n2vc/n2vc_juju_conn.py

   1 ##
   2 # Copyright 2019 Telefonica Investigacion y Desarrollo, S.A.U.
   3 # This file is part of OSM
   4 # All Rights Reserved.
   5 #
   6 # Licensed under the Apache License, Version 2.0 (the "License");
   7 # you may not use this file except in compliance with the License.
   8 # You may obtain a copy of the License at
   9 #
  10 #    http://www.apache.org/licenses/LICENSE-2.0
  11 #
  12 # Unless required by applicable law or agreed to in writing, software
  13 # distributed under the License is distributed on an "AS IS" BASIS,
  14 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
  15 # implied.
  16 # See the License for the specific language governing permissions and
  17 # limitations under the License.
  18 #
  19 # For those usages not covered by the Apache License, Version 2.0 please
  20 # contact with: nfvlabs@tid.es
  21 ##
  22
  23 import asyncio
  24 import logging
  25
  26 from n2vc.config import EnvironConfig
  27 from n2vc.definitions import RelationEndpoint
  28 from n2vc.exceptions import (
  29     N2VCBadArgumentsException,
  30     N2VCException,
  31     N2VCConnectionException,
  32     N2VCExecutionException,
  33     N2VCApplicationExists,
  34     JujuApplicationExists,
  35     # N2VCNotFound,
  36     MethodNotImplemented,
  37 )
  38 from n2vc.n2vc_conn import N2VCConnector
  39 from n2vc.n2vc_conn import obj_to_dict, obj_to_yaml
  40 from n2vc.libjuju import Libjuju
  41 from n2vc.store import MotorStore
  42 from n2vc.utils import get_ee_id_components, generate_random_alfanum_string
  43 from n2vc.vca.connection import get_connection
  44 from retrying_async import retry
  45 from typing import Tuple
  46
  47
  48 class N2VCJujuConnector(N2VCConnector):
  49
  50     """
  51     ####################################################################################
  52     ################################### P U B L I C ####################################
  53     ####################################################################################
  54     """
  55
  56     BUILT_IN_CLOUDS = ["localhost", "microk8s"]
  57     libjuju = None
  58
  59     def __init__(
  60         self,
  61         db: object,
  62         fs: object,
  63         log: object = None,
  64         on_update_db=None,
  65     ):
  66         """
  67         Constructor
  68
  69         :param: db: Database object from osm_common
  70         :param: fs: Filesystem object from osm_common
  71         :param: log: Logger
  72         :param: on_update_db: Callback function to be called for updating the database.
  73         """
  74
  75         # parent class constructor
  76         N2VCConnector.__init__(self, db=db, fs=fs, log=log, on_update_db=on_update_db)
  77
  78         # silence websocket traffic log
  79         logging.getLogger("websockets.protocol").setLevel(logging.INFO)
  80         logging.getLogger("juju.client.connection").setLevel(logging.WARN)
  81         logging.getLogger("model").setLevel(logging.WARN)
  82
  83         self.log.info("Initializing N2VC juju connector...")
  84
  85         db_uri = EnvironConfig(prefixes=["OSMLCM_", "OSMMON_"]).get("database_uri")
  86         self._store = MotorStore(db_uri)
  87         self.loading_libjuju = asyncio.Lock()
  88         self.delete_namespace_locks = {}
  89         self.log.info("N2VC juju connector initialized")
  90
  91     async def get_status(
  92         self, namespace: str, yaml_format: bool = True, vca_id: str = None
  93     ):
  94         """
  95         Get status from all juju models from a VCA
  96
  97         :param namespace: we obtain ns from namespace
  98         :param yaml_format: returns a yaml string
  99         :param: vca_id: VCA ID from which the status will be retrieved.
 100         """
 101         # TODO: Review where is this function used. It is not optimal at all to get the status
 102         #       from all the juju models of a particular VCA. Additionally, these models might
 103         #       not have been deployed by OSM, in that case we are getting information from
 104         #       deployments outside of OSM's scope.
 105
 106         # self.log.info('Getting NS status. namespace: {}'.format(namespace))
 107         libjuju = await self._get_libjuju(vca_id)
 108
 109         _nsi_id, ns_id, _vnf_id, _vdu_id, _vdu_count = self._get_namespace_components(
 110             namespace=namespace
 111         )
 112         # model name is ns_id
 113         model_name = ns_id
 114         if model_name is None:
 115             msg = "Namespace {} not valid".format(namespace)
 116             self.log.error(msg)
 117             raise N2VCBadArgumentsException(msg, ["namespace"])
 118
 119         status = {}
 120         models = await libjuju.list_models(contains=ns_id)
 121
 122         for m in models:
 123             status[m] = await libjuju.get_model_status(m)
 124
 125         if yaml_format:
 126             return obj_to_yaml(status)
 127         else:
 128             return obj_to_dict(status)
 129
 130     async def update_vca_status(self, vcastatus: dict, vca_id: str = None):
 131         """
 132         Add all configs, actions, executed actions of all applications in a model to vcastatus dict.
 133
 134         :param vcastatus: dict containing vcaStatus
 135         :param: vca_id: VCA ID
 136
 137         :return: None
 138         """
 139         try:
 140             libjuju = await self._get_libjuju(vca_id)
 141             for model_name in vcastatus:
 142                 # Adding executed actions
 143                 vcastatus[model_name][
 144                     "executedActions"
 145                 ] = await libjuju.get_executed_actions(model_name)
 146                 for application in vcastatus[model_name]["applications"]:
 147                     # Adding application actions
 148                     vcastatus[model_name]["applications"][application][
 149                         "actions"
 150                     ] = await libjuju.get_actions(application, model_name)
 151                     # Adding application configs
 152                     vcastatus[model_name]["applications"][application][
 153                         "configs"
 154                     ] = await libjuju.get_application_configs(model_name, application)
 155         except Exception as e:
 156             self.log.debug("Error in updating vca status: {}".format(str(e)))
 157
 158     async def create_execution_environment(
 159         self,
 160         namespace: str,
 161         db_dict: dict,
 162         reuse_ee_id: str = None,
 163         progress_timeout: float = None,
 164         total_timeout: float = None,
 165         vca_id: str = None,
 166     ) -> (str, dict):
 167         """
 168         Create an Execution Environment. Returns when it is created or raises an
 169         exception on failing
 170
 171         :param: namespace: Contains a dot separate string.
 172                     LCM will use: [<nsi-id>].<ns-id>.<vnf-id>.<vdu-id>[-<count>]
 173         :param: db_dict: where to write to database when the status changes.
