n2vc/k8s_juju_conn.py

   1 # Copyright 2019 Canonical Ltd.
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #     http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 #     Unless required by applicable law or agreed to in writing, software
  10 #     distributed under the License is distributed on an "AS IS" BASIS,
  11 #     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 #     See the License for the specific language governing permissions and
  13 #     limitations under the License.
  14
  15 import asyncio
  16 from typing import Union
  17 import os
  18 import uuid
  19 import yaml
  20 import tempfile
  21 import binascii
  22
  23 from n2vc.config import EnvironConfig
  24 from n2vc.exceptions import K8sException
  25 from n2vc.k8s_conn import K8sConnector
  26 from n2vc.kubectl import Kubectl
  27 from .exceptions import MethodNotImplemented
  28 from n2vc.libjuju import Libjuju
  29 from n2vc.utils import obj_to_dict, obj_to_yaml
  30 from n2vc.store import MotorStore
  31 from n2vc.vca.cloud import Cloud
  32 from n2vc.vca.connection import get_connection
  33
  34
  35 RBAC_LABEL_KEY_NAME = "rbac-id"
  36 RBAC_STACK_PREFIX = "juju-credential"
  37
  38
  39 def generate_rbac_id():
  40     return binascii.hexlify(os.urandom(4)).decode()
  41
  42
  43 class K8sJujuConnector(K8sConnector):
  44     libjuju = None
  45
  46     def __init__(
  47         self,
  48         fs: object,
  49         db: object,
  50         kubectl_command: str = "/usr/bin/kubectl",
  51         juju_command: str = "/usr/bin/juju",
  52         log: object = None,
  53         loop: object = None,
  54         on_update_db=None,
  55     ):
  56         """
  57         :param fs: file system for kubernetes and helm configuration
  58         :param db: Database object
  59         :param kubectl_command: path to kubectl executable
  60         :param helm_command: path to helm executable
  61         :param log: logger
  62         :param: loop: Asyncio loop
  63         """
  64
  65         # parent class
  66         K8sConnector.__init__(
  67             self,
  68             db,
  69             log=log,
  70             on_update_db=on_update_db,
  71         )
  72
  73         self.fs = fs
  74         self.loop = loop or asyncio.get_event_loop()
  75         self.log.debug("Initializing K8S Juju connector")
  76
  77         db_uri = EnvironConfig(prefixes=["OSMLCM_", "OSMMON_"]).get("database_uri")
  78         self._store = MotorStore(db_uri)
  79         self.loading_libjuju = asyncio.Lock(loop=self.loop)
  80
  81         self.log.debug("K8S Juju connector initialized")
  82         # TODO: Remove these commented lines:
  83         # self.authenticated = False
  84         # self.models = {}
  85         # self.juju_secret = ""
  86
  87     """Initialization"""
  88
  89     async def init_env(
  90         self,
  91         k8s_creds: str,
  92         namespace: str = "kube-system",
  93         reuse_cluster_uuid: str = None,
  94         **kwargs,
  95     ) -> (str, bool):
  96         """
