juju/model.py

   1 import asyncio
   2 import collections
   3 import logging
   4 import re
   5 import weakref
   6 from concurrent.futures import CancelledError
   7 from functools import partial
   8
   9 import yaml
  10 from theblues import charmstore
  11
  12 from .client import client
  13 from .client import watcher
  14 from .client import connection
  15 from .delta import get_entity_delta
  16 from .delta import get_entity_class
  17 from .exceptions import DeadEntityException
  18 from .errors import JujuAPIError
  19
  20 log = logging.getLogger(__name__)
  21
  22
  23 class _Observer(object):
  24     """Wrapper around an observer callable.
  25
  26     This wrapper allows filter criteria to be associated with the
  27     callable so that it's only called for changes that meet the criteria.
  28
  29     """
  30     def __init__(self, callable_, entity_type, action, entity_id, predicate):
  31         self.callable_ = callable_
  32         self.entity_type = entity_type
  33         self.action = action
  34         self.entity_id = entity_id
  35         self.predicate = predicate
  36         if self.entity_id:
  37             self.entity_id = str(self.entity_id)
  38             if not self.entity_id.startswith('^'):
  39                 self.entity_id = '^' + self.entity_id
  40             if not self.entity_id.endswith('$'):
  41                 self.entity_id += '$'
  42
  43     async def __call__(self, delta, old, new, model):
  44         await self.callable_(delta, old, new, model)
  45
  46     def cares_about(self, delta):
  47         """Return True if this observer "cares about" (i.e. wants to be
  48         called) for a this delta.
  49
  50         """
  51         if (self.entity_id and delta.get_id() and
  52                 not re.match(self.entity_id, str(delta.get_id()))):
  53             return False
  54
  55         if self.entity_type and self.entity_type != delta.entity:
  56             return False
  57
  58         if self.action and self.action != delta.type:
  59             return False
  60
  61         if self.predicate and not self.predicate(delta):
  62             return False
  63
  64         return True
  65
  66
  67 class ModelObserver(object):
  68     async def __call__(self, delta, old, new, model):
  69         handler_name = 'on_{}_{}'.format(delta.entity, delta.type)
  70         method = getattr(self, handler_name, self.on_change)
  71         await method(delta, old, new, model)
  72
  73     async def on_change(self, delta, old, new, model):
  74         pass
  75
  76
  77 class ModelState(object):
  78     """Holds the state of the model, including the delta history of all
  79     entities in the model.
  80
  81     """
  82     def __init__(self, model):
  83         self.model = model
  84         self.state = dict()
  85
  86     def _live_entity_map(self, entity_type):
  87         """Return an id:Entity map of all the living entities of
  88         type ``entity_type``.
  89
  90         """
  91         return {
  92             entity_id: self.get_entity(entity_type, entity_id)
  93             for entity_id, history in self.state.get(entity_type, {}).items()
  94             if history[-1] is not None
  95         }
  96
  97     @property
  98     def applications(self):
  99         """Return a map of application-name:Application for all applications
 100         currently in the model.
 101
 102         """
 103         return self._live_entity_map('application')
 104
 105     @property
 106     def machines(self):
 107         """Return a map of machine-id:Machine for all machines currently in
 108         the model.
 109
 110         """
 111         return self._live_entity_map('machine')
 112
 113     @property
 114     def units(self):
 115         """Return a map of unit-id:Unit for all units currently in
 116         the model.
 117
 118         """
 119         return self._live_entity_map('unit')
 120
 121     def entity_history(self, entity_type, entity_id):
 122         """Return the history deque for an entity.
 123
 124         """
 125         return self.state[entity_type][entity_id]
 126
 127     def entity_data(self, entity_type, entity_id, history_index):
 128         """Return the data dict for an entity at a specific index of its
 129         history.
 130
 131         """
 132         return self.entity_history(entity_type, entity_id)[history_index]
 133
 134     def apply_delta(self, delta):
 135         """Apply delta to our state and return a copy of the
 136         affected object as it was before and after the update, e.g.:
 137
 138             old_obj, new_obj = self.apply_delta(delta)
 139
 140         old_obj may be None if the delta is for the creation of a new object,
 141         e.g. a new application or unit is deployed.
 142
 143         new_obj will never be None, but may be dead (new_obj.dead == True)
 144         if the object was deleted as a result of the delta being applied.
 145
 146         """
 147         history = (
 148             self.state
 149             .setdefault(delta.entity, {})
 150             .setdefault(delta.get_id(), collections.deque())
 151         )
 152
 153         history.append(delta.data)
 154         if delta.type == 'remove':
 155             history.append(None)
 156
 157         entity = self.get_entity(delta.entity, delta.get_id())
 158         return entity.previous(), entity
 159
 160     def get_entity(
 161             self, entity_type, entity_id, history_index=-1, connected=True):
 162         """Return an object instance representing the entity created or
 163         updated by ``delta``
 164
 165         """
 166         """
 167         log.debug(
 168             'Getting %s:%s at index %s',
 169             entity_type, entity_id, history_index)
 170         """
 171
 172         if history_index < 0 and history_index != -1:
 173             history_index += len(self.entity_history(entity_type, entity_id))
 174             if history_index < 0:
 175                 return None
 176
 177         try:
 178             self.entity_data(entity_type, entity_id, history_index)
 179         except IndexError:
 180             return None
 181
 182         entity_class = get_entity_class(entity_type)
 183         return entity_class(
 184             entity_id, self.model, history_index=history_index,
 185             connected=connected)
 186
 187
 188 class ModelEntity(object):
 189     """An object in the Model tree"""
 190
 191     def __init__(self, entity_id, model, history_index=-1, connected=True):
 192         """Initialize a new entity
 193
 194         :param entity_id str: The unique id of the object in the model
 195         :param model: The model instance in whose object tree this
 196             entity resides
 197         :history_index int: The index of this object's state in the model's
 198             history deque for this entity
 199         :connected bool: Flag indicating whether this object gets live updates
 200             from the model.
