n2vc/vnf.py

   1 import asyncio
   2 import logging
   3 import os
   4 import os.path
   5 import re
   6 import shlex
   7 import ssl
   8 import subprocess
   9 import sys
  10 # import time
  11
  12 # FIXME: this should load the juju inside or modules without having to
  13 # explicitly install it. Check why it's not working.
  14 # Load our subtree of the juju library
  15 path = os.path.abspath(os.path.join(os.path.dirname(__file__), '..'))
  16 path = os.path.join(path, "modules/libjuju/")
  17 if path not in sys.path:
  18     sys.path.insert(1, path)
  19
  20 from juju.controller import Controller
  21 from juju.model import ModelObserver
  22 from juju.errors import JujuAPIError, JujuError
  23
  24 # We might need this to connect to the websocket securely, but test and verify.
  25 try:
  26     ssl._create_default_https_context = ssl._create_unverified_context
  27 except AttributeError:
  28     # Legacy Python doesn't verify by default (see pep-0476)
  29     #   https://www.python.org/dev/peps/pep-0476/
  30     pass
  31
  32
  33 # Custom exceptions
  34 class JujuCharmNotFound(Exception):
  35     """The Charm can't be found or is not readable."""
  36
  37
  38 class JujuApplicationExists(Exception):
  39     """The Application already exists."""
  40
  41
  42 class N2VCPrimitiveExecutionFailed(Exception):
  43     """Something failed while attempting to execute a primitive."""
  44
  45
  46 class NetworkServiceDoesNotExist(Exception):
  47     """The Network Service being acted against does not exist."""
  48
  49
  50 # Quiet the debug logging
  51 logging.getLogger('websockets.protocol').setLevel(logging.INFO)
  52 logging.getLogger('juju.client.connection').setLevel(logging.WARN)
  53 logging.getLogger('juju.model').setLevel(logging.WARN)
  54 logging.getLogger('juju.machine').setLevel(logging.WARN)
  55
  56
  57 class VCAMonitor(ModelObserver):
  58     """Monitor state changes within the Juju Model."""
  59     log = None
  60     ns_name = None
  61     applications = {}
  62
  63     def __init__(self, ns_name):
  64         self.log = logging.getLogger(__name__)
  65
  66         self.ns_name = ns_name
  67
  68     def AddApplication(self, application_name, callback, *callback_args):
  69         if application_name not in self.applications:
  70             self.applications[application_name] = {
  71                 'callback': callback,
  72                 'callback_args': callback_args
  73             }
  74
  75     def RemoveApplication(self, application_name):
  76         if application_name in self.applications:
  77             del self.applications[application_name]
  78
  79     async def on_change(self, delta, old, new, model):
  80         """React to changes in the Juju model."""
  81
  82         if delta.entity == "unit":
  83             # Ignore change events from other applications
  84             if delta.data['application'] not in self.applications.keys():
  85                 return
  86
  87             try:
  88
  89                 application_name = delta.data['application']
  90
  91                 callback = self.applications[application_name]['callback']
  92                 callback_args = \
  93                     self.applications[application_name]['callback_args']
  94
  95                 if old and new:
  96                     # Fire off a callback with the application state
  97                     if callback:
  98                         callback(
  99                             self.ns_name,
 100                             delta.data['application'],
 101                             new.workload_status,
 102                             new.workload_status_message,
 103                             *callback_args)
 104
 105                 if old and not new:
 106                     # This is a charm being removed
 107                     if callback:
 108                         callback(
 109                             self.ns_name,
 110                             delta.data['application'],
 111                             "removed",
 112                             "",
 113                             *callback_args)
 114             except Exception as e:
 115                 self.log.debug("[1] notify_callback exception: {}".format(e))
 116
 117         elif delta.entity == "action":
 118             # TODO: Decide how we want to notify the user of actions
 119
 120             # uuid = delta.data['id']     # The Action's unique id
 121             # msg = delta.data['message'] # The output of the action
 122             #
 123             # if delta.data['status'] == "pending":
 124             #     # The action is queued
 125             #     pass
 126             # elif delta.data['status'] == "completed""
 127             #     # The action was successful
 128             #     pass
 129             # elif delta.data['status'] == "failed":
 130             #     # The action failed.
 131             #     pass
 132
 133             pass
 134
 135 ########
 136 # TODO
 137 #
 138 # Create unique models per network service
 139 # Document all public functions
 140
 141
 142 class N2VC:
 143     def __init__(self,
 144                  log=None,
 145                  server='127.0.0.1',
 146                  port=17070,
 147                  user='admin',
 148                  secret=None,
 149                  artifacts=None,
 150                  loop=None,
 151                  ):
 152         """Initialize N2VC
 153
 154         :param vcaconfig dict A dictionary containing the VCA configuration
 155
 156         :param artifacts str The directory where charms required by a vnfd are
 157             stored.