 174             It contains a dictionary with {collection: str, filter: {},  path: str},
 175                 e.g. {collection: "nsrs", filter: {_id: <nsd-id>, path:
 176                 "_admin.deployed.VCA.3"}
 177         :param: reuse_ee_id: ee id from an older execution. It allows us to reuse an
 178                              older environment
 179         :param: progress_timeout: Progress timeout
 180         :param: total_timeout: Total timeout
 181         :param: vca_id: VCA ID
 182
 183         :returns: id of the new execution environment and credentials for it
 184                   (credentials can contains hostname, username, etc depending on underlying cloud)
 185         """
 186
 187         self.log.info(
 188             "Creating execution environment. namespace: {}, reuse_ee_id: {}".format(
 189                 namespace, reuse_ee_id
 190             )
 191         )
 192         libjuju = await self._get_libjuju(vca_id)
 193
 194         machine_id = None
 195         if reuse_ee_id:
 196             model_name, application_name, machine_id = self._get_ee_id_components(
 197                 ee_id=reuse_ee_id
 198             )
 199         else:
 200             (
 201                 _nsi_id,
 202                 ns_id,
 203                 _vnf_id,
 204                 _vdu_id,
 205                 _vdu_count,
 206             ) = self._get_namespace_components(namespace=namespace)
 207             # model name is ns_id
 208             model_name = ns_id
 209             # application name
 210             application_name = self._get_application_name(namespace=namespace)
 211
 212         self.log.debug(
 213             "model name: {}, application name:  {}, machine_id: {}".format(
 214                 model_name, application_name, machine_id
 215             )
 216         )
 217
 218         # create or reuse a new juju machine
 219         try:
 220             if not await libjuju.model_exists(model_name):
 221                 await libjuju.add_model(model_name, libjuju.vca_connection.lxd_cloud)
 222             machine, new = await libjuju.create_machine(
 223                 model_name=model_name,
 224                 machine_id=machine_id,
 225                 db_dict=db_dict,
 226                 progress_timeout=progress_timeout,
 227                 total_timeout=total_timeout,
 228             )
 229             # id for the execution environment
 230             ee_id = N2VCJujuConnector._build_ee_id(
 231                 model_name=model_name,
 232                 application_name=application_name,
 233                 machine_id=str(machine.entity_id),
 234             )
 235             self.log.debug("ee_id: {}".format(ee_id))
 236
 237             if new:
 238                 # write ee_id in database
 239                 self._write_ee_id_db(db_dict=db_dict, ee_id=ee_id)
 240
 241         except Exception as e:
 242             message = "Error creating machine on juju: {}".format(e)
 243             self.log.error(message)
 244             raise N2VCException(message=message)
 245
 246         # new machine credentials
 247         credentials = {"hostname": machine.dns_name}
 248
 249         self.log.info(
 250             "Execution environment created. ee_id: {}, credentials: {}".format(
 251                 ee_id, credentials
 252             )
 253         )
 254
 255         return ee_id, credentials
 256
 257     async def register_execution_environment(
 258         self,
 259         namespace: str,
 260         credentials: dict,
 261         db_dict: dict,
 262         progress_timeout: float = None,
 263         total_timeout: float = None,
 264         vca_id: str = None,
 265     ) -> str:
 266         """
 267         Register an existing execution environment at the VCA
 268
 269         :param: namespace: Contains a dot separate string.
 270                     LCM will use: [<nsi-id>].<ns-id>.<vnf-id>.<vdu-id>[-<count>]
 271         :param: credentials: credentials to access the existing execution environment
 272                             (it can contains hostname, username, path to private key,
 273                             etc depending on underlying cloud)
 274         :param: db_dict: where to write to database when the status changes.
 275             It contains a dictionary with {collection: str, filter: {},  path: str},
 276                 e.g. {collection: "nsrs", filter: {_id: <nsd-id>, path:
 277                 "_admin.deployed.VCA.3"}
 278         :param: reuse_ee_id: ee id from an older execution. It allows us to reuse an
 279                              older environment
 280         :param: progress_timeout: Progress timeout
 281         :param: total_timeout: Total timeout
 282         :param: vca_id: VCA ID
 283
 284         :returns: id of the execution environment
 285         """
 286         self.log.info(
 287             "Registering execution environment. namespace={}, credentials={}".format(
 288                 namespace, credentials
 289             )
 290         )
 291         libjuju = await self._get_libjuju(vca_id)
 292
 293         if credentials is None:
 294             raise N2VCBadArgumentsException(
 295                 message="credentials are mandatory", bad_args=["credentials"]
 296             )
 297         if credentials.get("hostname"):
 298             hostname = credentials["hostname"]
 299         else:
 300             raise N2VCBadArgumentsException(
 301                 message="hostname is mandatory", bad_args=["credentials.hostname"]
 302             )
 303         if credentials.get("username"):
 304             username = credentials["username"]
 305         else:
 306             raise N2VCBadArgumentsException(
 307                 message="username is mandatory", bad_args=["credentials.username"]
 308             )
 309         if "private_key_path" in credentials:
 310             private_key_path = credentials["private_key_path"]
 311         else:
 312             # if not passed as argument, use generated private key path
 313             private_key_path = self.private_key_path
 314
 315         _nsi_id, ns_id, _vnf_id, _vdu_id, _vdu_count = self._get_namespace_components(
 316             namespace=namespace
 317         )
 318
 319         # model name
 320         model_name = ns_id
 321         # application name
 322         application_name = self._get_application_name(namespace=namespace)
 323
 324         # register machine on juju
 325         try:
 326             if not await libjuju.model_exists(model_name):
 327                 await libjuju.add_model(model_name, libjuju.vca_connection.lxd_cloud)
 328             machine_id = await libjuju.provision_machine(
 329                 model_name=model_name,
 330                 hostname=hostname,
 331                 username=username,
 332                 private_key_path=private_key_path,
 333                 db_dict=db_dict,
 334                 progress_timeout=progress_timeout,
 335                 total_timeout=total_timeout,
 336             )
 337         except Exception as e:
 338             self.log.error("Error registering machine: {}".format(e))
 339             raise N2VCException(
 340                 message="Error registering machine on juju: {}".format(e)
 341             )
 342
 343         self.log.info("Machine registered: {}".format(machine_id))
 344
 345         # id for the execution environment
 346         ee_id = N2VCJujuConnector._build_ee_id(
 347             model_name=model_name,
 348             application_name=application_name,
 349             machine_id=str(machine_id),
 350         )
 351
 352         self.log.info("Execution environment registered. ee_id: {}".format(ee_id))
 353
 354         return ee_id
 355
 356     # In case of native_charm is being deployed, if JujuApplicationExists error happens
 357     # it will try to add_unit
 358     @retry(attempts=3, delay=5, retry_exceptions=(N2VCApplicationExists,), timeout=None)
 359     async def install_configuration_sw(
 360         self,
 361         ee_id: str,
 362         artifact_path: str,
 363         db_dict: dict,
 364         progress_timeout: float = None,
 365         total_timeout: float = None,
 366         config: dict = None,
 367         num_units: int = 1,
 368         vca_id: str = None,
 369         scaling_out: bool = False,
 370         vca_type: str = None,
 371     ):
 372         """
 373         Install the software inside the execution environment identified by ee_id
 374
 375         :param: ee_id: the id of the execution environment returned by
 376                           create_execution_environment or register_execution_environment
 377         :param: artifact_path: where to locate the artifacts (parent folder) using
 378                                   the self.fs
 379                                   the final artifact path will be a combination of this
 380                                   artifact_path and additional string from the config_dict
 381                                   (e.g. charm name)
 382         :param: db_dict: where to write into database when the status changes.