 201
 202         """
 203         self.entity_id = entity_id
 204         self.model = model
 205         self._history_index = history_index
 206         self.connected = connected
 207         self.connection = model.connection
 208
 209     def __getattr__(self, name):
 210         """Fetch object attributes from the underlying data dict held in the
 211         model.
 212
 213         """
 214         if self.data is None:
 215             raise DeadEntityException(
 216                 "Entity {}:{} is dead - its attributes can no longer be "
 217                 "accessed. Use the .previous() method on this object to get "
 218                 "a copy of the object at its previous state.".format(
 219                     self.entity_type, self.entity_id))
 220         return self.data[name]
 221
 222     def __bool__(self):
 223         return bool(self.data)
 224
 225     def on_change(self, callable_):
 226         """Add a change observer to this entity.
 227
 228         """
 229         self.model.add_observer(
 230             callable_, self.entity_type, 'change', self.entity_id)
 231
 232     def on_remove(self, callable_):
 233         """Add a remove observer to this entity.
 234
 235         """
 236         self.model.add_observer(
 237             callable_, self.entity_type, 'remove', self.entity_id)
 238
 239     @property
 240     def entity_type(self):
 241         """A string identifying the entity type of this object, e.g.
 242         'application' or 'unit', etc.
 243
 244         """
 245         return self.__class__.__name__.lower()
 246
 247     @property
 248     def current(self):
 249         """Return True if this object represents the current state of the
 250         entity in the underlying model.
 251
 252         This will be True except when the object represents an entity at a
 253         non-latest state in history, e.g. if the object was obtained by calling
 254         .previous() on another object.
 255
 256         """
 257         return self._history_index == -1
 258
 259     @property
 260     def dead(self):
 261         """Returns True if this entity no longer exists in the underlying
 262         model.
 263
 264         """
 265         return (
 266             self.data is None or
 267             self.model.state.entity_data(
 268                 self.entity_type, self.entity_id, -1) is None
 269         )
 270
 271     @property
 272     def alive(self):
 273         """Returns True if this entity still exists in the underlying
 274         model.
 275
 276         """
 277         return not self.dead
 278
 279     @property
 280     def data(self):
 281         """The data dictionary for this entity.
 282
 283         """
 284         return self.model.state.entity_data(
 285             self.entity_type, self.entity_id, self._history_index)
 286
 287     def previous(self):
 288         """Return a copy of this object as was at its previous state in
 289         history.
 290
 291         Returns None if this object is new (and therefore has no history).
 292
 293         The returned object is always "disconnected", i.e. does not receive
 294         live updates.
 295
 296         """
 297         return self.model.state.get_entity(
 298             self.entity_type, self.entity_id, self._history_index - 1,
 299             connected=False)
 300
 301     def next(self):
 302         """Return a copy of this object at its next state in
 303         history.
 304
 305         Returns None if this object is already the latest.
 306
 307         The returned object is "disconnected", i.e. does not receive
 308         live updates, unless it is current (latest).
 309
 310         """
 311         if self._history_index == -1:
 312             return None
 313
 314         new_index = self._history_index + 1
 315         connected = (
 316             new_index == len(self.model.state.entity_history(
 317                 self.entity_type, self.entity_id)) - 1
 318         )
 319         return self.model.state.get_entity(
 320             self.entity_type, self.entity_id, self._history_index - 1,
 321             connected=connected)
 322
 323     def latest(self):
 324         """Return a copy of this object at its current state in the model.
 325
 326         Returns self if this object is already the latest.
 327
 328         The returned object is always "connected", i.e. receives
 329         live updates from the model.
 330
 331         """
 332         if self._history_index == -1:
 333             return self
 334
 335         return self.model.state.get_entity(self.entity_type, self.entity_id)
 336
 337
 338 class Model(object):
 339     def __init__(self, loop=None):
 340         """Instantiate a new connected Model.
 341
 342         :param loop: an asyncio event loop
 343
 344         """
 345         self.loop = loop or asyncio.get_event_loop()
 346         self.connection = None
 347         self.observers = weakref.WeakValueDictionary()
 348         self.state = ModelState(self)
 349         self._watcher_task = None
 350         self._watch_shutdown = asyncio.Event(loop=loop)
 351         self._watch_received = asyncio.Event(loop=loop)
 352         self._charmstore = CharmStore(self.loop)
 353
 354     async def connect_current(self):
 355         """Connect to the current Juju model.
 356
 357         """
 358         self.connection = await connection.Connection.connect_current()
 359         self._watch()
 360         await self._watch_received.wait()
 361
 362     async def disconnect(self):
 363         """Shut down the watcher task and close websockets.
 364
 365         """
 366         self._stop_watching()
 367         if self.connection and self.connection.is_open:
 368             await self._watch_shutdown.wait()
 369             log.debug('Closing model connection')
 370             await self.connection.close()
 371             self.connection = None
 372
 373     def all_units_idle(self):
 374         """Return True if all units are idle.
