""" 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.Server
import Bcfg2.Logger
import Bcfg2.Options
import Bcfg2.DBSettings
import Bcfg2.Server.Statistics
import Bcfg2.Server.FileMonitor
from itertools import chain
from Bcfg2.Server.Cache import Cache
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.Statistics import track_statistics
try:
from django.core.exceptions import ImproperlyConfigured
import django
import django.conf
HAS_DJANGO = True
except ImportError:
HAS_DJANGO = False
try:
import psyco
psyco.full()
except ImportError:
pass
[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"""
func.exposed = 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
self.logger.debug("%s: Closing database connection" %
threading.current_thread().getName())
if django.VERSION[0] == 1 and django.VERSION[1] >= 7:
for connection in django.db.connections.all():
connection.close()
else:
django.db.close_connection() # pylint: disable=E1101
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. """
[docs]class DefaultACL(Plugin, ClientACLs):
""" Default ACL 'plugin' that provides security by default. This
is only loaded if no other ClientACLs plugin is enabled. """
create = False
def __init__(self, core):
Bcfg2.Server.Plugin.Plugin.__init__(self, core)
Bcfg2.Server.Plugin.ClientACLs.__init__(self)
[docs] def check_acl_ip(self, address, rmi):
return (("." not in rmi and
not rmi.endswith("_debug") and
rmi != 'get_statistics' and
rmi != 'expire_metadata_cache') or
address[0] == "127.0.0.1")
# in core we frequently want to catch all exceptions, regardless of
# type, so disable the pylint rule that catches that.
# pylint: disable=W0702
[docs]class Core(object):
""" The server core is the container for all Bcfg2 server logic
and modules. All core implementations must inherit from
``Core``. """
options = [
Bcfg2.Options.Common.plugins,
Bcfg2.Options.Common.repository,
Bcfg2.Options.Common.filemonitor,
Bcfg2.Options.BooleanOption(
"--no-fam-blocking", cf=('server', 'fam_blocking'),
dest="fam_blocking", default=True,
help='FAM blocks on startup until all events are processed'),
Bcfg2.Options.BooleanOption(
cf=('logging', 'performance'), dest="perflog",
help="Periodically log performance statistics"),
Bcfg2.Options.Option(
cf=('logging', 'performance_interval'), default=300.0,
type=Bcfg2.Options.Types.timeout,
help="Performance statistics logging interval in seconds"),
Bcfg2.Options.Option(
cf=('caching', 'client_metadata'), dest='client_metadata_cache',
default='off',
choices=['off', 'on', 'initial', 'cautious', 'aggressive'])]
#: The name of this server core. This can be overridden by core
#: implementations to provide a more specific name.
name = "Core"
def __init__(self): # pylint: disable=R0912,R0915
"""
.. automethod:: _run
.. automethod:: _block
.. -----
.. automethod:: _file_monitor_thread
.. automethod:: _perflog_thread
"""
# Record the core as a module variable
Bcfg2.Server.core = self
#: 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=Bcfg2.Logger.default_log_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 Bcfg2.Options.setup.debug:
self.set_core_debug(None, Bcfg2.Options.setup.debug)
try:
#: The :class:`Bcfg2.Server.FileMonitor.FileMonitor`
#: object used by the core to monitor for Bcfg2 data
#: changes.
self.fam = Bcfg2.Server.FileMonitor.get_fam()
except IOError:
msg = "Failed to instantiate fam driver %s" % \
Bcfg2.Options.setup.filemonitor
self.logger.error(msg, exc_info=1)
raise CoreInitError(msg)
#: Path to bcfg2.conf
self.cfile = Bcfg2.Options.setup.config
#: 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'
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()
# mapping of group name => plugin name to record where groups
# that are created by Connector plugins came from
self._dynamic_groups = dict()
#: The FAM :class:`threading.Thread`,
#: :func:`_file_monitor_thread`
self.fam_thread = \
threading.Thread(name="%sFAMThread" %
Bcfg2.Options.setup.filemonitor.__name__,
target=self._file_monitor_thread)
#: The :class:`threading.Thread` that reports performance
#: statistics to syslog.