 383                              It contains a dict with
 384                                 {collection: <str>, filter: {},  path: <str>},
 385                                 e.g. {collection: "nsrs", filter:
 386                                     {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
 387         :param: progress_timeout: Progress timeout
 388         :param: total_timeout: Total timeout
 389         :param: config: Dictionary with deployment config information.
 390         :param: num_units: Number of units to deploy of a particular charm.
 391         :param: vca_id: VCA ID
 392         :param: scaling_out: Boolean to indicate if it is a scaling out operation
 393         :param: vca_type: VCA type
 394         """
 395
 396         self.log.info(
 397             (
 398                 "Installing configuration sw on ee_id: {}, "
 399                 "artifact path: {}, db_dict: {}"
 400             ).format(ee_id, artifact_path, db_dict)
 401         )
 402         libjuju = await self._get_libjuju(vca_id)
 403
 404         # check arguments
 405         if ee_id is None or len(ee_id) == 0:
 406             raise N2VCBadArgumentsException(
 407                 message="ee_id is mandatory", bad_args=["ee_id"]
 408             )
 409         if artifact_path is None or len(artifact_path) == 0:
 410             raise N2VCBadArgumentsException(
 411                 message="artifact_path is mandatory", bad_args=["artifact_path"]
 412             )
 413         if db_dict is None:
 414             raise N2VCBadArgumentsException(
 415                 message="db_dict is mandatory", bad_args=["db_dict"]
 416             )
 417
 418         try:
 419             (
 420                 model_name,
 421                 application_name,
 422                 machine_id,
 423             ) = N2VCJujuConnector._get_ee_id_components(ee_id=ee_id)
 424             self.log.debug(
 425                 "model: {}, application: {}, machine: {}".format(
 426                     model_name, application_name, machine_id
 427                 )
 428             )
 429         except Exception:
 430             raise N2VCBadArgumentsException(
 431                 message="ee_id={} is not a valid execution environment id".format(
 432                     ee_id
 433                 ),
 434                 bad_args=["ee_id"],
 435             )
 436
 437         # remove // in charm path
 438         while artifact_path.find("//") >= 0:
 439             artifact_path = artifact_path.replace("//", "/")
 440
 441         # check charm path
 442         if not self.fs.file_exists(artifact_path):
 443             msg = "artifact path does not exist: {}".format(artifact_path)
 444             raise N2VCBadArgumentsException(message=msg, bad_args=["artifact_path"])
 445
 446         if artifact_path.startswith("/"):
 447             full_path = self.fs.path + artifact_path
 448         else:
 449             full_path = self.fs.path + "/" + artifact_path
 450
 451         try:
 452             if vca_type == "native_charm" and await libjuju.check_application_exists(
 453                 model_name, application_name
 454             ):
 455                 await libjuju.add_unit(
 456                     application_name=application_name,
 457                     model_name=model_name,
 458                     machine_id=machine_id,
 459                     db_dict=db_dict,
 460                     progress_timeout=progress_timeout,
 461                     total_timeout=total_timeout,
 462                 )
 463             else:
 464                 await libjuju.deploy_charm(
 465                     model_name=model_name,
 466                     application_name=application_name,
 467                     path=full_path,
 468                     machine_id=machine_id,
 469                     db_dict=db_dict,
 470                     progress_timeout=progress_timeout,
 471                     total_timeout=total_timeout,
 472                     config=config,
 473                     num_units=num_units,
 474                 )
 475         except JujuApplicationExists as e:
 476             raise N2VCApplicationExists(
 477                 message="Error deploying charm into ee={} : {}".format(ee_id, e.message)
 478             )
 479         except Exception as e:
 480             raise N2VCException(
 481                 message="Error deploying charm into ee={} : {}".format(ee_id, e)
 482             )
 483
 484         self.log.info("Configuration sw installed")
 485
 486     async def install_k8s_proxy_charm(
 487         self,
 488         charm_name: str,
 489         namespace: str,
 490         artifact_path: str,
 491         db_dict: dict,
 492         progress_timeout: float = None,
 493         total_timeout: float = None,
 494         config: dict = None,
 495         vca_id: str = None,
 496     ) -> str:
 497         """
 498         Install a k8s proxy charm
 499
 500         :param charm_name: Name of the charm being deployed
 501         :param namespace: collection of all the uuids related to the charm.
 502         :param str artifact_path: where to locate the artifacts (parent folder) using
 503             the self.fs
 504             the final artifact path will be a combination of this artifact_path and
 505             additional string from the config_dict (e.g. charm name)
 506         :param dict db_dict: where to write into database when the status changes.
 507                         It contains a dict with
 508                             {collection: <str>, filter: {},  path: <str>},
 509                             e.g. {collection: "nsrs", filter:
 510                                 {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
 511         :param: progress_timeout: Progress timeout
 512         :param: total_timeout: Total timeout
 513         :param config: Dictionary with additional configuration
 514         :param vca_id: VCA ID
 515
 516         :returns ee_id: execution environment id.
 517         """
 518         self.log.info(
 519             "Installing k8s proxy charm: {}, artifact path: {}, db_dict: {}".format(
 520                 charm_name, artifact_path, db_dict
 521             )
 522         )
 523         libjuju = await self._get_libjuju(vca_id)
 524
 525         if artifact_path is None or len(artifact_path) == 0:
 526             raise N2VCBadArgumentsException(
 527                 message="artifact_path is mandatory", bad_args=["artifact_path"]
 528             )
 529         if db_dict is None:
 530             raise N2VCBadArgumentsException(
 531                 message="db_dict is mandatory", bad_args=["db_dict"]
 532             )
 533
 534         # remove // in charm path
 535         while artifact_path.find("//") >= 0:
 536             artifact_path = artifact_path.replace("//", "/")
 537
 538         # check charm path
 539         if not self.fs.file_exists(artifact_path):
 540             msg = "artifact path does not exist: {}".format(artifact_path)
 541             raise N2VCBadArgumentsException(message=msg, bad_args=["artifact_path"])
 542
 543         if artifact_path.startswith("/"):
 544             full_path = self.fs.path + artifact_path
 545         else:
 546             full_path = self.fs.path + "/" + artifact_path
 547
 548         _, ns_id, _, _, _ = self._get_namespace_components(namespace=namespace)
 549         model_name = "{}-k8s".format(ns_id)
 550         if not await libjuju.model_exists(model_name):
 551             await libjuju.add_model(model_name, libjuju.vca_connection.k8s_cloud)
 552         application_name = self._get_application_name(namespace)
 553
 554         try:
 555             await libjuju.deploy_charm(
 556                 model_name=model_name,
 557                 application_name=application_name,
 558                 path=full_path,
 559                 machine_id=None,
 560                 db_dict=db_dict,
 561                 progress_timeout=progress_timeout,
 562                 total_timeout=total_timeout,
 563                 config=config,
 564             )
 565         except Exception as e:
 566             raise N2VCException(message="Error deploying charm: {}".format(e))
 567
 568         self.log.info("K8s proxy charm installed")
 569         ee_id = N2VCJujuConnector._build_ee_id(
 570             model_name=model_name, application_name=application_name, machine_id="k8s"
 571         )
 572
 573         self._write_ee_id_db(db_dict=db_dict, ee_id=ee_id)
 574
 575         return ee_id
 576
 577     async def get_ee_ssh_public__key(
 578         self,
 579         ee_id: str,
 580         db_dict: dict,
 581         progress_timeout: float = None,
 582         total_timeout: float = None,
 583         vca_id: str = None,
 584     ) -> str:
 585         """
 586         Get Execution environment ssh public key
 587
 588         :param: ee_id: the id of the execution environment returned by
 589             create_execution_environment or register_execution_environment
 590         :param: db_dict: where to write into database when the status changes.