 375
 376         """
 377         for unit in self.units.values():
 378             unit_status = unit.data['agent-status']['current']
 379             if unit_status != 'idle':
 380                 return False
 381         return True
 382
 383     async def reset(self, force=False):
 384         """Reset the model to a clean state.
 385
 386         :param bool force: Force-terminate machines.
 387
 388         This returns only after the model has reached a clean state. "Clean"
 389         means no applications or machines exist in the model.
 390
 391         """
 392         log.debug('Resetting model')
 393         for app in self.applications.values():
 394             await app.destroy()
 395         for machine in self.machines.values():
 396             await machine.destroy(force=force)
 397         await self.block_until(
 398             lambda: len(self.machines) == 0
 399         )
 400
 401     async def block_until(self, *conditions, timeout=None):
 402         """Return only after all conditions are true.
 403
 404         """
 405         async def _block():
 406             while not all(c() for c in conditions):
 407                 await asyncio.sleep(0)
 408         await asyncio.wait_for(_block(), timeout)
 409
 410     @property
 411     def applications(self):
 412         """Return a map of application-name:Application for all applications
 413         currently in the model.
 414
 415         """
 416         return self.state.applications
 417
 418     @property
 419     def machines(self):
 420         """Return a map of machine-id:Machine for all machines currently in
 421         the model.
 422
 423         """
 424         return self.state.machines
 425
 426     @property
 427     def units(self):
 428         """Return a map of unit-id:Unit for all units currently in
 429         the model.
 430
 431         """
 432         return self.state.units
 433
 434     def add_observer(
 435             self, callable_, entity_type=None, action=None, entity_id=None,
 436             predicate=None):
 437         """Register an "on-model-change" callback
 438
 439         Once the model is connected, ``callable_``
 440         will be called each time the model changes. callable_ should
 441         be Awaitable and accept the following positional arguments:
 442
 443             delta - An instance of :class:`juju.delta.EntityDelta`
 444                 containing the raw delta data recv'd from the Juju
 445                 websocket.
 446
 447             old_obj - If the delta modifies an existing object in the model,
 448                 old_obj will be a copy of that object, as it was before the
 449                 delta was applied. Will be None if the delta creates a new
 450                 entity in the model.
 451
 452             new_obj - A copy of the new or updated object, after the delta
 453                 is applied. Will be None if the delta removes an entity
 454                 from the model.
 455
 456             model - The :class:`Model` itself.
 457
 458         Events for which ``callable_`` is called can be specified by passing
 459         entity_type, action, and/or id_ filter criteria, e.g.:
 460
 461             add_observer(
 462                 myfunc, entity_type='application', action='add', id_='ubuntu')
 463
 464         For more complex filtering conditions, pass a predicate function. It
 465         will be called with a delta as its only argument. If the predicate
 466         function returns True, the callable_ will be called.
 467
 468         """
 469         observer = _Observer(
 470             callable_, entity_type, action, entity_id, predicate)
 471         self.observers[observer] = callable_
 472
 473     def _watch(self):
 474         """Start an asynchronous watch against this model.
 475
 476         See :meth:`add_observer` to register an onchange callback.
 477
 478         """
 479         async def _start_watch():
 480             self._watch_shutdown.clear()
 481             try:
 482                 allwatcher = watcher.AllWatcher()
 483                 self._watch_conn = await self.connection.clone()
 484                 allwatcher.connect(self._watch_conn)
 485                 while True:
 486                     results = await allwatcher.Next()
 487                     for delta in results.deltas:
 488                         delta = get_entity_delta(delta)
 489                         old_obj, new_obj = self.state.apply_delta(delta)
 490                         # XXX: Might not want to shield at this level
 491                         # We are shielding because when the watcher is
 492                         # canceled (on disconnect()), we don't want all of
 493                         # its children (every observer callback) to be
 494                         # canceled with it. So we shield them. But this means
 495                         # they can *never* be canceled.
 496                         await asyncio.shield(
 497                             self._notify_observers(delta, old_obj, new_obj))
 498                     self._watch_received.set()
 499             except CancelledError:
 500                 log.debug('Closing watcher connection')
 501                 await self._watch_conn.close()
 502                 self._watch_shutdown.set()
 503                 self._watch_conn = None
 504
 505         log.debug('Starting watcher task')
 506         self._watcher_task = self.loop.create_task(_start_watch())
 507
 508     def _stop_watching(self):
 509         """Stop the asynchronous watch against this model.
 510
 511         """
 512         log.debug('Stopping watcher task')
 513         if self._watcher_task:
 514             self._watcher_task.cancel()
 515
 516     async def _notify_observers(self, delta, old_obj, new_obj):
 517         """Call observing callbacks, notifying them of a change in model state
 518
 519         :param delta: The raw change from the watcher
 520             (:class:`juju.client.overrides.Delta`)
 521         :param old_obj: The object in the model that this delta updates.
 522             May be None.
 523         :param new_obj: The object in the model that is created or updated
 524             by applying this delta.
 525
 526         """
 527         if new_obj and not old_obj:
 528             delta.type = 'add'
 529
 530         log.debug(
 531             'Model changed: %s %s %s',
 532             delta.entity, delta.type, delta.get_id())
 533
 534         for o in self.observers:
 535             if o.cares_about(delta):
 536                 asyncio.ensure_future(o(delta, old_obj, new_obj, self))
 537
 538     async def _wait_for_new(self, entity_type, entity_id, predicate=None):
 539         """Wait for a new object to appear in the Model and return it.
