1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
|
""" Interface definitions for Bcfg2 server plugins """
import os
import sys
import copy
import threading
import lxml.etree
import Bcfg2.Server
from Bcfg2.Compat import Queue, Empty, Full, cPickle
from exceptions import *
from base import Plugin
class Generator(object):
""" Generator plugins contribute to literal client configurations.
That is, they generate entry contents.
An entry is generated in one of two ways:
#. The Bcfg2 core looks in the ``Entries`` dict attribute of the
plugin object. ``Entries`` is expected to be a dict whose keys
are entry tags (e.g., ``"Path"``, ``"Service"``, etc.) and
whose values are dicts; those dicts should map the ``name``
attribute of an entry to a callable that will be called to
generate the content. The callable will receive two arguments:
the abstract entry (as an lxml.etree._Element object), and the
client metadata object the entry is being generated for.
#. If the entry is not listed in ``Entries``, the Bcfg2 core calls
:func:`HandlesEntry`; if that returns True, then it calls
:func:`HandleEntry`.
"""
def HandlesEntry(self, entry, metadata):
""" HandlesEntry is the slow path method for routing
configuration binding requests. It is called if the
``Entries`` dict does not contain a method for binding the
entry.
:param entry: The entry to bind
:type entry: lxml.etree._Element
:param metadata: The client metadata
:type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata
:return: bool - Whether or not this plugin can handle the entry
:raises: :class:`Bcfg2.Server.Plugin.exceptions.PluginExecutionError`
"""
return False
def HandleEntry(self, entry, metadata):
""" HandlesEntry is the slow path method for binding
configuration binding requests. It is called if the
``Entries`` dict does not contain a method for binding the
entry, and :func:`HandlesEntry`
returns True.
:param entry: The entry to bind
:type entry: lxml.etree._Element
:param metadata: The client metadata
:type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata
:return: lxml.etree._Element - The fully bound entry
:raises: :class:`Bcfg2.Server.Plugin.exceptions.PluginExecutionError`
"""
return entry
class Structure(object):
""" Structure Plugins contribute to abstract client
configurations. That is, they produce lists of entries that will
be generated for a client. """
def BuildStructures(self, metadata):
""" Build a list of lxml.etree._Element objects that will be
added to the top-level ``<Configuration>`` tag of the client
configuration. Consequently, each object in the list returned
by ``BuildStructures()`` must consist of a container tag
(e.g., ``<Bundle>`` or ``<Independent>``) which contains the
entry tags. It must not return a list of entry tags.
:param metadata: The client metadata
:type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata
:return: list of lxml.etree._Element objects
"""
raise NotImplementedError
class Metadata(object):
"""Signal metadata capabilities for this plugin"""
def viz(self, hosts, bundles, key, only_client, colors):
""" Return a string containing a graphviz document that maps
out the Metadata for :ref:`bcfg2-admin viz <server-admin-viz>`
:param hosts: Include hosts in the graph
:type hosts: bool
:param bundles: Include bundles in the graph
:type bundles: bool
:param key: Include a key in the graph
:type key: bool
:param only_client: Only include data for the specified client
:type only_client: string
:param colors: Use the specified graphviz colors
:type colors: list of strings
:return: string
"""
return ''
def set_version(self, client, version):
""" Set the version for the named client to the specified
version string.
:param client: Hostname of the client
:type client: string
:param profile: Client Bcfg2 version
:type profile: string
:return: None
:raises: :class:`Bcfg2.Server.Plugin.exceptions.MetadataRuntimeError`,
:class:`Bcfg2.Server.Plugin.exceptions.MetadataConsistencyError`
"""
pass
def set_profile(self, client, profile, address):
""" Set the profile for the named client to the named profile
group.
:param client: Hostname of the client
:type client: string
:param profile: Name of the profile group
:type profile: string
:param address: Address pair of ``(<ip address>, <hostname>)``
:type address: tuple
:return: None
:raises: :class:`Bcfg2.Server.Plugin.exceptions.MetadataRuntimeError`,
:class:`Bcfg2.Server.Plugin.exceptions.MetadataConsistencyError`
"""
pass
def resolve_client(self, address, cleanup_cache=False):
""" Resolve the canonical name of this client. If this method
is not implemented, the hostname claimed by the client is
used. (This may be a security risk; it's highly recommended
that you implement ``resolve_client`` if you are writing a
Metadata plugin.)
:param address: Address pair of ``(<ip address>, <hostname>)``
:type address: tuple
:param cleanup_cache: Whether or not to remove expire the
entire client hostname resolution class
:type cleanup_cache: bool
:return: string - canonical client hostname
:raises: :class:`Bcfg2.Server.Plugin.exceptions.MetadataRuntimeError`,
:class:`Bcfg2.Server.Plugin.exceptions.MetadataConsistencyError`
"""
return address[1]
def AuthenticateConnection(self, cert, user, password, address):
""" Authenticate the given client.