 591                             It contains a dict with
 592                                 {collection: <str>, filter: {},  path: <str>},
 593                                 e.g. {collection: "nsrs", filter:
 594                                     {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
 595         :param: progress_timeout: Progress timeout
 596         :param: total_timeout: Total timeout
 597         :param vca_id: VCA ID
 598         :returns: public key of the execution environment
 599                     For the case of juju proxy charm ssh-layered, it is the one
 600                     returned by 'get-ssh-public-key' primitive.
 601                     It raises a N2VC exception if fails
 602         """
 603
 604         self.log.info(
 605             (
 606                 "Generating priv/pub key pair and get pub key on ee_id: {}, db_dict: {}"
 607             ).format(ee_id, db_dict)
 608         )
 609         libjuju = await self._get_libjuju(vca_id)
 610
 611         # check arguments
 612         if ee_id is None or len(ee_id) == 0:
 613             raise N2VCBadArgumentsException(
 614                 message="ee_id is mandatory", bad_args=["ee_id"]
 615             )
 616         if db_dict is None:
 617             raise N2VCBadArgumentsException(
 618                 message="db_dict is mandatory", bad_args=["db_dict"]
 619             )
 620
 621         try:
 622             (
 623                 model_name,
 624                 application_name,
 625                 machine_id,
 626             ) = N2VCJujuConnector._get_ee_id_components(ee_id=ee_id)
 627             self.log.debug(
 628                 "model: {}, application: {}, machine: {}".format(
 629                     model_name, application_name, machine_id
 630                 )
 631             )
 632         except Exception:
 633             raise N2VCBadArgumentsException(
 634                 message="ee_id={} is not a valid execution environment id".format(
 635                     ee_id
 636                 ),
 637                 bad_args=["ee_id"],
 638             )
 639
 640         # try to execute ssh layer primitives (if exist):
 641         #       generate-ssh-key
 642         #       get-ssh-public-key
 643
 644         output = None
 645
 646         application_name = N2VCJujuConnector._format_app_name(application_name)
 647
 648         # execute action: generate-ssh-key
 649         try:
 650             output, _status = await libjuju.execute_action(
 651                 model_name=model_name,
 652                 application_name=application_name,
 653                 action_name="generate-ssh-key",
 654                 db_dict=db_dict,
 655                 progress_timeout=progress_timeout,
 656                 total_timeout=total_timeout,
 657             )
 658         except Exception as e:
 659             self.log.info(
 660                 "Skipping exception while executing action generate-ssh-key: {}".format(
 661                     e
 662                 )
 663             )
 664
 665         # execute action: get-ssh-public-key
 666         try:
 667             output, _status = await libjuju.execute_action(
 668                 model_name=model_name,
 669                 application_name=application_name,
 670                 action_name="get-ssh-public-key",
 671                 db_dict=db_dict,
 672                 progress_timeout=progress_timeout,
 673                 total_timeout=total_timeout,
 674             )
 675         except Exception as e:
 676             msg = "Cannot execute action get-ssh-public-key: {}\n".format(e)
 677             self.log.info(msg)
 678             raise N2VCExecutionException(e, primitive_name="get-ssh-public-key")
 679
 680         # return public key if exists
 681         return output["pubkey"] if "pubkey" in output else output
 682
 683     async def get_metrics(
 684         self, model_name: str, application_name: str, vca_id: str = None
 685     ) -> dict:
 686         """
 687         Get metrics from application
 688
 689         :param: model_name: Model name
 690         :param: application_name: Application name
 691         :param: vca_id: VCA ID
 692
 693         :return: Dictionary with obtained metrics
 694         """
 695         libjuju = await self._get_libjuju(vca_id)
 696         return await libjuju.get_metrics(model_name, application_name)
 697
 698     async def add_relation(
 699         self, provider: RelationEndpoint, requirer: RelationEndpoint
 700     ):
 701         """
 702         Add relation between two charmed endpoints
 703
 704         :param: provider: Provider relation endpoint
 705         :param: requirer: Requirer relation endpoint
 706         """
 707         self.log.debug(f"adding new relation between {provider} and {requirer}")
 708         cross_model_relation = (
 709             provider.model_name != requirer.model_name
 710             or provider.vca_id != requirer.vca_id
 711         )
 712         try:
 713             if cross_model_relation:
 714                 # Cross-model relation
 715                 provider_libjuju = await self._get_libjuju(provider.vca_id)
 716                 requirer_libjuju = await self._get_libjuju(requirer.vca_id)
 717                 offer = await provider_libjuju.offer(provider)
 718                 if offer:
 719                     saas_name = await requirer_libjuju.consume(
 720                         requirer.model_name, offer, provider_libjuju
 721                     )
 722                     await requirer_libjuju.add_relation(
 723                         requirer.model_name, requirer.endpoint, saas_name
 724                     )
 725             else:
 726                 # Standard relation
 727                 vca_id = provider.vca_id
 728                 model = provider.model_name
 729                 libjuju = await self._get_libjuju(vca_id)
 730                 # add juju relations between two applications
 731                 await libjuju.add_relation(
 732                     model_name=model,
 733                     endpoint_1=provider.endpoint,
 734                     endpoint_2=requirer.endpoint,
 735                 )
 736         except Exception as e:
 737             message = f"Error adding relation between {provider} and {requirer}: {e}"
 738             self.log.error(message)
 739             raise N2VCException(message=message)
 740
 741     async def remove_relation(self):
 742         # TODO
 743         self.log.info("Method not implemented yet")
 744         raise MethodNotImplemented()
 745
 746     async def deregister_execution_environments(self):
 747         self.log.info("Method not implemented yet")
 748         raise MethodNotImplemented()
 749
 750     async def delete_namespace(
 751         self,
 752         namespace: str,
 753         db_dict: dict = None,
 754         total_timeout: float = None,
 755         vca_id: str = None,
 756     ):
 757         """
 758         Remove a network scenario and its execution environments
 759         :param: namespace: [<nsi-id>].<ns-id>
 760         :param: db_dict: where to write into database when the status changes.