  97         It prepares a given K8s cluster environment to run Juju bundles.
  98
  99         :param k8s_creds: credentials to access a given K8s cluster, i.e. a valid
 100             '.kube/config'
 101         :param namespace: optional namespace to be used for juju. By default,
 102             'kube-system' will be used
 103         :param reuse_cluster_uuid: existing cluster uuid for reuse
 104         :param: kwargs: Additional parameters
 105             vca_id (str): VCA ID
 106
 107         :return: uuid of the K8s cluster and True if connector has installed some
 108             software in the cluster
 109             (on error, an exception will be raised)
 110         """
 111         libjuju = await self._get_libjuju(kwargs.get("vca_id"))
 112
 113         cluster_uuid = reuse_cluster_uuid or str(uuid.uuid4())
 114         kubectl = self._get_kubectl(k8s_creds)
 115
 116         # CREATING RESOURCES IN K8S
 117         rbac_id = generate_rbac_id()
 118         metadata_name = "{}-{}".format(RBAC_STACK_PREFIX, rbac_id)
 119         labels = {RBAC_STACK_PREFIX: rbac_id}
 120
 121         # Create cleanup dictionary to clean up created resources
 122         # if it fails in the middle of the process
 123         cleanup_data = []
 124         try:
 125             kubectl.create_cluster_role(
 126                 name=metadata_name,
 127                 labels=labels,
 128             )
 129             cleanup_data.append(
 130                 {
 131                     "delete": kubectl.delete_cluster_role,
 132                     "args": (metadata_name,),
 133                 }
 134             )
 135
 136             kubectl.create_service_account(
 137                 name=metadata_name,
 138                 labels=labels,
 139             )
 140             cleanup_data.append(
 141                 {
 142                     "delete": kubectl.delete_service_account,
 143                     "args": (metadata_name,),
 144                 }
 145             )
 146
 147             kubectl.create_cluster_role_binding(
 148                 name=metadata_name,
 149                 labels=labels,
 150             )
 151             cleanup_data.append(
 152                 {
 153                     "delete": kubectl.delete_service_account,
 154                     "args": (metadata_name,),
 155                 }
 156             )
 157             token, client_cert_data = await kubectl.get_secret_data(
 158                 metadata_name,
 159             )
 160
 161             default_storage_class = kubectl.get_default_storage_class()
 162             await libjuju.add_k8s(
 163                 name=cluster_uuid,
 164                 rbac_id=rbac_id,
 165                 token=token,
 166                 client_cert_data=client_cert_data,
 167                 configuration=kubectl.configuration,
 168                 storage_class=default_storage_class,
 169                 credential_name=self._get_credential_name(cluster_uuid),
 170             )
 171             return cluster_uuid, True
 172         except Exception as e:
 173             self.log.error("Error initializing k8scluster: {}".format(e))
 174             if len(cleanup_data) > 0:
 175                 self.log.debug("Cleaning up created resources in k8s cluster...")
 176                 for item in cleanup_data:
 177                     delete_function = item["delete"]
 178                     delete_args = item["args"]
 179                     delete_function(*delete_args)
 180                 self.log.debug("Cleanup finished")
 181             raise e
 182
 183     """Repo Management"""
 184
 185     async def repo_add(
 186         self,
 187         name: str,
 188         url: str,
 189         _type: str = "charm",
 190     ):
 191         raise MethodNotImplemented()
 192
 193     async def repo_list(self):
 194         raise MethodNotImplemented()
 195
 196     async def repo_remove(
 197         self,
 198         name: str,
 199     ):
 200         raise MethodNotImplemented()
 201
 202     async def synchronize_repos(self, cluster_uuid: str, name: str):
 203         """
 204         Returns None as currently add_repo is not implemented
 205         """
 206         return None
 207
 208     """Reset"""
 209
 210     async def reset(
 211         self,
 212         cluster_uuid: str,
 213         force: bool = False,
 214         uninstall_sw: bool = False,
 215         **kwargs,
 216     ) -> bool:
 217         """Reset a cluster
 218
 219         Resets the Kubernetes cluster by removing the model that represents it.
 220
 221         :param cluster_uuid str: The UUID of the cluster to reset
 222         :param force: Force reset
 223         :param uninstall_sw: Boolean to uninstall sw
 224         :param: kwargs: Additional parameters
 225             vca_id (str): VCA ID
 226
 227         :return: Returns True if successful or raises an exception.
 228         """
 229
 230         try:
 231             self.log.debug("[reset] Removing k8s cloud")
 232             libjuju = await self._get_libjuju(kwargs.get("vca_id"))
 233
 234             cloud = Cloud(cluster_uuid, self._get_credential_name(cluster_uuid))
 235
 236             cloud_creds = await libjuju.get_cloud_credentials(cloud)
 237
 238             await libjuju.remove_cloud(cluster_uuid)
 239
 240             credentials = self.get_credentials(cluster_uuid=cluster_uuid)
 241
 242             kubectl = self._get_kubectl(credentials)
 243
 244             delete_functions = [
 245                 kubectl.delete_cluster_role_binding,
 246                 kubectl.delete_service_account,
 247                 kubectl.delete_cluster_role,
 248             ]
 249
 250             credential_attrs = cloud_creds[0].result["attrs"]
 251             if RBAC_LABEL_KEY_NAME in credential_attrs:
 252                 rbac_id = credential_attrs[RBAC_LABEL_KEY_NAME]
 253                 metadata_name = "{}-{}".format(RBAC_STACK_PREFIX, rbac_id)
 254                 for delete_func in delete_functions:
 255                     try:
 256                         delete_func(metadata_name)
 257                     except Exception as e:
 258                         self.log.warning("Cannot remove resource in K8s {}".format(e))
 259
 260         except Exception as e:
 261             self.log.debug("Caught exception during reset: {}".format(e))
 262             raise e
 263         return True
 264
 265     """Deployment"""
 266
 267     async def install(
 268         self,
 269         cluster_uuid: str,
 270         kdu_model: str,
 271         kdu_instance: str,
 272         atomic: bool = True,
 273         timeout: float = 1800,
 274         params: dict = None,
 275         db_dict: dict = None,
 276         kdu_name: str = None,
 277         namespace: str = None,
 278         **kwargs,
 279     ) -> bool:
 280         """Install a bundle
 281
 282         :param cluster_uuid str: The UUID of the cluster to install to
 283         :param kdu_model str: The name or path of a bundle to install
 284         :param kdu_instance: Kdu instance name
 285         :param atomic bool: If set, waits until the model is active and resets
 286                             the cluster on failure.