 158
 159         :Example:
 160         n2vc = N2VC(vcaconfig={
 161             'secret': 'MzI3MDJhOTYxYmM0YzRjNTJiYmY1Yzdm',
 162             'user': 'admin',
 163             'ip-address': '10.44.127.137',
 164             'port': 17070,
 165             'artifacts': '/path/to/charms'
 166         })
 167         """
 168
 169         # Initialize instance-level variables
 170         self.api = None
 171         self.log = None
 172         self.controller = None
 173         self.connecting = False
 174         self.authenticated = False
 175
 176         # For debugging
 177         self.refcount = {
 178             'controller': 0,
 179             'model': 0,
 180         }
 181
 182         self.models = {}
 183
 184         # Model Observers
 185         self.monitors = {}
 186
 187         # VCA config
 188         self.hostname = ""
 189         self.port = 17070
 190         self.username = ""
 191         self.secret = ""
 192
 193         if log:
 194             self.log = log
 195         else:
 196             self.log = logging.getLogger(__name__)
 197
 198         # Quiet websocket traffic
 199         logging.getLogger('websockets.protocol').setLevel(logging.INFO)
 200         logging.getLogger('juju.client.connection').setLevel(logging.WARN)
 201         logging.getLogger('model').setLevel(logging.WARN)
 202         # logging.getLogger('websockets.protocol').setLevel(logging.DEBUG)
 203
 204         self.log.debug('JujuApi: instantiated')
 205
 206         self.server = server
 207         self.port = port
 208
 209         self.secret = secret
 210         if user.startswith('user-'):
 211             self.user = user
 212         else:
 213             self.user = 'user-{}'.format(user)
 214
 215         self.endpoint = '%s:%d' % (server, int(port))
 216
 217         self.artifacts = artifacts
 218
 219         self.loop = loop or asyncio.get_event_loop()
 220
 221     def __del__(self):
 222         """Close any open connections."""
 223         yield self.logout()
 224
 225     def notify_callback(self, model_name, application_name, status, message,
 226                         callback=None, *callback_args):
 227         try:
 228             if callback:
 229                 callback(
 230                     model_name,
 231                     application_name,
 232                     status, message,
 233                     *callback_args,
 234                 )
 235         except Exception as e:
 236             self.log.error("[0] notify_callback exception {}".format(e))
 237             raise e
 238         return True
 239
 240     # Public methods
 241     async def Relate(self, model_name, vnfd):
 242         """Create a relation between the charm-enabled VDUs in a VNF.
 243
 244         The Relation mapping has two parts: the id of the vdu owning the endpoint, and the name of the endpoint.
 245
 246         vdu:
 247             ...
 248             relation:
 249             -   provides: dataVM:db
 250                 requires: mgmtVM:app
 251
 252         This tells N2VC that the charm referred to by the dataVM vdu offers a relation named 'db', and the mgmtVM vdu has an 'app' endpoint that should be connected to a database.
 253
 254         :param str ns_name: The name of the network service.
 255         :param dict vnfd: The parsed yaml VNF descriptor.
 256         """
 257
 258         # Currently, the call to Relate() is made automatically after the
 259         # deployment of each charm; if the relation depends on a charm that
 260         # hasn't been deployed yet, the call will fail silently. This will
 261         # prevent an API breakage, with the intent of making this an explicitly
 262         # required call in a more object-oriented refactor of the N2VC API.
 263
 264         configs = []
 265         vnf_config = vnfd.get("vnf-configuration")
 266         if vnf_config:
 267             juju = vnf_config['juju']
 268             if juju:
 269                 configs.append(vnf_config)
 270
 271         for vdu in vnfd['vdu']:
 272             vdu_config = vdu.get('vdu-configuration')
 273             if vdu_config:
 274                 juju = vdu_config['juju']
 275                 if juju:
 276                     configs.append(vdu_config)
 277
 278         def _get_application_name(name):
 279             """Get the application name that's mapped to a vnf/vdu."""
 280             vnf_member_index = 0
 281             vnf_name = vnfd['name']
 282
 283             for vdu in vnfd.get('vdu'):
 284                 # Compare the named portion of the relation to the vdu's id
 285                 if vdu['id'] == name:
 286                     application_name = self.FormatApplicationName(
 287                         model_name,
 288                         vnf_name,
 289                         str(vnf_member_index),
 290                     )
 291                     return application_name
 292                 else:
 293                     vnf_member_index += 1
 294
 295             return None
 296
 297         # Loop through relations
 298         for cfg in configs:
 299             if 'juju' in cfg:
 300                 if 'relation' in juju:
 301                     for rel in juju['relation']:
 302                         try:
 303
 304                             # get the application name for the provides
 305                             (name, endpoint) = rel['provides'].split(':')
 306                             application_name = _get_application_name(name)
 307
 308                             provides = "{}:{}".format(
 309                                 application_name,
 310                                 endpoint
 311                             )
 312
 313                             # get the application name for thr requires
 314                             (name, endpoint) = rel['requires'].split(':')
 315                             application_name = _get_application_name(name)
 316
 317                             requires = "{}:{}".format(
 318                                 application_name,
 319                                 endpoint
 320                             )
 321                             self.log.debug("Relation: {} <-> {}".format(
 322                                 provides,
 323                                 requires
 324                             ))
 325                             await self.add_relation(
 326                                 model_name,
 327                                 provides,
 328                                 requires,
 329                             )
 330                         except Exception as e:
 331                             self.log.debug("Exception: {}".format(e))
 332
 333         return
 334
 335     async def DeployCharms(self, model_name, application_name, vnfd,
 336                            charm_path, params={}, machine_spec={},
 337                            callback=None, *callback_args):
 338         """Deploy one or more charms associated with a VNF.