 761                         It contains a dict with
 762                             {collection: <str>, filter: {},  path: <str>},
 763                             e.g. {collection: "nsrs", filter:
 764                                 {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
 765         :param: total_timeout: Total timeout
 766         :param: vca_id: VCA ID
 767         """
 768         self.log.info("Deleting namespace={}".format(namespace))
 769         will_not_delete = False
 770         if namespace not in self.delete_namespace_locks:
 771             self.delete_namespace_locks[namespace] = asyncio.Lock()
 772         delete_lock = self.delete_namespace_locks[namespace]
 773
 774         while delete_lock.locked():
 775             will_not_delete = True
 776             await asyncio.sleep(0.1)
 777
 778         if will_not_delete:
 779             self.log.info("Namespace {} deleted by another worker.".format(namespace))
 780             return
 781
 782         try:
 783             async with delete_lock:
 784                 libjuju = await self._get_libjuju(vca_id)
 785
 786                 # check arguments
 787                 if namespace is None:
 788                     raise N2VCBadArgumentsException(
 789                         message="namespace is mandatory", bad_args=["namespace"]
 790                     )
 791
 792                 (
 793                     _nsi_id,
 794                     ns_id,
 795                     _vnf_id,
 796                     _vdu_id,
 797                     _vdu_count,
 798                 ) = self._get_namespace_components(namespace=namespace)
 799                 if ns_id is not None:
 800                     try:
 801                         models = await libjuju.list_models(contains=ns_id)
 802                         for model in models:
 803                             await libjuju.destroy_model(
 804                                 model_name=model, total_timeout=total_timeout
 805                             )
 806                     except Exception as e:
 807                         self.log.error(f"Error deleting namespace {namespace} : {e}")
 808                         raise N2VCException(
 809                             message="Error deleting namespace {} : {}".format(
 810                                 namespace, e
 811                             )
 812                         )
 813                 else:
 814                     raise N2VCBadArgumentsException(
 815                         message="only ns_id is permitted to delete yet",
 816                         bad_args=["namespace"],
 817                     )
 818         except Exception as e:
 819             self.log.error(f"Error deleting namespace {namespace} : {e}")
 820             raise e
 821         finally:
 822             self.delete_namespace_locks.pop(namespace)
 823         self.log.info("Namespace {} deleted".format(namespace))
 824
 825     async def delete_execution_environment(
 826         self,
 827         ee_id: str,
 828         db_dict: dict = None,
 829         total_timeout: float = None,
 830         scaling_in: bool = False,
 831         vca_type: str = None,
 832         vca_id: str = None,
 833     ):
 834         """
 835         Delete an execution environment
 836         :param str ee_id: id of the execution environment to delete
 837         :param dict db_dict: where to write into database when the status changes.
 838                         It contains a dict with
 839                             {collection: <str>, filter: {},  path: <str>},
 840                             e.g. {collection: "nsrs", filter:
 841                                 {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
 842         :param: total_timeout: Total timeout
 843         :param: scaling_in: Boolean to indicate if it is a scaling in operation
 844         :param: vca_type: VCA type
 845         :param: vca_id: VCA ID
 846         """
 847         self.log.info("Deleting execution environment ee_id={}".format(ee_id))
 848         libjuju = await self._get_libjuju(vca_id)
 849
 850         # check arguments
 851         if ee_id is None:
 852             raise N2VCBadArgumentsException(
 853                 message="ee_id is mandatory", bad_args=["ee_id"]
 854             )
 855
 856         model_name, application_name, machine_id = self._get_ee_id_components(
 857             ee_id=ee_id
 858         )
 859         try:
 860             if not scaling_in:
 861                 # destroy the model
 862                 await libjuju.destroy_model(
 863                     model_name=model_name, total_timeout=total_timeout
 864                 )
 865             elif vca_type == "native_charm" and scaling_in:
 866                 # destroy the unit in the application
 867                 await libjuju.destroy_unit(
 868                     application_name=application_name,
 869                     model_name=model_name,
 870                     machine_id=machine_id,
 871                     total_timeout=total_timeout,
 872                 )
 873             else:
 874                 # destroy the application
 875                 await libjuju.destroy_application(
 876                     model_name=model_name,
 877                     application_name=application_name,
 878                     total_timeout=total_timeout,
 879                 )
 880         except Exception as e:
 881             raise N2VCException(
 882                 message=(
 883                     "Error deleting execution environment {} (application {}) : {}"
 884                 ).format(ee_id, application_name, e)
 885             )
 886
 887         self.log.info("Execution environment {} deleted".format(ee_id))
 888
 889     async def exec_primitive(
 890         self,
 891         ee_id: str,
 892         primitive_name: str,
 893         params_dict: dict,
 894         db_dict: dict = None,
 895         progress_timeout: float = None,
 896         total_timeout: float = None,
 897         vca_id: str = None,
 898         vca_type: str = None,
 899     ) -> str:
 900         """
 901         Execute a primitive in the execution environment
 902
 903         :param: ee_id: the one returned by create_execution_environment or
 904             register_execution_environment
 905         :param: primitive_name: must be one defined in the software. There is one
 906             called 'config', where, for the proxy case, the 'credentials' of VM are
 907             provided
 908         :param: params_dict: parameters of the action
 909         :param: db_dict: where to write into database when the status changes.
 910                         It contains a dict with
 911                             {collection: <str>, filter: {},  path: <str>},
 912                             e.g. {collection: "nsrs", filter:
 913                                 {_id: <nsd-id>, path: "_admin.deployed.VCA.3"}
 914         :param: progress_timeout: Progress timeout
 915         :param: total_timeout: Total timeout
 916         :param: vca_id: VCA ID
 917         :param: vca_type: VCA type
 918         :returns str: primitive result, if ok. It raises exceptions in case of fail
 919         """
 920
 921         self.log.info(
 922             "Executing primitive: {} on ee: {}, params: {}".format(
 923                 primitive_name, ee_id, params_dict
 924             )
 925         )
 926         libjuju = await self._get_libjuju(vca_id)
 927
 928         # check arguments
 929         if ee_id is None or len(ee_id) == 0:
 930             raise N2VCBadArgumentsException(
 931                 message="ee_id is mandatory", bad_args=["ee_id"]
 932             )
 933         if primitive_name is None or len(primitive_name) == 0:
 934             raise N2VCBadArgumentsException(
 935                 message="action_name is mandatory", bad_args=["action_name"]
 936             )
 937         if params_dict is None:
 938             params_dict = dict()
 939
 940         try:
 941             (
 942                 model_name,
 943                 application_name,
 944                 machine_id,
 945             ) = N2VCJujuConnector._get_ee_id_components(ee_id=ee_id)
 946             # To run action on the leader unit in libjuju.execute_action function,
 947             # machine_id must be set to None if vca_type is not native_charm
 948             if vca_type != "native_charm":
 949                 machine_id = None
 950         except Exception:
 951             raise N2VCBadArgumentsException(
 952                 message="ee_id={} is not a valid execution environment id".format(
 953                     ee_id
 954                 ),
 955                 bad_args=["ee_id"],
 956             )
 957
 958         if primitive_name == "config":
 959             # Special case: config primitive
 960             try:
 961                 await libjuju.configure_application(
 962                     model_name=model_name,
 963                     application_name=application_name,
 964                     config=params_dict,
 965                 )
 966                 actions = await libjuju.get_actions(
 967                     application_name=application_name, model_name=model_name
 968                 )
 969                 self.log.debug(
 970                     "Application {} has these actions: {}".format(
 971                         application_name, actions
 972                     )
 973                 )
 974                 if "verify-ssh-credentials" in actions:
 975                     # execute verify-credentials
 976                     num_retries = 20
 977                     retry_timeout = 15.0
 978                     for _ in range(num_retries):
 979                         try:
 980                             self.log.debug("Executing action verify-ssh-credentials...")