 287         :param timeout int: The time, in seconds, to wait for the install
 288                             to finish
 289         :param params dict: Key-value pairs of instantiation parameters
 290         :param kdu_name: Name of the KDU instance to be installed
 291         :param namespace: K8s namespace to use for the KDU instance
 292         :param kwargs: Additional parameters
 293             vca_id (str): VCA ID
 294
 295         :return: If successful, returns ?
 296         """
 297         libjuju = await self._get_libjuju(kwargs.get("vca_id"))
 298         bundle = kdu_model
 299
 300         if not db_dict:
 301             raise K8sException("db_dict must be set")
 302         if not bundle:
 303             raise K8sException("bundle must be set")
 304
 305         if bundle.startswith("cs:"):
 306             pass
 307         elif bundle.startswith("http"):
 308             # Download the file
 309             pass
 310         else:
 311             new_workdir = kdu_model.strip(kdu_model.split("/")[-1])
 312             os.chdir(new_workdir)
 313             bundle = "local:{}".format(kdu_model)
 314
 315         self.log.debug("Checking for model named {}".format(kdu_instance))
 316
 317         # Create the new model
 318         self.log.debug("Adding model: {}".format(kdu_instance))
 319         cloud = Cloud(cluster_uuid, self._get_credential_name(cluster_uuid))
 320         await libjuju.add_model(kdu_instance, cloud)
 321
 322         # if model:
 323         # TODO: Instantiation parameters
 324
 325         """
 326         "Juju bundle that models the KDU, in any of the following ways:
 327             - <juju-repo>/<juju-bundle>
 328             - <juju-bundle folder under k8s_models folder in the package>
 329             - <juju-bundle tgz file (w/ or w/o extension) under k8s_models folder
 330                 in the package>
 331             - <URL_where_to_fetch_juju_bundle>
 332         """
 333         try:
 334             previous_workdir = os.getcwd()
 335         except FileNotFoundError:
 336             previous_workdir = "/app/storage"
 337
 338         self.log.debug("[install] deploying {}".format(bundle))
 339         await libjuju.deploy(
 340             bundle, model_name=kdu_instance, wait=atomic, timeout=timeout
 341         )
 342         os.chdir(previous_workdir)
 343         if self.on_update_db:
 344             await self.on_update_db(
 345                 cluster_uuid,
 346                 kdu_instance,
 347                 filter=db_dict["filter"],
 348                 vca_id=kwargs.get("vca_id"),
 349             )
 350         return True
 351
 352     async def scale(
 353         self,
 354         kdu_instance: str,
 355         scale: int,
 356         resource_name: str,
 357         total_timeout: float = 1800,
 358         **kwargs,
 359     ) -> bool:
 360         """Scale an application in a model
 361
 362         :param: kdu_instance str:        KDU instance name
 363         :param: scale int:               Scale to which to set this application
 364         :param: resource_name str:       Resource name (Application name)
 365         :param: timeout float:           The time, in seconds, to wait for the install
 366                                          to finish
 367         :param kwargs:                   Additional parameters
 368                                             vca_id (str): VCA ID
 369
 370         :return: If successful, returns True
 371         """
 372
 373         try:
 374             libjuju = await self._get_libjuju(kwargs.get("vca_id"))
 375             await libjuju.scale_application(
 376                 model_name=kdu_instance,
 377                 application_name=resource_name,
 378                 scale=scale,
 379                 total_timeout=total_timeout,
 380             )
 381         except Exception as e:
 382             error_msg = "Error scaling application {} in kdu instance {}: {}".format(
 383                 resource_name, kdu_instance, e
 384             )
 385             self.log.error(error_msg)
 386             raise K8sException(message=error_msg)
 387         return True
 388
 389     async def get_scale_count(
 390         self,
 391         resource_name: str,
 392         kdu_instance: str,
 393         **kwargs,
 394     ) -> int:
 395         """Get an application scale count
 396
 397         :param: resource_name str:       Resource name (Application name)
 398         :param: kdu_instance str:        KDU instance name
 399         :param kwargs:                   Additional parameters
 400                                             vca_id (str): VCA ID