 540
 541         Waits for an object of type ``entity_type`` with id ``entity_id``.
 542
 543         This coroutine blocks until the new object appears in the model.
 544
 545         """
 546         entity_added = asyncio.Queue(loop=self.loop)
 547
 548         async def callback(delta, old, new, model):
 549             await entity_added.put(delta.get_id())
 550
 551         self.add_observer(callback, entity_type, 'add', entity_id, predicate)
 552         entity_id = await entity_added.get()
 553         return self.state._live_entity_map(entity_type)[entity_id]
 554
 555     def add_machine(
 556             self, spec=None, constraints=None, disks=None, series=None,
 557             count=1):
 558         """Start a new, empty machine and optionally a container, or add a
 559         container to a machine.
 560
 561         :param str spec: Machine specification
 562             Examples::
 563
 564                 (None) - starts a new machine
 565                 'lxc' - starts a new machine with on lxc container
 566                 'lxc:4' - starts a new lxc container on machine 4
 567                 'ssh:user@10.10.0.3' - manually provisions a machine with ssh
 568                 'zone=us-east-1a' - starts a machine in zone us-east-1s on AWS
 569                 'maas2.name' - acquire machine maas2.name on MAAS
 570         :param constraints: Machine constraints
 571         :type constraints: :class:`juju.Constraints`
 572         :param list disks: List of disk :class:`constraints <juju.Constraints>`
 573         :param str series: Series
 574         :param int count: Number of machines to deploy
 575
 576         Supported container types are: lxc, lxd, kvm
 577
 578         When deploying a container to an existing machine, constraints cannot
 579         be used.
 580
 581         """
 582         pass
 583     add_machines = add_machine
 584
 585     async def add_relation(self, relation1, relation2):
 586         """Add a relation between two applications.
 587
 588         :param str relation1: '<application>[:<relation_name>]'
 589         :param str relation2: '<application>[:<relation_name>]'
 590
 591         """
 592         app_facade = client.ApplicationFacade()
 593         app_facade.connect(self.connection)
 594
 595         log.debug(
 596             'Adding relation %s <-> %s', relation1, relation2)
 597
 598         try:
 599             result = await app_facade.AddRelation([relation1, relation2])
 600         except JujuAPIError as e:
 601             if 'relation already exists' not in e.message:
 602                 raise
 603             log.debug(
 604                 'Relation %s <-> %s already exists', relation1, relation2)
 605             # TODO: if relation already exists we should return the
 606             # Relation ModelEntity here
 607             return None
 608
 609         def predicate(delta):
 610             endpoints = {}
 611             for endpoint in delta.data['endpoints']:
 612                 endpoints[endpoint['application-name']] = endpoint['relation']
 613             return endpoints == result.endpoints
 614
 615         return await self._wait_for_new('relation', None, predicate)
 616
 617     def add_space(self, name, *cidrs):
 618         """Add a new network space.
 619
 620         Adds a new space with the given name and associates the given
 621         (optional) list of existing subnet CIDRs with it.
 622
 623         :param str name: Name of the space
 624         :param \*cidrs: Optional list of existing subnet CIDRs
 625
 626         """
 627         pass
 628
 629     def add_ssh_key(self, key):
 630         """Add a public SSH key to this model.
 631
 632         :param str key: The public ssh key
 633
 634         """
 635         pass
 636     add_ssh_keys = add_ssh_key
 637
 638     def add_subnet(self, cidr_or_id, space, *zones):
 639         """Add an existing subnet to this model.
 640
 641         :param str cidr_or_id: CIDR or provider ID of the existing subnet
 642         :param str space: Network space with which to associate
 643         :param str \*zones: Zone(s) in which the subnet resides
 644
 645         """
 646         pass
 647
 648     def get_backups(self):
 649         """Retrieve metadata for backups in this model.
 650
 651         """
 652         pass
 653
 654     def block(self, *commands):
 655         """Add a new block to this model.
 656
 657         :param str \*commands: The commands to block. Valid values are
 658             'all-changes', 'destroy-model', 'remove-object'
 659
 660         """
 661         pass
 662
 663     def get_blocks(self):
 664         """List blocks for this model.
 665
 666         """
 667         pass
 668
 669     def get_cached_images(self, arch=None, kind=None, series=None):
 670         """Return a list of cached OS images.
 671
 672         :param str arch: Filter by image architecture
 673         :param str kind: Filter by image kind, e.g. 'lxd'
 674         :param str series: Filter by image series, e.g. 'xenial'
 675
 676         """
 677         pass
 678
 679     def create_backup(self, note=None, no_download=False):
 680         """Create a backup of this model.
 681
 682         :param str note: A note to store with the backup
 683         :param bool no_download: Do not download the backup archive
 684         :return str: Path to downloaded archive
 685
 686         """
 687         pass
 688
 689     def create_storage_pool(self, name, provider_type, **pool_config):
 690         """Create or define a storage pool.
 691
 692         :param str name: Name to give the storage pool
 693         :param str provider_type: Pool provider type
 694         :param \*\*pool_config: key/value pool configuration pairs
 695
 696         """
 697         pass
 698
 699     def debug_log(
 700             self, no_tail=False, exclude_module=None, include_module=None,
 701             include=None, level=None, limit=0, lines=10, replay=False,
 702             exclude=None):
 703         """Get log messages for this model.