: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 addresspair: An address pair of ``(<ip address>,
<hostname>)``
:type addresspair: tuple
:return: bool - True if the authenticate succeeds, False otherwise
"""
raise NotImplementedError
def get_initial_metadata(self, client_name):
""" Return a
:class:`Bcfg2.Server.Plugins.Metadata.ClientMetadata` object
that fully describes everything the Metadata plugin knows
about the named client.
:param client_name: The hostname of the client
:type client_name: string
:return: Bcfg2.Server.Plugins.Metadata.ClientMetadata
"""
raise NotImplementedError
def merge_additional_data(self, imd, source, data):
""" Add arbitrary data from a
:class:`Connector` plugin to the given
metadata object.
:param imd: An initial metadata object
:type imd: Bcfg2.Server.Plugins.Metadata.ClientMetadata
:param source: The name of the plugin providing this data
:type source: string
:param data: The data to add
:type data: any
:return: None
"""
raise NotImplementedError
def merge_additional_groups(self, imd, groups):
""" Add groups from a
:class:`Connector` plugin to the given
metadata object.
:param imd: An initial metadata object
:type imd: Bcfg2.Server.Plugins.Metadata.ClientMetadata
:param groups: The groups to add
:type groups: list of strings
:return: None
"""
raise NotImplementedError
class Connector(object):
""" Connector plugins augment client metadata instances with
additional data, additional groups, or both. """
def get_additional_groups(self, metadata):
""" Return a list of additional groups for the given client.
:param metadata: The client metadata
:type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata
:return: list of strings
"""
return list()
def get_additional_data(self, metadata):
""" Return arbitrary additional data for the given
ClientMetadata object. By convention this is usually a dict
object, but doesn't need to be.
:param metadata: The client metadata
:type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata
:return: list of strings
"""
return dict()
class Probing(object):
""" Probing plugins can collect data from clients and process it.
"""
def GetProbes(self, metadata):
""" Return a list of probes for the given client. Each probe
should be an lxml.etree._Element object that adheres to
the following specification. Each probe must the following
attributes:
* ``name``: The unique name of the probe.
* ``source``: The origin of the probe; probably the name of
the plugin that supplies the probe.
* ``interpreter``: The command that will be run on the client
to interpret the probe script. Compiled (i.e.,
non-interpreted) probes are not supported.
The text of the XML tag should be the contents of the probe,
i.e., the code that will be run on the client.
:param metadata: The client metadata
:type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata
:return: list of lxml.etree._Element objects
"""
raise NotImplementedError
def ReceiveData(self, metadata, datalist):
""" Process data returned from the probes for the given
client. ``datalist`` is a list of lxml.etree._Element
objects, each of which is a single tag; the ``name`` attribute
holds the unique name of the probe that was run, and the text
contents of the tag hold the results of the probe.
:param metadata: The client metadata
:type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata
:param datalist: The probe data
:type datalist: list of lxml.etree._Element objects
:return: None
"""
raise NotImplementedError
class Statistics(Plugin):
""" Statistics plugins handle statistics for clients. In general,
you should avoid using Statistics and use
:class:`ThreadedStatistics` instead."""
def process_statistics(self, client, xdata):
""" Process the given XML statistics data for the specified
client.
:param metadata: The client metadata
:type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata
:param data: The statistics data
:type data: lxml.etree._Element
:return: None
"""
raise NotImplementedError
class ThreadedStatistics(Statistics, threading.Thread):
""" ThreadedStatistics plugins process client statistics in a
separate thread. """
def __init__(self, core, datastore):
Statistics.__init__(self, core, datastore)
threading.Thread.__init__(self)
# Event from the core signaling an exit
self.terminate = core.terminate
self.work_queue = Queue(100000)
self.pending_file = os.path.join(datastore, "etc",
"%s.pending" % self.name)
self.daemon = False
self.start()
def _save(self):
"""Save any pending data to a file."""
pending_data = []
try:
while not self.work_queue.empty():
(metadata, data) = self.work_queue.get_nowait()
try:
pending_data.append((metadata.hostname,
lxml.etree.tostring(data,
xml_declaration=False).decode("UTF-8")))
except:
err = sys.exc_info()[1]
self.logger.warning("Dropping interaction for %s: %s" %
(metadata.hostname, err))
except Empty:
pass
try:
savefile = open(self.pending_file, 'w')
cPickle.dump(pending_data, savefile)
savefile.close()
self.logger.info("Saved pending %s data" % self.name)
except:
err = sys.exc_info()[1]
self.logger.warning("Failed to save pending data: %s" % err)
def _load(self):
"""Load any pending data from a file."""
