pair :type address: tuple :returns: bool - The new debug state of the FAM """ return self.set_debug(address, not self.debug_flag)
[docs] def toggle_core_debug(self, address): """ Toggle debug status of the server core :param address: Client (address, hostname) pair :type address: tuple :returns: bool - The new debug state of the FAM """ return self.set_core_debug(address, not self.debug_flag)
[docs] def toggle_fam_debug(self, address): """ Toggle debug status of the FAM :returns: bool - The new debug state of the FAM """ self.logger.warning("Deprecated method set_fam_debug called by %s" % address[0]) return "This method is deprecated and will be removed in a future " + \ "release\n%s" % self.fam.toggle_debug()
[docs] def set_debug(self, address, debug): """ Explicitly set debug status of the FAM and all plugins :param address: Client (address, hostname) pair :type address: tuple :param debug: The new debug status. This can either be a boolean, or a string describing the state (e.g., "true" or "false"; case-insensitive) :type debug: bool or string :returns: bool - The new debug state """ if debug not in [True, False]: debug = debug.lower() == "true" for plugin in self.plugins.values(): plugin.set_debug(debug) rv = self.set_core_debug(address, debug) return self.fam.set_debug(debug) and rv
[docs] def set_core_debug(self, _, debug): """ Explicity set debug status of the server core :param debug: The new debug status. This can either be a boolean, or a string describing the state (e.g., "true" or "false"; case-insensitive) :type debug: bool or string :returns: bool - The new debug state of the FAM """ if debug not in [True, False]: debug = debug.lower() == "true" self.debug_flag = debug"Core: debug = %s" % debug) levels = self._loglevels[self.debug_flag] for handler in logging.root.handlers: try: level = levels.get(, levels['default']) self.logger.debug("Setting %s log handler to %s" % (, logging.getLevelName(level))) except AttributeError: level = levels['default'] self.logger.debug("Setting unknown log handler %s to %s" % (handler, logging.getLevelName(level))) handler.setLevel(level) return self.debug_flag
[docs] def set_fam_debug(self, address, debug): """ Explicitly set debug status of the FAM :param debug: The new debug status of the FAM. This can either be a boolean, or a string describing the state (e.g., "true" or "false"; case-insensitive) :type debug: bool or string :returns: bool - The new debug state of the FAM """ if debug not in [True, False]: debug = debug.lower() == "true" self.logger.warning("Deprecated method set_fam_debug called by %s" % address[0]) return "This method is deprecated and will be removed in a future " + \ "release\n%s" % self.fam.set_debug(debug)