 704
 705         :param bool no_tail: Stop after returning existing log messages
 706         :param list exclude_module: Do not show log messages for these logging
 707             modules
 708         :param list include_module: Only show log messages for these logging
 709             modules
 710         :param list include: Only show log messages for these entities
 711         :param str level: Log level to show, valid options are 'TRACE',
 712             'DEBUG', 'INFO', 'WARNING', 'ERROR,
 713         :param int limit: Return this many of the most recent (possibly
 714             filtered) lines are shown
 715         :param int lines: Yield this many of the most recent lines, and keep
 716             yielding
 717         :param bool replay: Yield the entire log, and keep yielding
 718         :param list exclude: Do not show log messages for these entities
 719
 720         """
 721         pass
 722
 723     async def deploy(
 724             self, entity_url, service_name=None, bind=None, budget=None,
 725             channel=None, config=None, constraints=None, force=False,
 726             num_units=1, plan=None, resources=None, series=None, storage=None,
 727             to=None):
 728         """Deploy a new service or bundle.
 729
 730         :param str entity_url: Charm or bundle url
 731         :param str service_name: Name to give the service
 732         :param dict bind: <charm endpoint>:<network space> pairs
 733         :param dict budget: <budget name>:<limit> pairs
 734         :param str channel: Charm store channel from which to retrieve
 735             the charm or bundle, e.g. 'development'
 736         :param dict config: Charm configuration dictionary
 737         :param constraints: Service constraints
 738         :type constraints: :class:`juju.Constraints`
 739         :param bool force: Allow charm to be deployed to a machine running
 740             an unsupported series
 741         :param int num_units: Number of units to deploy
 742         :param str plan: Plan under which to deploy charm
 743         :param dict resources: <resource name>:<file path> pairs
 744         :param str series: Series on which to deploy
 745         :param dict storage: Storage constraints TODO how do these look?
 746         :param str to: Placement directive, e.g.::
 747
 748             '23' - machine 23
 749             'lxc:7' - new lxc container on machine 7
 750             '24/lxc/3' - lxc container 3 or machine 24
 751
 752             If None, a new machine is provisioned.
 753
 754
 755         TODO::
 756
 757             - service_name is required; fill this in automatically if not
 758               provided by caller
 759             - series is required; how do we pick a default?
 760
 761         """
 762         if constraints:
 763             constraints = client.Value(**constraints)
 764
 765         if to:
 766             placement = [
 767                 client.Placement(**p) for p in to
 768             ]
 769         else:
 770             placement = []
 771
 772         if storage:
 773             storage = {
 774                 k: client.Constraints(**v)
 775                 for k, v in storage.items()
 776             }
 777
 778         entity_id = await self.charmstore.entityId(entity_url)
 779
 780         app_facade = client.ApplicationFacade()
 781         client_facade = client.ClientFacade()
 782         app_facade.connect(self.connection)
 783         client_facade.connect(self.connection)
 784
 785         if 'bundle/' in entity_id:
 786             handler = BundleHandler(self)
 787             await handler.fetch_plan(entity_id)
 788             await handler.execute_plan()
 789             extant_apps = {app for app in self.applications}
 790             pending_apps = set(handler.applications) - extant_apps
 791             if pending_apps:
 792                 # new apps will usually be in the model by now, but if some
 793                 # haven't made it yet we'll need to wait on them to be added
 794                 await asyncio.wait([self._wait_for_new('application', app_name)
 795                                     for app_name in pending_apps])
 796             return [app for name, app in self.applications.items()
 797                     if name in handler.applications]
 798         else:
 799             log.debug(
 800                 'Deploying %s', entity_id)
 801
 802             await client_facade.AddCharm(channel, entity_id)
 803             app = client.ApplicationDeploy(
 804                 application=service_name,
 805                 channel=channel,
 806                 charm_url=entity_id,
 807                 config=config,
 808                 constraints=constraints,
 809                 endpoint_bindings=bind,
 810                 num_units=num_units,
 811                 placement=placement,
 812                 resources=resources,
 813                 series=series,
 814                 storage=storage,
 815             )
 816
 817             await app_facade.Deploy([app])
 818             return [await self._wait_for_new('application', service_name)]
 819
 820     def destroy(self):
 821         """Terminate all machines and resources for this model.
 822
 823         """
 824         pass
 825
 826     async def destroy_unit(self, *unit_names):
 827         """Destroy units by name.
 828
 829         """
 830         app_facade = client.ApplicationFacade()
 831         app_facade.connect(self.connection)
 832
 833         log.debug(
 834             'Destroying unit%s %s',
 835             's' if len(unit_names) == 1 else '',
 836             ' '.join(unit_names))
 837
 838         return await app_facade.Destroy(self.name)
 839     destroy_units = destroy_unit
 840
 841     def get_backup(self, archive_id):
 842         """Download a backup archive file.
 843
 844         :param str archive_id: The id of the archive to download
 845         :return str: Path to the archive file
 846
 847         """
 848         pass
 849
 850     def enable_ha(
 851             self, num_controllers=0, constraints=None, series=None, to=None):
 852         """Ensure sufficient controllers exist to provide redundancy.