 981                             output, ok = await libjuju.execute_action(
 982                                 model_name=model_name,
 983                                 application_name=application_name,
 984                                 action_name="verify-ssh-credentials",
 985                                 db_dict=db_dict,
 986                                 progress_timeout=progress_timeout,
 987                                 total_timeout=total_timeout,
 988                             )
 989
 990                             if ok == "failed":
 991                                 self.log.debug(
 992                                     "Error executing verify-ssh-credentials: {}. Retrying..."
 993                                 )
 994                                 await asyncio.sleep(retry_timeout)
 995
 996                                 continue
 997                             self.log.debug("Result: {}, output: {}".format(ok, output))
 998                             break
 999                         except asyncio.CancelledError:
1000                             raise
1001                     else:
1002                         self.log.error(
1003                             "Error executing verify-ssh-credentials after {} retries. ".format(
1004                                 num_retries
1005                             )
1006                         )
1007                 else:
1008                     msg = "Action verify-ssh-credentials does not exist in application {}".format(
1009                         application_name
1010                     )
1011                     self.log.debug(msg=msg)
1012             except Exception as e:
1013                 self.log.error("Error configuring juju application: {}".format(e))
1014                 raise N2VCExecutionException(
1015                     message="Error configuring application into ee={} : {}".format(
1016                         ee_id, e
1017                     ),
1018                     primitive_name=primitive_name,
1019                 )
1020             return "CONFIG OK"
1021         else:
1022             try:
1023                 output, status = await libjuju.execute_action(
1024                     model_name=model_name,
1025                     application_name=application_name,
1026                     action_name=primitive_name,
1027                     db_dict=db_dict,
1028                     machine_id=machine_id,
1029                     progress_timeout=progress_timeout,
1030                     total_timeout=total_timeout,
1031                     **params_dict,
1032                 )
1033                 if status == "completed":
1034                     return output
1035                 else:
1036                     if "output" in output:
1037                         raise Exception(f'{status}: {output["output"]}')
1038                     else:
1039                         raise Exception(
1040                             f"{status}: No further information received from action"
1041                         )
1042
1043             except Exception as e:
1044                 self.log.error(f"Error executing primitive {primitive_name}: {e}")
1045                 raise N2VCExecutionException(
1046                     message=f"Error executing primitive {primitive_name} in ee={ee_id}: {e}",
1047                     primitive_name=primitive_name,
1048                 )
1049
1050     async def upgrade_charm(
1051         self,
1052         ee_id: str = None,
1053         path: str = None,
1054         charm_id: str = None,
1055         charm_type: str = None,
1056         timeout: float = None,
1057     ) -> str:
1058         """This method upgrade charms in VNFs
1059
1060         Args:
1061             ee_id:  Execution environment id
1062             path:   Local path to the charm
1063             charm_id:   charm-id
1064             charm_type: Charm type can be lxc-proxy-charm, native-charm or k8s-proxy-charm
1065             timeout: (Float)    Timeout for the ns update operation
1066
1067         Returns:
1068             The output of the update operation if status equals to "completed"
1069
1070         """
1071         self.log.info("Upgrading charm: {} on ee: {}".format(path, ee_id))
1072         libjuju = await self._get_libjuju(charm_id)
1073
1074         # check arguments
1075         if ee_id is None or len(ee_id) == 0:
1076             raise N2VCBadArgumentsException(
1077                 message="ee_id is mandatory", bad_args=["ee_id"]
1078             )
1079         try:
1080             (
1081                 model_name,
1082                 application_name,
1083                 machine_id,
1084             ) = N2VCJujuConnector._get_ee_id_components(ee_id=ee_id)
1085
1086         except Exception:
1087             raise N2VCBadArgumentsException(
1088                 message="ee_id={} is not a valid execution environment id".format(
1089                     ee_id
1090                 ),
1091                 bad_args=["ee_id"],
1092             )
1093
1094         try:
1095             await libjuju.upgrade_charm(
1096                 application_name=application_name,
1097                 path=path,
1098                 model_name=model_name,
1099                 total_timeout=timeout,
1100             )
1101
1102             return f"Charm upgraded with application name {application_name}"
1103
1104         except Exception as e:
1105             self.log.error("Error upgrading charm {}: {}".format(path, e))
1106
1107             raise N2VCException(
1108                 message="Error upgrading charm {} in ee={} : {}".format(path, ee_id, e)
1109             )
1110
1111     async def disconnect(self, vca_id: str = None):
1112         """
1113         Disconnect from VCA
1114
1115         :param: vca_id: VCA ID
1116         """
1117         self.log.info("closing juju N2VC...")
1118         libjuju = await self._get_libjuju(vca_id)
1119         try:
1120             await libjuju.disconnect()
1121         except Exception as e:
1122             raise N2VCConnectionException(
1123                 message="Error disconnecting controller: {}".format(e),
1124                 url=libjuju.vca_connection.data.endpoints,
1125             )
1126
1127     """
1128 ####################################################################################
1129 ################################### P R I V A T E ##################################
1130 ####################################################################################
1131     """
1132
1133     async def _get_libjuju(self, vca_id: str = None) -> Libjuju:
1134         """
1135         Get libjuju object
1136
1137         :param: vca_id: VCA ID
1138                         If None, get a libjuju object with a Connection to the default VCA
1139                         Else, geta libjuju object with a Connection to the specified VCA
1140         """
1141         if not vca_id:
1142             while self.loading_libjuju.locked():
1143                 await asyncio.sleep(0.1)
1144             if not self.libjuju:
1145                 async with self.loading_libjuju:
1146                     vca_connection = await get_connection(self._store)
1147                     self.libjuju = Libjuju(vca_connection, log=self.log)
1148             return self.libjuju
1149         else:
1150             vca_connection = await get_connection(self._store, vca_id)
1151             return Libjuju(vca_connection, log=self.log, n2vc=self)
1152
1153     def _write_ee_id_db(self, db_dict: dict, ee_id: str):
1154         # write ee_id to database: _admin.deployed.VCA.x
1155         try:
1156             the_table = db_dict["collection"]
1157             the_filter = db_dict["filter"]
1158             the_path = db_dict["path"]
1159             if not the_path[-1] == ".":
1160                 the_path = the_path + "."