 339
 340         Deploy the charm(s) referenced in a VNF Descriptor.
 341
 342         :param str model_name: The name or unique id of the network service.
 343         :param str application_name: The name of the application
 344         :param dict vnfd: The name of the application
 345         :param str charm_path: The path to the Juju charm
 346         :param dict params: A dictionary of runtime parameters
 347           Examples::
 348           {
 349             'rw_mgmt_ip': '1.2.3.4',
 350             # Pass the initial-config-primitives section of the vnf or vdu
 351             'initial-config-primitives': {...}
 352             'user_values': dictionary with the day-1 parameters provided at instantiation time. It will replace values
 353                 inside < >. rw_mgmt_ip will be included here also
 354           }
 355         :param dict machine_spec: A dictionary describing the machine to
 356         install to
 357           Examples::
 358           {
 359             'hostname': '1.2.3.4',
 360             'username': 'ubuntu',
 361           }
 362         :param obj callback: A callback function to receive status changes.
 363         :param tuple callback_args: A list of arguments to be passed to the
 364         callback
 365         """
 366
 367         ########################################################
 368         # Verify the path to the charm exists and is readable. #
 369         ########################################################
 370         if not os.path.exists(charm_path):
 371             self.log.debug("Charm path doesn't exist: {}".format(charm_path))
 372             self.notify_callback(
 373                 model_name,
 374                 application_name,
 375                 "failed",
 376                 callback,
 377                 *callback_args,
 378             )
 379             raise JujuCharmNotFound("No artifacts configured.")
 380
 381         ################################
 382         # Login to the Juju controller #
 383         ################################
 384         if not self.authenticated:
 385             self.log.debug("Authenticating with Juju")
 386             await self.login()
 387
 388         ##########################################
 389         # Get the model for this network service #
 390         ##########################################
 391         model = await self.get_model(model_name)
 392
 393         ########################################
 394         # Verify the application doesn't exist #
 395         ########################################
 396         app = await self.get_application(model, application_name)
 397         if app:
 398             raise JujuApplicationExists("Can't deploy application \"{}\" to model \"{}\" because it already exists.".format(application_name, model_name))
 399
 400         ################################################################
 401         # Register this application with the model-level event monitor #
 402         ################################################################
 403         if callback:
 404             self.monitors[model_name].AddApplication(
 405                 application_name,
 406                 callback,
 407                 *callback_args
 408             )
 409
 410         ########################################################
 411         # Check for specific machine placement (native charms) #
 412         ########################################################
 413         to = ""
 414         if machine_spec.keys():
 415             if all(k in machine_spec for k in ['host', 'user']):
 416                 # Enlist an existing machine as a Juju unit
 417                 machine = await model.add_machine(spec='ssh:{}@{}:{}'.format(
 418                     machine_spec['user'],
 419                     machine_spec['host'],
 420                     self.GetPrivateKeyPath(),
 421                 ))
 422                 to = machine.id
 423
 424         #######################################
 425         # Get the initial charm configuration #
 426         #######################################
 427
 428         rw_mgmt_ip = None
 429         if 'rw_mgmt_ip' in params:
 430             rw_mgmt_ip = params['rw_mgmt_ip']
 431
 432         if 'initial-config-primitive' not in params:
 433             params['initial-config-primitive'] = {}
 434
 435         initial_config = self._get_config_from_dict(
 436             params['initial-config-primitive'],
 437             {'<rw_mgmt_ip>': rw_mgmt_ip}
 438         )
 439
 440         self.log.debug("JujuApi: Deploying charm ({}/{}) from {}".format(
 441             model_name,
 442             application_name,
 443             charm_path,
 444             to=to,
 445         ))
 446
 447         ########################################################
 448         # Deploy the charm and apply the initial configuration #
 449         ########################################################
 450         app = await model.deploy(
 451             # We expect charm_path to be either the path to the charm on disk
 452             # or in the format of cs:series/name
 453             charm_path,
 454             # This is the formatted, unique name for this charm
 455             application_name=application_name,
 456             # Proxy charms should use the current LTS. This will need to be
 457             # changed for native charms.
 458             series='xenial',
 459             # Apply the initial 'config' primitive during deployment
 460             config=initial_config,
 461             # Where to deploy the charm to.