if not os.path.exists(self.pending_file):
return True
pending_data = []
try:
savefile = open(self.pending_file, 'r')
pending_data = cPickle.load(savefile)
savefile.close()
except Exception:
e = sys.exc_info()[1]
self.logger.warning("Failed to load pending data: %s" % e)
return False
for (pmetadata, pdata) in pending_data:
# check that shutdown wasnt called early
if self.terminate.isSet():
return False
try:
while True:
try:
metadata = self.core.build_metadata(pmetadata)
break
except MetadataRuntimeError:
pass
self.terminate.wait(5)
if self.terminate.isSet():
return False
self.work_queue.put_nowait((metadata,
lxml.etree.XML(pdata,
parser=Bcfg2.Server.XMLParser)))
except Full:
self.logger.warning("Queue.Full: Failed to load queue data")
break
except lxml.etree.LxmlError:
lxml_error = sys.exc_info()[1]
self.logger.error("Unable to load saved interaction: %s" %
lxml_error)
except MetadataConsistencyError:
self.logger.error("Unable to load metadata for save "
"interaction: %s" % pmetadata)
try:
os.unlink(self.pending_file)
except:
self.logger.error("Failed to unlink save file: %s" %
self.pending_file)
self.logger.info("Loaded pending %s data" % self.name)
return True
def run(self):
if not self._load():
return
while not self.terminate.isSet() and self.work_queue != None:
try:
(client, xdata) = self.work_queue.get(block=True, timeout=2)
except Empty:
continue
except Exception:
e = sys.exc_info()[1]
self.logger.error("ThreadedStatistics: %s" % e)
continue
self.handle_statistic(client, xdata)
if self.work_queue != None and not self.work_queue.empty():
self._save()
def process_statistics(self, metadata, data):
try:
self.work_queue.put_nowait((metadata, copy.copy(data)))
except Full:
self.logger.warning("%s: Queue is full. Dropping interactions." %
self.name)
def handle_statistic(self, metadata, data):
""" Process the given XML statistics data for the specified
client object. This differs from the
:func:`Statistics.process_statistics` method only in that
ThreadedStatistics first adds the data to a queue, and then
processes them in a separate thread.
:param metadata: The client metadata
:type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata
:param data: The statistics data
:type data: lxml.etree._Element
:return: None
"""
raise NotImplementedError
class PullSource(object):
def GetExtra(self, client):
return []
def GetCurrentEntry(self, client, e_type, e_name):
raise NotImplementedError
class PullTarget(object):
def AcceptChoices(self, entry, metadata):
raise NotImplementedError
def AcceptPullData(self, specific, new_entry, verbose):
raise NotImplementedError
class Decision(object):
""" Decision plugins produce decision lists for affecting which
entries are actually installed on clients. """
def GetDecisions(self, metadata, mode):
""" Return a list of tuples of ``(<entry type>, <entry
name>)`` to be used as the decision list for the given
client in the specified mode.
:param metadata: The client metadata
:type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata
:param mode: The decision mode ("whitelist" or "blacklist")
:type mode: string
:return: list of tuples
"""
raise NotImplementedError
class StructureValidator(object):
""" StructureValidator plugins can modify the list of structures
after it has been created but before the entries have been
concretely bound. """
def validate_structures(self, metadata, structures):
""" Given a list of structures (i.e., of tags that contain
entry tags), modify that list or the structures in it
in-place.
:param metadata: The client metadata
:type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata
:param config: A list of lxml.etree._Element objects
describing the structures for this client
:type config: list
:returns: None
:raises: :class:`Bcfg2.Server.Plugin.exceptions.ValidationError`
"""
raise NotImplementedError
class GoalValidator(object):
""" GoalValidator plugins can modify the concretely-bound configuration of
a client as a last stage before the configuration is sent to the
client. """
def validate_goals(self, metadata, config):
""" Given a monolithic XML document of the full configuration,
modify the document in-place.
:param metadata: The client metadata
:type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata
:param config: The full configuration for the client
:type config: lxml.etree._Element
:returns: None
:raises: :class:`Bcfg2.Server.Plugin.exceptions:ValidationError`
"""
raise NotImplementedError
class Version(object):
""" Version plugins interact with various version control systems. """
def get_revision(self):
""" Return the current revision of the Bcfg2 specification.
This will be included in the ``revision`` attribute of the
top-level tag of the XML configuration sent to the client.
:returns: string - the current version
"""
raise NotImplementedError
class ClientRunHooks(object):
""" ClientRunHooks can hook into various parts of a client run to
perform actions at various times without needing to pretend to be
a different plugin type. """
def start_client_run(self, metadata):
""" Invoked at the start of a client run, after all probe data
has been received and decision lists have been queried (if
applicable), but before the configuration is generated.
:param metadata: The client metadata object
:type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata
:returns: None
"""
pass
def end_client_run(self, metadata):
""" Invoked at the end of a client run, immediately after
:class:`GoalValidator` plugins have been run and just before
the configuration is returned to the client.
:param metadata: The client metadata object
:type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata
:returns: None
"""
pass
def end_statistics(self, metadata):
""" Invoked after statistics are processed for a client.
:param metadata: The client metadata object
:type metadata: Bcfg2.Server.Plugins.Metadata.ClientMetadata
:returns: None
"""
pass
|