1161             update_dict = {the_path + "ee_id": ee_id}
1162             # self.log.debug('Writing ee_id to database: {}'.format(the_path))
1163             self.db.set_one(
1164                 table=the_table,
1165                 q_filter=the_filter,
1166                 update_dict=update_dict,
1167                 fail_on_empty=True,
1168             )
1169         except asyncio.CancelledError:
1170             raise
1171         except Exception as e:
1172             self.log.error("Error writing ee_id to database: {}".format(e))
1173
1174     @staticmethod
1175     def _build_ee_id(model_name: str, application_name: str, machine_id: str):
1176         """
1177         Build an execution environment id form model, application and machine
1178         :param model_name:
1179         :param application_name:
1180         :param machine_id:
1181         :return:
1182         """
1183         # id for the execution environment
1184         return "{}.{}.{}".format(model_name, application_name, machine_id)
1185
1186     @staticmethod
1187     def _get_ee_id_components(ee_id: str) -> (str, str, str):
1188         """
1189         Get model, application and machine components from an execution environment id
1190         :param ee_id:
1191         :return: model_name, application_name, machine_id
1192         """
1193
1194         return get_ee_id_components(ee_id)
1195
1196     @staticmethod
1197     def _find_charm_level(vnf_id: str, vdu_id: str) -> str:
1198         """Decides the charm level.
1199         Args:
1200             vnf_id  (str):  VNF id
1201             vdu_id  (str):  VDU id
1202
1203         Returns:
1204             charm_level (str):  ns-level or vnf-level or vdu-level
1205         """
1206         if vdu_id and not vnf_id:
1207             raise N2VCException(message="If vdu-id exists, vnf-id should be provided.")
1208         if vnf_id and vdu_id:
1209             return "vdu-level"
1210         if vnf_id and not vdu_id:
1211             return "vnf-level"
1212         if not vnf_id and not vdu_id:
1213             return "ns-level"
1214
1215     @staticmethod
1216     def _generate_backward_compatible_application_name(
1217         vnf_id: str, vdu_id: str, vdu_count: str
1218     ) -> str:
1219         """Generate backward compatible application name
1220          by limiting the app name to 50 characters.
1221
1222         Args:
1223             vnf_id  (str):  VNF ID
1224             vdu_id  (str):  VDU ID
1225             vdu_count   (str):  vdu-count-index
1226
1227         Returns:
1228             application_name (str): generated application name
1229
1230         """
1231         if vnf_id is None or len(vnf_id) == 0:
1232             vnf_id = ""
1233         else:
1234             # Shorten the vnf_id to its last twelve characters
1235             vnf_id = "vnf-" + vnf_id[-12:]
1236
1237         if vdu_id is None or len(vdu_id) == 0:
1238             vdu_id = ""
1239         else:
1240             # Shorten the vdu_id to its last twelve characters
1241             vdu_id = "-vdu-" + vdu_id[-12:]
1242
1243         if vdu_count is None or len(vdu_count) == 0:
1244             vdu_count = ""
1245         else:
1246             vdu_count = "-cnt-" + vdu_count
1247
1248         # Generate a random suffix with 5 characters (the default size used by K8s)
1249         random_suffix = generate_random_alfanum_string(size=5)
1250
1251         application_name = "app-{}{}{}-{}".format(
1252             vnf_id, vdu_id, vdu_count, random_suffix
1253         )
1254         return application_name
1255
1256     @staticmethod
1257     def _get_vca_record(search_key: str, vca_records: list, vdu_id: str) -> dict:
1258         """Get the correct VCA record dict depending on the search key
1259
1260         Args:
1261             search_key  (str):      keyword to find the correct VCA record
1262             vca_records (list):     All VCA records as list
1263             vdu_id  (str):          VDU ID
1264
1265         Returns:
1266             vca_record  (dict):     Dictionary which includes the correct VCA record
1267
1268         """
1269         return next(
1270             filter(lambda record: record[search_key] == vdu_id, vca_records), {}
1271         )
1272
1273     @staticmethod
1274     def _generate_application_name(
1275         charm_level: str,
1276         vnfrs: dict,
1277         vca_records: list,
1278         vnf_count: str = None,
1279         vdu_id: str = None,
1280         vdu_count: str = None,
1281     ) -> str:
1282         """Generate application name to make the relevant charm of VDU/KDU
1283         in the VNFD descriptor become clearly visible.
1284         Limiting the app name to 50 characters.
1285
1286         Args:
1287             charm_level  (str):  level of charm
1288             vnfrs  (dict):  vnf record dict
1289             vca_records   (list):   db_nsr["_admin"]["deployed"]["VCA"] as list
1290             vnf_count   (str): vnf count index
1291             vdu_id   (str):  VDU ID
1292             vdu_count   (str):  vdu count index
1293
1294         Returns:
1295             application_name (str): generated application name
1296
1297         """
1298         application_name = ""
1299         if charm_level == "ns-level":
1300             if len(vca_records) != 1:
1301                 raise N2VCException(message="One VCA record is expected.")
1302             # Only one VCA record is expected if it's ns-level charm.
1303             # Shorten the charm name to its first 40 characters.
1304             charm_name = vca_records[0]["charm_name"][:40]
1305             if not charm_name:
1306                 raise N2VCException(message="Charm name should be provided.")
1307             application_name = charm_name + "-ns"
1308
1309         elif charm_level == "vnf-level":
1310             if len(vca_records) < 1:
1311                 raise N2VCException(message="One or more VCA record is expected.")
1312             # If VNF is scaled, more than one VCA record may be included in vca_records
1313             # but ee_descriptor_id is same.
1314             # Shorten the ee_descriptor_id and member-vnf-index-ref
1315             # to first 12 characters.
1316             application_name = (
1317                 vca_records[0]["ee_descriptor_id"][:12]
1318                 + "-"
1319                 + vnf_count
1320                 + "-"
1321                 + vnfrs["member-vnf-index-ref"][:12]
1322                 + "-vnf"
1323             )
1324         elif charm_level == "vdu-level":
1325             if len(vca_records) < 1:
1326                 raise N2VCException(message="One or more VCA record is expected.")
1327
1328             # Charms are also used for deployments with Helm charts.
1329             # If deployment unit is a Helm chart/KDU,
1330             # vdu_profile_id and vdu_count will be empty string.
1331             if vdu_count is None:
1332                 vdu_count = ""
1333
1334             # If vnf/vdu is scaled, more than one VCA record may be included in vca_records
1335             # but ee_descriptor_id is same.
1336             # Shorten the ee_descriptor_id, member-vnf-index-ref and vdu_profile_id
1337             # to first 12 characters.
1338             if not vdu_id:
1339                 raise N2VCException(message="vdu-id should be provided.")