 462             to=to,
 463         )
 464
 465         # Map the vdu id<->app name,
 466         #
 467         await self.Relate(model_name, vnfd)
 468
 469         # #######################################
 470         # # Execute initial config primitive(s) #
 471         # #######################################
 472         uuids = await self.ExecuteInitialPrimitives(
 473             model_name,
 474             application_name,
 475             params,
 476         )
 477         return uuids
 478
 479         # primitives = {}
 480         #
 481         # # Build a sequential list of the primitives to execute
 482         # for primitive in params['initial-config-primitive']:
 483         #     try:
 484         #         if primitive['name'] == 'config':
 485         #             # This is applied when the Application is deployed
 486         #             pass
 487         #         else:
 488         #             seq = primitive['seq']
 489         #
 490         #             params = {}
 491         #             if 'parameter' in primitive:
 492         #                 params = primitive['parameter']
 493         #
 494         #             primitives[seq] = {
 495         #                 'name': primitive['name'],
 496         #                 'parameters': self._map_primitive_parameters(
 497         #                     params,
 498         #                     {'<rw_mgmt_ip>': rw_mgmt_ip}
 499         #                 ),
 500         #             }
 501         #
 502         #             for primitive in sorted(primitives):
 503         #                 await self.ExecutePrimitive(
 504         #                     model_name,
 505         #                     application_name,
 506         #                     primitives[primitive]['name'],
 507         #                     callback,
 508         #                     callback_args,
 509         #                     **primitives[primitive]['parameters'],
 510         #                 )
 511         #     except N2VCPrimitiveExecutionFailed as e:
 512         #         self.log.debug(
 513         #             "[N2VC] Exception executing primitive: {}".format(e)
 514         #         )
 515         #         raise
 516
 517     async def GetPrimitiveStatus(self, model_name, uuid):
 518         """Get the status of an executed Primitive.
 519
 520         The status of an executed Primitive will be one of three values:
 521         - completed
 522         - failed
 523         - running
 524         """
 525         status = None
 526         try:
 527             if not self.authenticated:
 528                 await self.login()
 529
 530             model = await self.get_model(model_name)
 531
 532             results = await model.get_action_status(uuid)
 533
 534             if uuid in results:
 535                 status = results[uuid]
 536
 537         except Exception as e:
 538             self.log.debug(
 539                 "Caught exception while getting primitive status: {}".format(e)
 540             )
 541             raise N2VCPrimitiveExecutionFailed(e)
 542
 543         return status
 544
 545     async def GetPrimitiveOutput(self, model_name, uuid):
 546         """Get the output of an executed Primitive.
 547
 548         Note: this only returns output for a successfully executed primitive.
 549         """
 550         results = None
 551         try:
 552             if not self.authenticated:
 553                 await self.login()
 554
 555             model = await self.get_model(model_name)
 556             results = await model.get_action_output(uuid, 60)
 557         except Exception as e:
 558             self.log.debug(
 559                 "Caught exception while getting primitive status: {}".format(e)
 560             )
 561             raise N2VCPrimitiveExecutionFailed(e)
 562
 563         return results
 564
 565     # async def ProvisionMachine(self, model_name, hostname, username):
 566     #     """Provision machine for usage with Juju.
 567     #
 568     #     Provisions a previously instantiated machine for use with Juju.
 569     #     """
 570     #     try:
 571     #         if not self.authenticated:
 572     #             await self.login()
 573     #
 574     #         # FIXME: This is hard-coded until model-per-ns is added
 575     #         model_name = 'default'
 576     #
 577     #         model = await self.get_model(model_name)
 578     #         model.add_machine(spec={})
 579     #
 580     #         machine = await model.add_machine(spec='ssh:{}@{}:{}'.format(
 581     #             "ubuntu",
 582     #             host['address'],
 583     #             private_key_path,
 584     #         ))
 585     #         return machine.id
 586     #
 587     #     except Exception as e:
 588     #         self.log.debug(
 589     #             "Caught exception while getting primitive status: {}".format(e)
 590     #         )
 591     #         raise N2VCPrimitiveExecutionFailed(e)
 592
 593     def GetPrivateKeyPath(self):
 594         homedir = os.environ['HOME']
 595         sshdir = "{}/.ssh".format(homedir)
 596         private_key_path = "{}/id_n2vc_rsa".format(sshdir)
 597         return private_key_path
 598
 599     async def GetPublicKey(self):
 600         """Get the N2VC SSH public key.abs
 601
 602         Returns the SSH public key, to be injected into virtual machines to
 603         be managed by the VCA.
 604
 605         The first time this is run, a ssh keypair will be created. The public
 606         key is injected into a VM so that we can provision the machine with
 607         Juju, after which Juju will communicate with the VM directly via the
 608         juju agent.
 609         """
 610         public_key = ""
 611
 612         # Find the path to where we expect our key to live.
 613         homedir = os.environ['HOME']
 614         sshdir = "{}/.ssh".format(homedir)
 615         if not os.path.exists(sshdir):
 616             os.mkdir(sshdir)
 617
 618         private_key_path = "{}/id_n2vc_rsa".format(sshdir)
 619         public_key_path = "{}.pub".format(private_key_path)
 620
 621         # If we don't have a key generated, generate it.
 622         if not os.path.exists(private_key_path):
 623             cmd = "ssh-keygen -t {} -b {} -N '' -f {}".format(
 624                 "rsa",
 625                 "4096",
 626                 private_key_path
 627             )
 628             subprocess.check_output(shlex.split(cmd))
 629
 630         # Read the public key
 631         with open(public_key_path, "r") as f:
 632             public_key = f.readline()
 633
 634         return public_key
 635
 636     async def ExecuteInitialPrimitives(self, model_name, application_name,
 637                                        params, callback=None, *callback_args):
 638         """Execute multiple primitives.