 853
 854         :param int num_controllers: Number of controllers to make available
 855         :param constraints: Constraints to apply to the controller machines
 856         :type constraints: :class:`juju.Constraints`
 857         :param str series: Series of the controller machines
 858         :param list to: Placement directives for controller machines, e.g.::
 859
 860             '23' - machine 23
 861             'lxc:7' - new lxc container on machine 7
 862             '24/lxc/3' - lxc container 3 or machine 24
 863
 864             If None, a new machine is provisioned.
 865
 866         """
 867         pass
 868
 869     def get_config(self):
 870         """Return the configuration settings for this model.
 871
 872         """
 873         pass
 874
 875     def get_constraints(self):
 876         """Return the machine constraints for this model.
 877
 878         """
 879         pass
 880
 881     def grant(self, username, acl='read'):
 882         """Grant a user access to this model.
 883
 884         :param str username: Username
 885         :param str acl: Access control ('read' or 'write')
 886
 887         """
 888         pass
 889
 890     def import_ssh_key(self, identity):
 891         """Add a public SSH key from a trusted indentity source to this model.
 892
 893         :param str identity: User identity in the form <lp|gh>:<username>
 894
 895         """
 896         pass
 897     import_ssh_keys = import_ssh_key
 898
 899     def get_machines(self, machine, utc=False):
 900         """Return list of machines in this model.
 901
 902         :param str machine: Machine id, e.g. '0'
 903         :param bool utc: Display time as UTC in RFC3339 format
 904
 905         """
 906         pass
 907
 908     def get_shares(self):
 909         """Return list of all users with access to this model.
 910
 911         """
 912         pass
 913
 914     def get_spaces(self):
 915         """Return list of all known spaces, including associated subnets.
 916
 917         """
 918         pass
 919
 920     def get_ssh_key(self):
 921         """Return known SSH keys for this model.
 922
 923         """
 924         pass
 925     get_ssh_keys = get_ssh_key
 926
 927     def get_storage(self, filesystem=False, volume=False):
 928         """Return details of storage instances.
 929
 930         :param bool filesystem: Include filesystem storage
 931         :param bool volume: Include volume storage
 932
 933         """
 934         pass
 935
 936     def get_storage_pools(self, names=None, providers=None):
 937         """Return list of storage pools.
 938
 939         :param list names: Only include pools with these names
 940         :param list providers: Only include pools for these providers
 941
 942         """
 943         pass
 944
 945     def get_subnets(self, space=None, zone=None):
 946         """Return list of known subnets.
 947
 948         :param str space: Only include subnets in this space
 949         :param str zone: Only include subnets in this zone
 950
 951         """
 952         pass
 953
 954     def remove_blocks(self):
 955         """Remove all blocks from this model.
 956
 957         """
 958         pass
 959
 960     def remove_backup(self, backup_id):
 961         """Delete a backup.
 962
 963         :param str backup_id: The id of the backup to remove
 964
 965         """
 966         pass
 967
 968     def remove_cached_images(self, arch=None, kind=None, series=None):
 969         """Remove cached OS images.
 970
 971         :param str arch: Architecture of the images to remove
 972         :param str kind: Image kind to remove, e.g. 'lxd'
 973         :param str series: Image series to remove, e.g. 'xenial'
 974
 975         """
 976         pass
 977
 978     def remove_machine(self, *machine_ids):
 979         """Remove a machine from this model.
 980
 981         :param str \*machine_ids: Ids of the machines to remove
 982
 983         """
 984         pass
 985     remove_machines = remove_machine
 986
 987     def remove_ssh_key(self, *keys):
 988         """Remove a public SSH key(s) from this model.
 989
 990         :param str \*keys: Keys to remove
 991
 992         """
 993         pass
 994     remove_ssh_keys = remove_ssh_key
 995
 996     def restore_backup(
 997             self, bootstrap=False, constraints=None, archive=None,
 998             backup_id=None, upload_tools=False):
 999         """Restore a backup archive to a new controller.
1000
1001         :param bool bootstrap: Bootstrap a new state machine
1002         :param constraints: Model constraints
1003         :type constraints: :class:`juju.Constraints`
1004         :param str archive: Path to backup archive to restore
1005         :param str backup_id: Id of backup to restore
1006         :param bool upload_tools: Upload tools if bootstrapping a new machine
1007
1008         """
1009         pass
1010
1011     def retry_provisioning(self):
1012         """Retry provisioning for failed machines.
1013
1014         """
1015         pass
1016
1017     def revoke(self, username, acl='read'):
1018         """Revoke a user's access to this model.
1019
1020         :param str username: Username to revoke
1021         :param str acl: Access control ('read' or 'write')
1022
1023         """
1024         pass
1025
1026     def run(self, command, timeout=None):
1027         """Run command on all machines in this model.
1028
1029         :param str command: The command to run
1030         :param int timeout: Time to wait before command is considered failed
1031
1032         """
1033         pass
1034
1035     def set_config(self, **config):
1036         """Set configuration keys on this model.
1037
1038         :param \*\*config: Config key/values
1039
1040         """
1041         pass
1042
1043     def set_constraints(self, constraints):
1044         """Set machine constraints on this model.
1045
1046         :param :class:`juju.Constraints` constraints: Machine constraints
1047
1048         """
1049         pass
1050
1051     def get_action_output(self, action_uuid, wait=-1):
1052         """Get the results of an action by ID.
1053
1054         :param str action_uuid: Id of the action
1055         :param int wait: Time in seconds to wait for action to complete
1056
1057         """
1058         pass
1059
1060     def get_action_status(self, uuid_or_prefix=None, name=None):
1061         """Get the status of all actions, filtered by ID, ID prefix, or action name.