1340
1341             vca_record = N2VCJujuConnector._get_vca_record(
1342                 "vdu_id", vca_records, vdu_id
1343             )
1344
1345             if not vca_record:
1346                 vca_record = N2VCJujuConnector._get_vca_record(
1347                     "kdu_name", vca_records, vdu_id
1348                 )
1349
1350             application_name = (
1351                 vca_record["ee_descriptor_id"][:12]
1352                 + "-"
1353                 + vnf_count
1354                 + "-"
1355                 + vnfrs["member-vnf-index-ref"][:12]
1356                 + "-"
1357                 + vdu_id[:12]
1358                 + "-"
1359                 + vdu_count
1360                 + "-vdu"
1361             )
1362
1363         return application_name
1364
1365     def _get_vnf_count_and_record(
1366         self, charm_level: str, vnf_id_and_count: str
1367     ) -> Tuple[str, dict]:
1368         """Get the vnf count and VNF record depend on charm level
1369
1370         Args:
1371             charm_level  (str)
1372             vnf_id_and_count (str)
1373
1374         Returns:
1375             (vnf_count  (str), db_vnfr(dict)) as Tuple
1376
1377         """
1378         vnf_count = ""
1379         db_vnfr = {}
1380
1381         if charm_level in ("vnf-level", "vdu-level"):
1382             vnf_id = "-".join(vnf_id_and_count.split("-")[:-1])
1383             vnf_count = vnf_id_and_count.split("-")[-1]
1384             db_vnfr = self.db.get_one("vnfrs", {"_id": vnf_id})
1385
1386         # If the charm is ns level, it returns empty vnf_count and db_vnfr
1387         return vnf_count, db_vnfr
1388
1389     @staticmethod
1390     def _get_vca_records(charm_level: str, db_nsr: dict, db_vnfr: dict) -> list:
1391         """Get the VCA records from db_nsr dict
1392
1393         Args:
1394             charm_level (str):  level of charm
1395             db_nsr  (dict):     NS record from database
1396             db_vnfr (dict):     VNF record from database
1397
1398         Returns:
1399             vca_records (list):  List of VCA record dictionaries
1400
1401         """
1402         vca_records = {}
1403         if charm_level == "ns-level":
1404             vca_records = list(
1405                 filter(
1406                     lambda vca_record: vca_record["target_element"] == "ns",
1407                     db_nsr["_admin"]["deployed"]["VCA"],
1408                 )
1409             )
1410         elif charm_level in ["vnf-level", "vdu-level"]:
1411             vca_records = list(
1412                 filter(
1413                     lambda vca_record: vca_record["member-vnf-index"]
1414                     == db_vnfr["member-vnf-index-ref"],
1415                     db_nsr["_admin"]["deployed"]["VCA"],
1416                 )
1417             )
1418
1419         return vca_records
1420
1421     def _get_application_name(self, namespace: str) -> str:
1422         """Build application name from namespace
1423
1424         Application name structure:
1425             NS level: <charm-name>-ns
1426             VNF level: <ee-name>-z<vnf-ordinal-scale-number>-<vnf-profile-id>-vnf
1427             VDU level: <ee-name>-z<vnf-ordinal-scale-number>-<vnf-profile-id>-
1428             <vdu-profile-id>-z<vdu-ordinal-scale-number>-vdu
1429
1430         Application naming for backward compatibility (old structure):
1431             NS level: app-<random_value>
1432             VNF level: app-vnf-<vnf-id>-z<ordinal-scale-number>-<random_value>
1433             VDU level: app-vnf-<vnf-id>-z<vnf-ordinal-scale-number>-vdu-
1434             <vdu-id>-cnt-<vdu-count>-z<vdu-ordinal-scale-number>-<random_value>
1435
1436         Args:
1437             namespace   (str)
1438
1439         Returns:
1440             application_name    (str)
1441
1442         """
1443         # split namespace components
1444         (
1445             nsi_id,
1446             ns_id,
1447             vnf_id_and_count,
1448             vdu_id,
1449             vdu_count,
1450         ) = self._get_namespace_components(namespace=namespace)
1451
1452         if not ns_id:
1453             raise N2VCException(message="ns-id should be provided.")
1454
1455         charm_level = self._find_charm_level(vnf_id_and_count, vdu_id)
1456         db_nsr = self.db.get_one("nsrs", {"_id": ns_id})
1457         vnf_count, db_vnfr = self._get_vnf_count_and_record(
1458             charm_level, vnf_id_and_count
1459         )
1460         vca_records = self._get_vca_records(charm_level, db_nsr, db_vnfr)
1461
1462         if all("charm_name" in vca_record.keys() for vca_record in vca_records):
1463             application_name = self._generate_application_name(
1464                 charm_level,
1465                 db_vnfr,
1466                 vca_records,
1467                 vnf_count=vnf_count,
1468                 vdu_id=vdu_id,
1469                 vdu_count=vdu_count,
1470             )
1471         else:
1472             application_name = self._generate_backward_compatible_application_name(
1473                 vnf_id_and_count, vdu_id, vdu_count
1474             )
1475
1476         return N2VCJujuConnector._format_app_name(application_name)
1477
1478     @staticmethod
1479     def _format_model_name(name: str) -> str:
1480         """Format the name of the model.
1481
1482         Model names may only contain lowercase letters, digits and hyphens
1483         """
1484
1485         return name.replace("_", "-").replace(" ", "-").lower()
1486
1487     @staticmethod
1488     def _format_app_name(name: str) -> str:
1489         """Format the name of the application (in order to assure valid application name).
1490
1491         Application names have restrictions (run juju deploy --help):
1492             - contains lowercase letters 'a'-'z'
1493             - contains numbers '0'-'9'
1494             - contains hyphens '-'
1495             - starts with a lowercase letter
1496             - not two or more consecutive hyphens
1497             - after a hyphen, not a group with all numbers
1498         """
1499
1500         def all_numbers(s: str) -> bool:
1501             for c in s:
1502                 if not c.isdigit():
1503                     return False
1504             return True
1505
1506         new_name = name.replace("_", "-")
1507         new_name = new_name.replace(" ", "-")
1508         new_name = new_name.lower()
1509         while new_name.find("--") >= 0:
1510             new_name = new_name.replace("--", "-")
1511         groups = new_name.split("-")
1512
1513         # find 'all numbers' groups and prefix them with a letter
1514         app_name = ""
1515         for i in range(len(groups)):
1516             group = groups[i]
1517             if all_numbers(group):
1518                 group = "z" + group
1519             if i > 0:
1520                 app_name += "-"
1521             app_name += group
1522
1523         if app_name[0].isdigit():
1524             app_name = "z" + app_name
1525
1526         return app_name
1527
1528     async def validate_vca(self, vca_id: str):
1529         """
1530         Validate a VCA by connecting/disconnecting to/from it
1531
1532         :param: vca_id: VCA ID
1533         """
1534         vca_connection = await get_connection(self._store, vca_id=vca_id)
1535         libjuju = Libjuju(vca_connection, log=self.log, n2vc=self)
1536         controller = await libjuju.get_controller()
1537         await libjuju.disconnect_controller(controller)