 639
 640         Execute multiple primitives as declared in initial-config-primitive.
 641         This is useful in cases where the primitives initially failed -- for
 642         example, if the charm is a proxy but the proxy hasn't been configured
 643         yet.
 644         """
 645         uuids = []
 646         primitives = {}
 647
 648         # Build a sequential list of the primitives to execute
 649         for primitive in params['initial-config-primitive']:
 650             try:
 651                 if primitive['name'] == 'config':
 652                     pass
 653                 else:
 654                     seq = primitive['seq']
 655
 656                     params_ = {}
 657                     if 'parameter' in primitive:
 658                         params_ = primitive['parameter']
 659
 660                     user_values = params.get("user_values", {})
 661                     if 'rw_mgmt_ip' not in user_values:
 662                         user_values['rw_mgmt_ip'] = None
 663                         # just for backward compatibility, because it will be provided always by modern version of LCM
 664
 665                     primitives[seq] = {
 666                         'name': primitive['name'],
 667                         'parameters': self._map_primitive_parameters(
 668                             params_,
 669                             user_values
 670                         ),
 671                     }
 672
 673                     for primitive in sorted(primitives):
 674                         uuids.append(
 675                             await self.ExecutePrimitive(
 676                                 model_name,
 677                                 application_name,
 678                                 primitives[primitive]['name'],
 679                                 callback,
 680                                 callback_args,
 681                                 **primitives[primitive]['parameters'],
 682                             )
 683                         )
 684             except N2VCPrimitiveExecutionFailed as e:
 685                 self.log.debug(
 686                     "[N2VC] Exception executing primitive: {}".format(e)
 687                 )
 688                 raise
 689         return uuids
 690
 691     async def ExecutePrimitive(self, model_name, application_name, primitive,
 692                                callback, *callback_args, **params):
 693         """Execute a primitive of a charm for Day 1 or Day 2 configuration.
 694
 695         Execute a primitive defined in the VNF descriptor.
 696
 697         :param str model_name: The name or unique id of the network service.
 698         :param str application_name: The name of the application
 699         :param str primitive: The name of the primitive to execute.
 700         :param obj callback: A callback function to receive status changes.
 701         :param tuple callback_args: A list of arguments to be passed to the
 702          callback function.
 703         :param dict params: A dictionary of key=value pairs representing the
 704          primitive's parameters
 705           Examples::
 706           {
 707             'rw_mgmt_ip': '1.2.3.4',
 708             # Pass the initial-config-primitives section of the vnf or vdu
 709             'initial-config-primitives': {...}
 710           }
 711         """
 712         self.log.debug("Executing primitive={} params={}".format(primitive, params))
 713         uuid = None
 714         try:
 715             if not self.authenticated:
 716                 await self.login()
 717
 718             model = await self.get_model(model_name)
 719
 720             if primitive == 'config':
 721                 # config is special, and expecting params to be a dictionary
 722                 await self.set_config(
 723                     model,
 724                     application_name,
 725                     params['params'],
 726                 )
 727             else:
 728                 app = await self.get_application(model, application_name)
 729                 if app:
 730                     # Run against the first (and probably only) unit in the app
 731                     unit = app.units[0]
 732                     if unit:
 733                         action = await unit.run_action(primitive, **params)
 734                         uuid = action.id
 735         except Exception as e:
 736             self.log.debug(
 737                 "Caught exception while executing primitive: {}".format(e)
 738             )
 739             raise N2VCPrimitiveExecutionFailed(e)
 740         return uuid
 741
 742     async def RemoveCharms(self, model_name, application_name, callback=None,
 743                            *callback_args):
 744         """Remove a charm from the VCA.
 745
 746         Remove a charm referenced in a VNF Descriptor.
 747
 748         :param str model_name: The name of the network service.
 749         :param str application_name: The name of the application
 750         :param obj callback: A callback function to receive status changes.
 751         :param tuple callback_args: A list of arguments to be passed to the
 752          callback function.
 753         """
 754         try:
 755             if not self.authenticated:
 756                 await self.login()
 757
 758             model = await self.get_model(model_name)
 759             app = await self.get_application(model, application_name)
 760             if app:
 761                 # Remove this application from event monitoring
 762                 self.monitors[model_name].RemoveApplication(application_name)
 763
 764                 # self.notify_callback(model_name, application_name, "removing", callback, *callback_args)
 765                 self.log.debug(
 766                     "Removing the application {}".format(application_name)
 767                 )
 768                 await app.remove()
 769
 770                 await self.disconnect_model(self.monitors[model_name])
 771
 772                 # Notify the callback that this charm has been removed.
 773                 self.notify_callback(
 774                     model_name,
 775                     application_name,
 776                     "removed",
 777                     callback,
 778                     *callback_args,
 779                 )
 780
 781         except Exception as e:
 782             print("Caught exception: {}".format(e))
 783             self.log.debug(e)
 784             raise e
 785
 786     async def CreateNetworkService(self, ns_uuid):
 787         """Create a new Juju model for the Network Service.