self.perflog_thread = None
if Bcfg2.Options.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.Server.Cache.Cache` object for caching client
#: metadata
self.metadata_cache = Cache("Metadata")
#: Whether or not it's possible to use the Django database
#: backend for plugins that have that capability
self._database_available = False
if HAS_DJANGO:
try:
Bcfg2.DBSettings.sync_databases(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("Updating database %s failed: %s" %
(Bcfg2.Options.setup.db_name,
sys.exc_info()[1]))
def __str__(self):
return self.__class__.__name__
[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, p.name))
[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(Bcfg2.Options.setup.performance_interval)
if not self.terminate.isSet():
for name, stats in self.get_statistics(None).items():
self.logger.info("Performance statistics: "
"%s min=%.06f, max=%.06f, average=%.06f, "
"count=%d" % ((name, ) + stats))
self.logger.info("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():
if famfd:
select.select([famfd], [], [], 2)
elif not self.fam.pending():
terminate.wait(15)
if self.fam.pending():
try:
self._update_vcs_revision()
except:
self.logger.error("Error updating VCS revision: %s" %
sys.exc_info()[1])
try:
self.fam.handle_event_set(self.lock)
except:
self.logger.error("Error handling event set: %s" %
sys.exc_info()[1])
self.logger.info("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" %
(plugin.name, 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:`Bcfg2.Server.Core.BaseCore.run` """
for plugin in Bcfg2.Options.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 deprecated and experimental plugins
expl = []
depr = []
for plug in list(self.plugins.values()):
if plug.experimental:
expl.append(plug)
if plug.deprecated:
depr.append(plug)
if expl:
self.logger.info("Loading experimental plugin(s): %s" %
(" ".join([x.name for x in expl])))
self.logger.info("NOTE: Interfaces subject to change")
if depr:
self.logger.info("Loading deprecated plugin(s): %s" %
(" ".join([x.name 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")
# ensure that an ACL plugin is loaded
if not self.plugins_by_type(Bcfg2.Server.Plugin.ClientACLs):
self.init_plugin(DefaultACL)
[docs] def init_plugin(self, plugin):
""" Import and instantiate a single plugin. The plugin is
stored to :attr:`plugins`.
:param plugin: The plugin class to load.
:type plugin: type
:returns: None
"""
self.logger.debug("Loading plugin %s" % plugin.name)
# Blacklist conflicting plugins
cplugs = [conflict for conflict in plugin.conflicts
if conflict in self.plugins]
self.plugin_blacklist[plugin.name] = cplugs
try:
self.plugins[plugin.name] = plugin(self)
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] @close_db_connection
def shutdown(self):
""" Perform plugin and FAM shutdown tasks. """
if not self._running:
self.logger.debug("%s: Core already shut down" % self.name)
return
self.logger.info("%s: Shutting down core..." % self.name)
if not self.terminate.isSet():
self.terminate.set()
self._running = False
self.fam.shutdown()
self.logger.info("%s: FAM shut down" % self.name)
for plugin in list(self.plugins.values()):
plugin.shutdown()
self.logger.info("%s: All plugins shut down" % self.name)
@property
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 = Bcfg2.Options.setup.client_metadata_cache
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.Server.Statistics.stats.add_value(
"%s:client_run_hook:%s" %
(self.__class__.__name__, hook),
time.time() - start)
[docs] @track_statistics()
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" %
(plugin.name, err))
raise
except:
self.logger.error("Plugin %s: unexpected structure validation "
"failure" % plugin.name, exc_info=1)
[docs] @track_statistics()
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" %
(plugin.name, err.message))
raise
except:
self.logger.error("Plugin %s: unexpected goal validation "
"failure" % plugin.name, exc_info=1)
[docs] @track_statistics()
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' or b.tag == 'Independent']
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] @track_statistics()
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] @track_statistics()
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([gen.name 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.Server.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=str(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'))
self.logger.info("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() in ['deleted', 'exists']:
# ignore config file deletion, and ignore the initial
# 'exists' event as well. we've already parsed options on
# startup, we don't need to parse them twice.
return
Bcfg2.Options.get_parser().reparse()
self.metadata_cache.expire()
[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 Bcfg2.Options.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:`_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 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()
self.block_for_fam_events()
self._block()
except:
self.shutdown()
raise
[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"
% plugin.name, exc_info=1)
return result
[docs] @track_statistics()
def check_acls(self, address, rmi):
""" Check client IP address and metadata object against all
:class:`Bcfg2.Server.Plugin.interfaces.ClientACLs` plugins.