1062
1063         :param str uuid_or_prefix: Filter by action uuid or prefix
1064         :param str name: Filter by action name
1065
1066         """
1067         pass
1068
1069     def get_budget(self, budget_name):
1070         """Get budget usage info.
1071
1072         :param str budget_name: Name of budget
1073
1074         """
1075         pass
1076
1077     def get_status(self, filter_=None, utc=False):
1078         """Return the status of the model.
1079
1080         :param str filter_: Service or unit name or wildcard ('*')
1081         :param bool utc: Display time as UTC in RFC3339 format
1082
1083         """
1084         pass
1085     status = get_status
1086
1087     def sync_tools(
1088             self, all_=False, destination=None, dry_run=False, public=False,
1089             source=None, stream=None, version=None):
1090         """Copy Juju tools into this model.
1091
1092         :param bool all_: Copy all versions, not just the latest
1093         :param str destination: Path to local destination directory
1094         :param bool dry_run: Don't do the actual copy
1095         :param bool public: Tools are for a public cloud, so generate mirrors
1096             information
1097         :param str source: Path to local source directory
1098         :param str stream: Simplestreams stream for which to sync metadata
1099         :param str version: Copy a specific major.minor version
1100
1101         """
1102         pass
1103
1104     def unblock(self, *commands):
1105         """Unblock an operation that would alter this model.
1106
1107         :param str \*commands: The commands to unblock. Valid values are
1108             'all-changes', 'destroy-model', 'remove-object'
1109
1110         """
1111         pass
1112
1113     def unset_config(self, *keys):
1114         """Unset configuration on this model.
1115
1116         :param str \*keys: The keys to unset
1117
1118         """
1119         pass
1120
1121     def upgrade_gui(self):
1122         """Upgrade the Juju GUI for this model.
1123
1124         """
1125         pass
1126
1127     def upgrade_juju(
1128             self, dry_run=False, reset_previous_upgrade=False,
1129             upload_tools=False, version=None):
1130         """Upgrade Juju on all machines in a model.
1131
1132         :param bool dry_run: Don't do the actual upgrade
1133         :param bool reset_previous_upgrade: Clear the previous (incomplete)
1134             upgrade status
1135         :param bool upload_tools: Upload local version of tools
1136         :param str version: Upgrade to a specific version
1137
1138         """
1139         pass
1140
1141     def upload_backup(self, archive_path):
1142         """Store a backup archive remotely in Juju.
1143
1144         :param str archive_path: Path to local archive
1145
1146         """
1147         pass
1148
1149     @property
1150     def charmstore(self):
1151         return self._charmstore
1152
1153
1154 class BundleHandler(object):
1155     """
1156     Handle bundles by using the API to translate bundle YAML into a plan of
1157     steps and then dispatching each of those using the API.
1158     """
1159     def __init__(self, model):
1160         self.model = model
1161         self.charmstore = model.charmstore
1162         self.plan = []
1163         self.references = {}
1164         self._units_by_app = {}
1165         for unit_name, unit in model.units.items():
1166             app_units = self._units_by_app.setdefault(unit.application, [])
1167             app_units.append(unit_name)
1168         self.client_facade = client.ClientFacade()
1169         self.client_facade.connect(model.connection)
1170         self.app_facade = client.ApplicationFacade()
1171         self.app_facade.connect(model.connection)
1172         self.ann_facade = client.AnnotationsFacade()
1173         self.ann_facade.connect(model.connection)
1174
1175     async def fetch_plan(self, entity_id):
1176         bundle_yaml = await self.charmstore.files(entity_id,
1177                                                   filename='bundle.yaml',
1178                                                   read_file=True)
1179         self.bundle = yaml.safe_load(bundle_yaml)
1180         self.plan = await self.client_facade.GetBundleChanges(bundle_yaml)
1181
1182     async def execute_plan(self):
1183         for step in self.plan.changes:
1184             method = getattr(self, step.method)
1185             result = await method(*step.args)
1186             self.references[step.id_] = result
1187
1188     @property
1189     def applications(self):
1190         return list(self.bundle['services'].keys())
1191
1192     def resolve(self, reference):
1193         if reference and reference.startswith('$'):
1194             reference = self.references[reference[1:]]
1195         return reference
1196
1197     async def addCharm(self, charm, series):
1198         """
1199         :param charm string:
1200             Charm holds the URL of the charm to be added.
1201
1202         :param series string:
1203             Series holds the series of the charm to be added
1204             if the charm default is not sufficient.
1205         """
1206         entity_id = await self.charmstore.entityId(charm)
1207         log.debug('Adding %s', entity_id)
1208         await self.client_facade.AddCharm(None, entity_id)
1209         return entity_id
1210
1211     async def addMachines(self, series, constraints, container_type,
1212                           parent_id):
1213         """
1214         :param series string:
1215             Series holds the optional machine OS series.
1216
1217         :param constraints string:
1218             Constraints holds the optional machine constraints.
1219
1220         :param Container_type string:
1221             ContainerType optionally holds the type of the container (for
1222             instance ""lxc" or kvm"). It is not specified for top level
1223             machines.
1224
1225         :param parent_id string:
1226             ParentId optionally holds a placeholder pointing to another machine
1227             change or to a unit change. This value is only specified in the
1228             case this machine is a container, in which case also ContainerType
1229             is set.