 401         :return: Return application instance count
 402         """
 403         try:
 404             libjuju = await self._get_libjuju(kwargs.get("vca_id"))
 405             status = await libjuju.get_model_status(kdu_instance)
 406             return len(status.applications[resource_name].units)
 407         except Exception as e:
 408             error_msg = "Error getting scale count from application {} in kdu instance {}: {}".format(
 409                 resource_name, kdu_instance, e
 410             )
 411             self.log.error(error_msg)
 412             raise K8sException(message=error_msg)
 413
 414     async def instances_list(self, cluster_uuid: str) -> list:
 415         """
 416         returns a list of deployed releases in a cluster
 417
 418         :param cluster_uuid: the cluster
 419         :return:
 420         """
 421         return []
 422
 423     async def upgrade(
 424         self,
 425         cluster_uuid: str,
 426         kdu_instance: str,
 427         kdu_model: str = None,
 428         params: dict = None,
 429     ) -> str:
 430         """Upgrade a model
 431
 432         :param cluster_uuid str: The UUID of the cluster to upgrade
 433         :param kdu_instance str: The unique name of the KDU instance
 434         :param kdu_model str: The name or path of the bundle to upgrade to
 435         :param params dict: Key-value pairs of instantiation parameters
 436
 437         :return: If successful, reference to the new revision number of the
 438                  KDU instance.
 439         """
 440
 441         # TODO: Loop through the bundle and upgrade each charm individually
 442
 443         """
 444         The API doesn't have a concept of bundle upgrades, because there are
 445         many possible changes: charm revision, disk, number of units, etc.
 446
 447         As such, we are only supporting a limited subset of upgrades. We'll
 448         upgrade the charm revision but leave storage and scale untouched.
 449
 450         Scale changes should happen through OSM constructs, and changes to
 451         storage would require a redeployment of the service, at least in this
 452         initial release.
 453         """
 454         raise MethodNotImplemented()
 455
 456     """Rollback"""
 457
 458     async def rollback(
 459         self,
 460         cluster_uuid: str,
 461         kdu_instance: str,
 462         revision: int = 0,
 463     ) -> str:
 464         """Rollback a model
 465
 466         :param cluster_uuid str: The UUID of the cluster to rollback
 467         :param kdu_instance str: The unique name of the KDU instance
 468         :param revision int: The revision to revert to. If omitted, rolls back
 469                              the previous upgrade.
 470
 471         :return: If successful, returns the revision of active KDU instance,
 472                  or raises an exception
 473         """
 474         raise MethodNotImplemented()
 475
 476     """Deletion"""
 477
 478     async def uninstall(
 479         self,
 480         cluster_uuid: str,
 481         kdu_instance: str,
 482         **kwargs,
 483     ) -> bool:
 484         """Uninstall a KDU instance
 485
 486         :param cluster_uuid str: The UUID of the cluster
 487         :param kdu_instance str: The unique name of the KDU instance
 488         :param kwargs: Additional parameters
 489             vca_id (str): VCA ID
 490
 491         :return: Returns True if successful, or raises an exception
 492         """
 493
 494         self.log.debug("[uninstall] Destroying model")
 495         libjuju = await self._get_libjuju(kwargs.get("vca_id"))
 496
 497         await libjuju.destroy_model(kdu_instance, total_timeout=3600)
 498
 499         # self.log.debug("[uninstall] Model destroyed and disconnecting")
 500         # await controller.disconnect()
 501
 502         return True
 503         # TODO: Remove these commented lines
 504         # if not self.authenticated:
 505         #     self.log.debug("[uninstall] Connecting to controller")
 506         #     await self.login(cluster_uuid)
 507
 508     async def exec_primitive(
 509         self,
 510         cluster_uuid: str = None,
 511         kdu_instance: str = None,
 512         primitive_name: str = None,
 513         timeout: float = 300,
 514         params: dict = None,
 515         db_dict: dict = None,
 516         **kwargs,
 517     ) -> str:
 518         """Exec primitive (Juju action)
 519
 520         :param cluster_uuid str: The UUID of the cluster
 521         :param kdu_instance str: The unique name of the KDU instance