 788
 789         Creates a new Model in the Juju Controller.
 790
 791         :param str ns_uuid: A unique id representing an instaance of a
 792             Network Service.
 793
 794         :returns: True if the model was created. Raises JujuError on failure.
 795         """
 796         if not self.authenticated:
 797             await self.login()
 798
 799         models = await self.controller.list_models()
 800         if ns_uuid not in models:
 801             try:
 802                 self.models[ns_uuid] = await self.controller.add_model(
 803                     ns_uuid
 804                 )
 805             except JujuError as e:
 806                 if "already exists" not in e.message:
 807                     raise e
 808         return True
 809
 810     async def DestroyNetworkService(self, ns_uuid):
 811         """Destroy a Network Service.
 812
 813         Destroy the Network Service and any deployed charms.
 814
 815         :param ns_uuid The unique id of the Network Service
 816
 817         :returns: True if the model was created. Raises JujuError on failure.
 818         """
 819
 820         # Do not delete the default model. The default model was used by all
 821         # Network Services, prior to the implementation of a model per NS.
 822         if ns_uuid.lower() is "default":
 823             return False
 824
 825         if not self.authenticated:
 826             self.log.debug("Authenticating with Juju")
 827             await self.login()
 828
 829         # Disconnect from the Model
 830         if ns_uuid in self.models:
 831             await self.disconnect_model(self.models[ns_uuid])
 832
 833         try:
 834             await self.controller.destroy_models(ns_uuid)
 835         except JujuError as e:
 836             raise NetworkServiceDoesNotExist(
 837                 "The Network Service '{}' does not exist".format(ns_uuid)
 838             )
 839
 840         return True
 841
 842     async def GetMetrics(self, model_name, application_name):
 843         """Get the metrics collected by the VCA.
 844
 845         :param model_name The name or unique id of the network service
 846         :param application_name The name of the application
 847         """
 848         metrics = {}
 849         model = await self.get_model(model_name)
 850         app = await self.get_application(model, application_name)
 851         if app:
 852             metrics = await app.get_metrics()
 853
 854         return metrics
 855
 856     async def HasApplication(self, model_name, application_name):
 857         model = await self.get_model(model_name)
 858         app = await self.get_application(model, application_name)
 859         if app:
 860             return True
 861         return False
 862
 863     # Non-public methods
 864     async def add_relation(self, model_name, relation1, relation2):
 865         """
 866         Add a relation between two application endpoints.
 867
 868         :param str model_name: The name or unique id of the network service
 869         :param str relation1: '<application>[:<relation_name>]'
 870         :param str relation2: '<application>[:<relation_name>]'
 871         """
 872
 873         if not self.authenticated:
 874             await self.login()
 875
 876         m = await self.get_model(model_name)
 877         try:
 878             await m.add_relation(relation1, relation2)
 879         except JujuAPIError as e:
 880             # If one of the applications in the relationship doesn't exist,
 881             # or the relation has already been added, let the operation fail
 882             # silently.
 883             if 'not found' in e.message:
 884                 return
 885             if 'already exists' in e.message:
 886                 return
 887
 888             raise e
 889
 890     # async def apply_config(self, config, application):
 891     #     """Apply a configuration to the application."""
 892     #     print("JujuApi: Applying configuration to {}.".format(
 893     #         application
 894     #     ))
 895     #     return await self.set_config(application=application, config=config)
 896
 897     def _get_config_from_dict(self, config_primitive, values):
 898         """Transform the yang config primitive to dict.
 899
 900         Expected result:
 901
 902             config = {
 903                 'config':
 904             }
 905         """
 906         config = {}
 907         for primitive in config_primitive:
 908             if primitive['name'] == 'config':
 909                 # config = self._map_primitive_parameters()
 910                 for parameter in primitive['parameter']:
 911                     param = str(parameter['name'])
 912                     if parameter['value'] == "<rw_mgmt_ip>":
 913                         config[param] = str(values[parameter['value']])
 914                     else:
 915                         config[param] = str(parameter['value'])
 916
 917         return config
 918
 919     def _map_primitive_parameters(self, parameters, user_values):
 920         params = {}
 921         for parameter in parameters:
 922             param = str(parameter['name'])
 923             value = parameter.get('value')
 924
 925             # map parameters inside a < >; e.g. <rw_mgmt_ip>. with the provided user_values.
 926             # Must exist at user_values except if there is a default value
 927             if isinstance(value, str) and value.startswith("<") and value.endswith(">"):
 928                 if parameter['value'][1:-1] in user_values:
 929                     value = user_values[parameter['value'][1:-1]]
 930                 elif 'default-value' in parameter:
 931                     value = parameter['default-value']
 932                 else:
 933                     raise KeyError("parameter {}='{}' not supplied ".format(param, value))
 934
 935             # If there's no value, use the default-value (if set)
 936             if value is None and 'default-value' in parameter:
 937                 value = parameter['default-value']
 938
 939             # Typecast parameter value, if present
 940             paramtype = "string"
 941             try:
 942                 if 'data-type' in parameter:
 943                     paramtype = str(parameter['data-type']).lower()
 944
 945                     if paramtype == "integer":
 946                         value = int(value)
 947                     elif paramtype == "boolean":
 948                         value = bool(value)
 949                     else:
 950                         value = str(value)
 951                 else:
 952                     # If there's no data-type, assume the value is a string
 953                     value = str(value)
 954             except ValueError:
 955                 raise ValueError("parameter {}='{}' cannot be converted to type {}".format(param, value, paramtype))
 956
 957             params[param] = value
 958         return params
 959
 960     def _get_config_from_yang(self, config_primitive, values):
 961         """Transform the yang config primitive to dict."""