1230         """
1231         params = client.AddMachineParams(
1232             series=series,
1233             constraints=constraints,
1234             container_type=container_type,
1235             parent_id=self.resolve(parent_id),
1236         )
1237         results = await self.client_facade.AddMachines(params)
1238         log.debug('Added new machine %s', results[0].machine)
1239         return results[0].machine
1240
1241     async def addRelation(self, endpoint1, endpoint2):
1242         """
1243         :param endpoint1 string:
1244         :param endpoint2 string:
1245             Endpoint1 and Endpoint2 hold relation endpoints in the
1246             "application:interface" form, where the application is always a
1247             placeholder pointing to an application change, and the interface is
1248             optional. Examples are "$deploy-42:web" or just "$deploy-42".
1249         """
1250         endpoints = [endpoint1, endpoint2]
1251         # resolve indirect references
1252         for i in range(len(endpoints)):
1253             parts = endpoints[i].split(':')
1254             parts[0] = self.resolve(parts[0])
1255             endpoints[i] = ':'.join(parts)
1256
1257         log.info('Relating %s <-> %s', *endpoints)
1258         return await self.model.add_relation(*endpoints)
1259
1260     async def deploy(self, charm, series, application, options, constraints,
1261                      storage, endpoint_bindings, resources):
1262         """
1263         :param charm string:
1264             Charm holds the URL of the charm to be used to deploy this
1265             application.
1266
1267         :param series string:
1268             Series holds the series of the application to be deployed
1269             if the charm default is not sufficient.
1270
1271         :param application string:
1272             Application holds the application name.
1273
1274         :param options map[string]interface{}:
1275             Options holds application options.
1276
1277         :param constraints string:
1278             Constraints holds the optional application constraints.
1279
1280         :param storage map[string]string:
1281             Storage holds the optional storage constraints.
1282
1283         :param endpoint_bindings map[string]string:
1284             EndpointBindings holds the optional endpoint bindings
1285
1286         :param resources map[string]int:
1287             Resources identifies the revision to use for each resource
1288             of the application's charm.
1289         """
1290         # resolve indirect references
1291         charm = self.resolve(charm)
1292         # stringify all config values for API
1293         options = {k: str(v) for k, v in options.items()}
1294         # build param object
1295         app = client.ApplicationDeploy(
1296             charm_url=charm,
1297             series=series,
1298             application=application,
1299             config=options,
1300             constraints=constraints,
1301             storage=storage,
1302             endpoint_bindings=endpoint_bindings,
1303             resources=resources,
1304         )
1305         # do the do
1306         log.info('Deploying %s', charm)
1307         await self.app_facade.Deploy([app])
1308         return application
1309
1310     async def addUnit(self, application, to):
1311         """
1312         :param application string:
1313             Application holds the application placeholder name for which a unit
1314             is added.
1315
1316         :param to string:
1317             To holds the optional location where to add the unit, as a
1318             placeholder pointing to another unit change or to a machine change.
1319         """
1320         application = self.resolve(application)
1321         placement = self.resolve(to)
1322         if self._units_by_app.get(application):
1323             # enough units for this application already exist;
1324             # claim one, and carry on
1325             # NB: this should probably honor placement, but the juju client
1326             # doesn't, so we're not bothering, either
1327             unit_name = self._units_by_app[application].pop()
1328             log.debug('Reusing unit %s for %s', unit_name, application)
1329             return self.model.units[unit_name]
1330
1331         log.debug('Adding new unit for %s%s', application,
1332                   ' to %s' % placement if placement else '')
1333         return await self.model.applications[application].add_unit(
1334             count=1,
1335             to=placement,
1336         )
1337
1338     async def expose(self, application):
1339         """
1340         :param application string:
1341             Application holds the placeholder name of the application that must
1342             be exposed.
1343         """
1344         application = self.resolve(application)
1345         log.info('Exposing %s', application)
1346         return await self.model.applications[application].expose()
1347
1348     async def setAnnotations(self, id_, entity_type, annotations):
1349         """
1350         :param id_ string:
1351             Id is the placeholder for the application or machine change
1352             corresponding to the entity to be annotated.
1353
1354         :param entity_type EntityType:
1355             EntityType holds the type of the entity, "application" or
1356             "machine".
1357
1358         :param annotations map[string]string:
1359             Annotations holds the annotations as key/value pairs.
1360         """
1361         entity_id = self.resolve(id_)
1362         try:
1363             entity = self.model.state.get_entity(entity_type, entity_id)
1364         except KeyError:
1365             entity = await self.model._wait_for_new(entity_type, entity_id)
1366         return await entity.set_annotations(annotations)
1367
1368
1369 class CharmStore(object):
1370     """
1371     Async wrapper around theblues.charmstore.CharmStore
1372     """
1373     def __init__(self, loop):
1374         self.loop = loop
1375         self._cs = charmstore.CharmStore()
1376
1377     def __getattr__(self, name):
1378         """
1379         Wrap method calls in coroutines that use run_in_executor to make them
1380         async.
1381         """
1382         attr = getattr(self._cs, name)
1383         if not callable(attr):
1384             wrapper = partial(getattr, self._cs, name)
1385             setattr(self, name, wrapper)
1386         else:
1387             async def coro(*args, **kwargs):
1388                 method = partial(attr, *args, **kwargs)
1389                 return await self.loop.run_in_executor(None, method)
1390             setattr(self, name, coro)
1391             wrapper = coro
1392         return wrapper