If any ACL plugin denies access, then access is denied. ACLs
are checked in two phases: First, with the client IP address;
and second, with the client metadata object. This lets an ACL
interface do a quick rejection based on IP before metadata is
ever built.
:param address: The address pair of the client to check ACLs for
:type address: tuple of (<ip address>, <port>)
:param rmi: The fully-qualified name of the RPC call
:param rmi: string
:returns: bool
"""
plugins = self.plugins_by_type(Bcfg2.Server.Plugin.ClientACLs)
try:
ip_checks = [p.check_acl_ip(address, rmi) for p in plugins]
except:
self.logger.error("Unexpected error checking ACLs for %s for %s: "
"%s" % (address[0], rmi, sys.exc_info()[1]))
return False # failsafe
if all(ip_checks):
# if all ACL plugins return True (allow), then allow
self.logger.debug("Client %s passed IP-based ACL checks for %s" %
(address[0], rmi))
return True
elif False in ip_checks:
# if any ACL plugin returned False (deny), then deny
self.logger.warning("Client %s failed IP-based ACL checks for %s" %
(address[0], rmi))
return False
# else, no plugins returned False, but not all plugins
# returned True, so some plugin returned None (defer), so
# defer.
client, metadata = self.resolve_client(address)
try:
rv = all(p.check_acl_metadata(metadata, rmi) for p in plugins)
if rv:
self.logger.debug(
"Client %s passed metadata ACL checks for %s" %
(metadata.hostname, rmi))
else:
self.logger.warning(
"Client %s failed metadata ACL checks for %s" %
(metadata.hostname, rmi))
return rv
except:
self.logger.error("Unexpected error checking ACLs for %s for %s: "
"%s" % (client, rmi, sys.exc_info()[1]))
return False # failsafe
[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" % (plugin.name, meta.hostname),
exc_info=1)
self.logger.info("Client %s reported state %s" % (client_name,
state.get('state')))
self.client_run_hook("end_statistics", meta)
[docs] @track_statistics()
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>, <port>)
: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
[docs] @exposed
def listMethods(self, address): # pylint: disable=W0613
""" List all exposed methods, including plugin RMI.
:param address: Client (address, port) 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) and
self.check_acls(address, name))]
methods.extend([m for m in self._get_rmi().keys()
if self.check_acls(address, m)])
return methods
[docs] @exposed
def methodHelp(self, address, method_name): # pylint: disable=W0613
""" Get help from the docstring of an exposed method
:param address: Client (address, port) 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__
[docs] @exposed
@track_statistics()
@close_db_connection
def DeclareVersion(self, address, version):
""" Declare the client version.
:param address: Client (address, port) 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
[docs] @exposed
@close_db_connection
def GetProbes(self, address):
""" Fetch probes for the client.
:param address: Client (address, port) 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))
[docs] @exposed
@close_db_connection
def RecvProbeData(self, address, probedata):
""" Receive probe data from clients.
:param address: Client (address, port) 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.metadata_cache.expire(client)
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
[docs] @exposed
@close_db_connection
def AssertProfile(self, address, profile):
""" Set profile for a client.
:param address: Client (address, port) 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
[docs] @exposed
@close_db_connection
def GetConfig(self, address):
""" Build config for a client by calling
:func:`BuildConfiguration`.
:param address: Client (address, port) 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)
[docs] @exposed
@close_db_connection
def RecvStats(self, address, stats):
""" Act on statistics upload with :func:`process_statistics`.
:param address: Client (address, port) 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] @exposed
@close_db_connection
def GetDecisionList(self, address, mode):
""" Get the decision list for the client with :func:`GetDecisions`.
:param address: Client (address, port) pair
:type address: tuple
:returns: list of decision tuples
:raises: :exc:`xmlrpclib.Fault`
"""
metadata = self.resolve_client(address)[1]
return self.GetDecisions(metadata, mode)
@property
def database_available(self):
""" True if the database is configured and available, False
otherwise. """
return self._database_available
[docs] @exposed
def get_statistics(self, _):
""" Get current statistics about component execution from
:attr:`Bcfg2.Server.Statistics.stats`.