 962         config = {}
 963         for primitive in config_primitive.values():
 964             if primitive['name'] == 'config':
 965                 for parameter in primitive['parameter'].values():
 966                     param = str(parameter['name'])
 967                     if parameter['value'] == "<rw_mgmt_ip>":
 968                         config[param] = str(values[parameter['value']])
 969                     else:
 970                         config[param] = str(parameter['value'])
 971
 972         return config
 973
 974     def FormatApplicationName(self, *args):
 975         """
 976         Generate a Juju-compatible Application name
 977
 978         :param args tuple: Positional arguments to be used to construct the
 979         application name.
 980
 981         Limitations::
 982         - Only accepts characters a-z and non-consequitive dashes (-)
 983         - Application name should not exceed 50 characters
 984
 985         Examples::
 986
 987             FormatApplicationName("ping_pong_ns", "ping_vnf", "a")
 988         """
 989         appname = ""
 990         for c in "-".join(list(args)):
 991             if c.isdigit():
 992                 c = chr(97 + int(c))
 993             elif not c.isalpha():
 994                 c = "-"
 995             appname += c
 996         return re.sub('-+', '-', appname.lower())
 997
 998     # def format_application_name(self, nsd_name, vnfr_name, member_vnf_index=0):
 999     #     """Format the name of the application
1000     #
1001     #     Limitations:
1002     #     - Only accepts characters a-z and non-consequitive dashes (-)
1003     #     - Application name should not exceed 50 characters
1004     #     """
1005     #     name = "{}-{}-{}".format(nsd_name, vnfr_name, member_vnf_index)
1006     #     new_name = ''
1007     #     for c in name:
1008     #         if c.isdigit():
1009     #             c = chr(97 + int(c))
1010     #         elif not c.isalpha():
1011     #             c = "-"
1012     #         new_name += c
1013     #     return re.sub('\-+', '-', new_name.lower())
1014
1015     def format_model_name(self, name):
1016         """Format the name of model.
1017
1018         Model names may only contain lowercase letters, digits and hyphens
1019         """
1020
1021         return name.replace('_', '-').lower()
1022
1023     async def get_application(self, model, application):
1024         """Get the deployed application."""
1025         if not self.authenticated:
1026             await self.login()
1027
1028         app = None
1029         if application and model:
1030             if model.applications:
1031                 if application in model.applications:
1032                     app = model.applications[application]
1033
1034         return app
1035
1036     async def get_model(self, model_name):
1037         """Get a model from the Juju Controller.
1038
1039         Note: Model objects returned must call disconnected() before it goes
1040         out of scope."""
1041         if not self.authenticated:
1042             await self.login()
1043
1044         if model_name not in self.models:
1045             # Get the models in the controller
1046             models = await self.controller.list_models()
1047
1048             if model_name not in models:
1049                 try:
1050                     self.models[model_name] = await self.controller.add_model(
1051                         model_name
1052                     )
1053                 except JujuError as e:
1054                     if "already exists" not in e.message:
1055                         raise e
1056             else:
1057                 self.models[model_name] = await self.controller.get_model(
1058                     model_name
1059                 )
1060
1061             self.refcount['model'] += 1
1062
1063             # Create an observer for this model
1064             self.monitors[model_name] = VCAMonitor(model_name)
1065             self.models[model_name].add_observer(self.monitors[model_name])
1066
1067         return self.models[model_name]
1068
1069     async def login(self):
1070         """Login to the Juju controller."""
1071
1072         if self.authenticated:
1073             return
1074
1075         self.connecting = True
1076
1077         self.log.debug("JujuApi: Logging into controller")
1078
1079         cacert = None
1080         self.controller = Controller(loop=self.loop)
1081
1082         if self.secret:
1083             self.log.debug(
1084                 "Connecting to controller... ws://{}:{} as {}/{}".format(
1085                     self.endpoint,
1086                     self.port,
1087                     self.user,
1088                     self.secret,
1089                 )
1090             )
1091             await self.controller.connect(
1092                 endpoint=self.endpoint,
1093                 username=self.user,
1094                 password=self.secret,
1095                 cacert=cacert,
1096             )
1097             self.refcount['controller'] += 1
1098         else:
1099             # current_controller no longer exists
1100             # self.log.debug("Connecting to current controller...")
1101             # await self.controller.connect_current()
1102             # await self.controller.connect(
1103             #     endpoint=self.endpoint,
1104             #     username=self.user,
1105             #     cacert=cacert,
1106             # )
1107             self.log.fatal("VCA credentials not configured.")
1108
1109         self.authenticated = True
1110         self.log.debug("JujuApi: Logged into controller")
1111
1112     async def logout(self):
1113         """Logout of the Juju controller."""
1114         if not self.authenticated:
1115             return False
1116
1117         try:
1118             for model in self.models:
1119                 await self.disconnect_model(model)
1120
1121             if self.controller:
1122                 self.log.debug("Disconnecting controller {}".format(
1123                     self.controller
1124                 ))
1125                 await self.controller.disconnect()
1126                 self.refcount['controller'] -= 1
1127                 self.controller = None
1128
1129             self.authenticated = False
1130
1131             self.log.debug(self.refcount)
1132
1133         except Exception as e:
1134             self.log.fatal(
1135                 "Fatal error logging out of Juju Controller: {}".format(e)
1136             )
1137             raise e
1138         return True
1139
1140     async def disconnect_model(self, model):
1141         self.log.debug("Disconnecting model {}".format(model))
1142         if model in self.models:
1143             print("Disconnecting model")
1144             await self.models[model].disconnect()
1145             self.refcount['model'] -= 1
1146             self.models[model] = None
1147
1148     # async def remove_application(self, name):
1149     #     """Remove the application."""
1150     #     if not self.authenticated:
1151     #         await self.login()
1152     #
1153     #     app = await self.get_application(name)
1154     #     if app:
1155     #         self.log.debug("JujuApi: Destroying application {}".format(
1156     #             name,
1157     #         ))
1158     #
1159     #         await app.destroy()
1160
1161     async def remove_relation(self, a, b):
1162         """
1163         Remove a relation between two application endpoints
1164
1165         :param a An application endpoint
1166         :param b An application endpoint
1167         """
1168         if not self.authenticated:
1169             await self.login()
1170
1171         m = await self.get_model()
1172         try:
1173             m.remove_relation(a, b)
1174         finally:
1175             await m.disconnect()
1176
1177     async def resolve_error(self, model_name, application=None):
1178         """Resolve units in error state."""
1179         if not self.authenticated:
1180             await self.login()
1181
1182         model = await self.get_model(model_name)
1183
1184         app = await self.get_application(model, application)
1185         if app:
1186             self.log.debug(
1187                 "JujuApi: Resolving errors for application {}".format(
1188                     application,
1189                 )
1190             )
1191
1192             for unit in app.units:
1193                 app.resolved(retry=True)
1194
1195     async def run_action(self, model_name, application, action_name, **params):
1196         """Execute an action and return an Action object."""
1197         if not self.authenticated:
1198             await self.login()
1199         result = {
1200             'status': '',
1201             'action': {
1202                 'tag': None,
1203                 'results': None,
1204             }
1205         }
1206
1207         model = await self.get_model(model_name)
1208
1209         app = await self.get_application(model, application)
1210         if app:
1211             # We currently only have one unit per application
1212             # so use the first unit available.
1213             unit = app.units[0]
1214
1215             self.log.debug(
1216                 "JujuApi: Running Action {} against Application {}".format(
1217                     action_name,
1218                     application,
1219                 )
1220             )
1221
1222             action = await unit.run_action(action_name, **params)
1223
1224             # Wait for the action to complete
1225             await action.wait()
1226
1227             result['status'] = action.status
1228             result['action']['tag'] = action.data['id']
1229             result['action']['results'] = action.results
1230
1231         return result
1232
1233     async def set_config(self, model_name, application, config):
1234         """Apply a configuration to the application."""
1235         if not self.authenticated:
1236             await self.login()
1237
1238         app = await self.get_application(model_name, application)
1239         if app:
1240             self.log.debug("JujuApi: Setting config for Application {}".format(
1241                 application,
1242             ))
1243             await app.set_config(config)
1244
1245             # Verify the config is set
1246             newconf = await app.get_config()
1247             for key in config:
1248                 if config[key] != newconf[key]['value']:
1249                     self.log.debug("JujuApi: Config not set! Key {} Value {} doesn't match {}".format(key, config[key], newconf[key]))
1250
1251     # async def set_parameter(self, parameter, value, application=None):
1252     #     """Set a config parameter for a service."""
1253     #     if not self.authenticated:
1254     #         await self.login()
1255     #
1256     #     self.log.debug("JujuApi: Setting {}={} for Application {}".format(
1257     #         parameter,
1258     #         value,
1259     #         application,
1260     #     ))
1261     #     return await self.apply_config(
1262     #         {parameter: value},
1263     #         application=application,
1264         # )
1265
1266     async def wait_for_application(self, model_name, application_name,
1267                                    timeout=300):
1268         """Wait for an application to become active."""
1269         if not self.authenticated:
1270             await self.login()
1271
1272         model = await self.get_model(model_name)
1273
1274         app = await self.get_application(model, application_name)
1275         self.log.debug("Application: {}".format(app))
1276         if app:
1277             self.log.debug(
1278                 "JujuApi: Waiting {} seconds for Application {}".format(
1279                     timeout,
1280                     application_name,
1281                 )
1282             )
1283
1284             await model.block_until(
1285                 lambda: all(
1286                     unit.agent_status == 'idle' and unit.workload_status in
1287                     ['active', 'unknown'] for unit in app.units
1288                 ),
1289                 timeout=timeout
1290             )