:returns: dict - The statistics data as returned by
:func:`Bcfg2.Server.Statistics.Statistics.display` """
return Bcfg2.Server.Statistics.stats.display()
[docs] @exposed
def toggle_debug(self, address):
""" Toggle debug status of the FAM and all plugins
:param address: Client (address, port) pair
:type address: tuple
:returns: bool - The new debug state of the FAM
"""
return self.set_debug(address, not self.debug_flag)
[docs] @exposed
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] @exposed
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] @exposed
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] @exposed
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
self.logger.info("Core: debug = %s" % debug)
levels = self._loglevels[self.debug_flag]
for handler in logging.root.handlers:
try:
level = levels.get(handler.name, levels['default'])
self.logger.debug("Setting %s log handler to %s" %
(handler.name, 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] @exposed
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)
[docs]class NetworkCore(Core):
""" A server core that actually listens on the network, can be
daemonized, etc."""
options = Core.options + [
Bcfg2.Options.Common.daemon, Bcfg2.Options.Common.syslog,
Bcfg2.Options.Common.location, Bcfg2.Options.Common.ssl_ca,
Bcfg2.Options.Common.protocol,
Bcfg2.Options.PathOption(
'--ssl-key', cf=('communication', 'key'), dest="key",
help='Path to SSL key',
default="/etc/pki/tls/private/bcfg2.key"),
Bcfg2.Options.PathOption(
cf=('communication', 'certificate'), dest="cert",
help='Path to SSL certificate',
default="/etc/pki/tls/certs/bcfg2.crt"),
Bcfg2.Options.BooleanOption(
'--listen-all', cf=('server', 'listen_all'), default=False,
help="Listen on all interfaces"),
Bcfg2.Options.Option(
cf=('server', 'umask'), default='0077', help='Server umask',
type=Bcfg2.Options.Types.octal),
Bcfg2.Options.Option(
cf=('server', 'user'), default=0, dest='daemon_uid',
type=Bcfg2.Options.Types.username,
help="User to run the server daemon as"),
Bcfg2.Options.Option(
cf=('server', 'group'), default=0, dest='daemon_gid',
type=Bcfg2.Options.Types.groupname,
help="Group to run the server daemon as")]
def __init__(self):
Core.__init__(self)
#: The CA that signed the server cert
self.ca = Bcfg2.Options.setup.ca
if self._database_available:
db_settings = django.conf.settings.DATABASES['default']
if (Bcfg2.Options.setup.daemon and
Bcfg2.Options.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
try:
os.chown(db_settings['NAME'],
Bcfg2.Options.setup.daemon_uid,
Bcfg2.Options.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))
__init__.__doc__ = Core.__init__.__doc__.split(".. -----")[0] + \
"\n.. automethod:: _daemonize\n"
def __str__(self):
if hasattr(Bcfg2.Options.setup, "server"):
return "%s(%s)" % (self.__class__.__name__,
Bcfg2.Options.setup.server)
else:
return Core.__str__(self)
[docs] def run(self):
""" Run the server core. This calls :func:`_daemonize` before
calling :func:`Bcfg2.Server.Core.Core.run` to run the server
core. """
if Bcfg2.Options.setup.daemon:
# if we're dropping privs, then the pidfile is likely
# /var/run/bcfg2-server/bcfg2-server.pid 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(Bcfg2.Options.setup.daemon)
if not os.path.exists(piddir):
os.makedirs(piddir)
os.chown(piddir,
Bcfg2.Options.setup.daemon_uid,
Bcfg2.Options.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(Bcfg2.Options.setup.daemon_uid)[5]
else:
os.umask(int(Bcfg2.Options.setup.umask, 8))
Core.run(self)
[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>, <port>)``
:type address: tuple
:return: bool - True if the authenticate succeeds, False otherwise
"""
if self.ca:
acert = cert
else:
# No ca, so no cert validation can be done
acert = None
return self.metadata.AuthenticateConnection(acert, user, password,
address)
[docs] def _daemonize(self):
""" Daemonize the server and write the pidfile. This must be
overridden by a core implementation. """
raise NotImplementedError
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(
Bcfg2.Options.setup.daemon_uid,
Bcfg2.Options.setup.daemon_gid)
self.logger.debug("Dropped privileges to %s:%s." %
(os.getuid(), os.getgid()))