 522         :param primitive_name: Name of action that will be executed
 523         :param timeout: Timeout for action execution
 524         :param params: Dictionary of all the parameters needed for the action
 525         :param db_dict: Dictionary for any additional data
 526         :param kwargs: Additional parameters
 527             vca_id (str): VCA ID
 528
 529         :return: Returns the output of the action
 530         """
 531         libjuju = await self._get_libjuju(kwargs.get("vca_id"))
 532
 533         if not params or "application-name" not in params:
 534             raise K8sException(
 535                 "Missing application-name argument, \
 536                                 argument needed for K8s actions"
 537             )
 538         try:
 539             self.log.debug(
 540                 "[exec_primitive] Getting model "
 541                 "kdu_instance: {}".format(kdu_instance)
 542             )
 543             application_name = params["application-name"]
 544             actions = await libjuju.get_actions(application_name, kdu_instance)
 545             if primitive_name not in actions:
 546                 raise K8sException("Primitive {} not found".format(primitive_name))
 547             output, status = await libjuju.execute_action(
 548                 application_name, kdu_instance, primitive_name, **params
 549             )
 550
 551             if status != "completed":
 552                 raise K8sException(
 553                     "status is not completed: {} output: {}".format(status, output)
 554                 )
 555             if self.on_update_db:
 556                 await self.on_update_db(
 557                     cluster_uuid, kdu_instance, filter=db_dict["filter"]
 558                 )
 559
 560             return output
 561
 562         except Exception as e:
 563             error_msg = "Error executing primitive {}: {}".format(primitive_name, e)
 564             self.log.error(error_msg)
 565             raise K8sException(message=error_msg)
 566
 567     """Introspection"""
 568
 569     async def inspect_kdu(
 570         self,
 571         kdu_model: str,
 572     ) -> dict:
 573         """Inspect a KDU
 574
 575         Inspects a bundle and returns a dictionary of config parameters and
 576         their default values.
 577
 578         :param kdu_model str: The name or path of the bundle to inspect.
 579
 580         :return: If successful, returns a dictionary of available parameters
 581                  and their default values.
 582         """
 583
 584         kdu = {}
 585         if not os.path.exists(kdu_model):
 586             raise K8sException("file {} not found".format(kdu_model))
 587
 588         with open(kdu_model, "r") as f:
 589             bundle = yaml.safe_load(f.read())
 590
 591             """
 592             {
 593                 'description': 'Test bundle',
 594                 'bundle': 'kubernetes',
 595                 'applications': {
 596                     'mariadb-k8s': {
 597                         'charm': 'cs:~charmed-osm/mariadb-k8s-20',
 598                         'scale': 1,
 599                         'options': {
 600                             'password': 'manopw',
 601                             'root_password': 'osm4u',
 602                             'user': 'mano'
 603                         },
 604                         'series': 'kubernetes'
 605                     }
 606                 }
 607             }
 608             """
 609             # TODO: This should be returned in an agreed-upon format
 610             kdu = bundle["applications"]
 611
 612         return kdu
 613
 614     async def help_kdu(
 615         self,
 616         kdu_model: str,
 617     ) -> str:
 618         """View the README
 619
 620         If available, returns the README of the bundle.
 621
 622         :param kdu_model str: The name or path of a bundle
 623
 624         :return: If found, returns the contents of the README.
 625         """
 626         readme = None
 627
 628         files = ["README", "README.txt", "README.md"]
 629         path = os.path.dirname(kdu_model)
 630         for file in os.listdir(path):
 631             if file in files:
 632                 with open(file, "r") as f:
 633                     readme = f.read()
 634                     break
 635
 636         return readme
 637
 638     async def status_kdu(
 639         self,
 640         cluster_uuid: str,
 641         kdu_instance: str,
 642         complete_status: bool = False,
 643         yaml_format: bool = False,
 644         **kwargs,
 645     ) -> Union[str, dict]:
 646         """Get the status of the KDU
 647
 648         Get the current status of the KDU instance.
 649
 650         :param cluster_uuid str: The UUID of the cluster
 651         :param kdu_instance str: The unique id of the KDU instance
 652         :param complete_status: To get the complete_status of the KDU
 653         :param yaml_format: To get the status in proper format for NSR record
 654         :param: kwargs: Additional parameters
 655             vca_id (str): VCA ID
 656
 657         :return: Returns a dictionary containing namespace, state, resources,
 658                  and deployment_time and returns complete_status if complete_status is True
 659         """
 660         libjuju = await self._get_libjuju(kwargs.get("vca_id"))
 661         status = {}
 662
 663         model_status = await libjuju.get_model_status(kdu_instance)
 664
 665         if not complete_status:
 666             for name in model_status.applications:
 667                 application = model_status.applications[name]
 668                 status[name] = {"status": application["status"]["status"]}
 669         else:
 670             if yaml_format:
 671                 return obj_to_yaml(model_status)
 672             else:
 673                 return obj_to_dict(model_status)
 674
 675         return status
 676
 677     async def update_vca_status(self, vcastatus: dict, kdu_instance: str, **kwargs):
 678         """
 679         Add all configs, actions, executed actions of all applications in a model to vcastatus dict
 680
 681         :param vcastatus dict: dict containing vcastatus
 682         :param kdu_instance str: The unique id of the KDU instance
 683         :param: kwargs: Additional parameters
 684             vca_id (str): VCA ID
 685
 686         :return: None
 687         """
 688         libjuju = await self._get_libjuju(kwargs.get("vca_id"))
 689         try:
 690             for model_name in vcastatus:
 691                 # Adding executed actions
 692                 vcastatus[model_name][
 693                     "executedActions"
 694                 ] = await libjuju.get_executed_actions(kdu_instance)
 695
 696                 for application in vcastatus[model_name]["applications"]:
 697                     # Adding application actions
 698                     vcastatus[model_name]["applications"][application][
 699                         "actions"
 700                     ] = await libjuju.get_actions(application, kdu_instance)
 701                     # Adding application configs
 702                     vcastatus[model_name]["applications"][application][
 703                         "configs"
 704                     ] = await libjuju.get_application_configs(kdu_instance, application)
 705
 706         except Exception as e:
 707             self.log.debug("Error in updating vca status: {}".format(str(e)))
 708
 709     async def get_services(
 710         self, cluster_uuid: str, kdu_instance: str, namespace: str
 711     ) -> list:
 712         """Return a list of services of a kdu_instance"""
 713
 714         credentials = self.get_credentials(cluster_uuid=cluster_uuid)
 715         kubectl = self._get_kubectl(credentials)
 716         return kubectl.get_services(
 717             field_selector="metadata.namespace={}".format(kdu_instance)
 718         )
 719
 720     async def get_service(
 721         self, cluster_uuid: str, service_name: str, namespace: str
 722     ) -> object:
 723         """Return data for a specific service inside a namespace"""
 724
 725         credentials = self.get_credentials(cluster_uuid=cluster_uuid)
 726         kubectl = self._get_kubectl(credentials)
 727         return kubectl.get_services(
 728             field_selector="metadata.name={},metadata.namespace={}".format(
 729                 service_name, namespace
 730             )
 731         )[0]
 732
 733     def get_credentials(self, cluster_uuid: str) -> str:
 734         """
 735         Get Cluster Kubeconfig
 736         """
 737         k8scluster = self.db.get_one(
 738             "k8sclusters", q_filter={"_id": cluster_uuid}, fail_on_empty=False
 739         )
 740
 741         self.db.encrypt_decrypt_fields(
 742             k8scluster.get("credentials"),
 743             "decrypt",
 744             ["password", "secret"],
 745             schema_version=k8scluster["schema_version"],
 746             salt=k8scluster["_id"],
 747         )
 748
 749         return yaml.safe_dump(k8scluster.get("credentials"))
 750
 751     def _get_credential_name(self, cluster_uuid: str) -> str:
 752         """
 753         Get credential name for a k8s cloud
 754
 755         We cannot use the cluster_uuid for the credential name directly,
 756         because it cannot start with a number, it must start with a letter.
 757         Therefore, the k8s cloud credential name will be "cred-" followed
 758         by the cluster uuid.
 759
 760         :param: cluster_uuid:   Cluster UUID of the kubernetes cloud (=cloud_name)
 761
 762         :return:                Name to use for the credential name.
 763         """
 764         return "cred-{}".format(cluster_uuid)
 765
 766     def get_namespace(
 767         self,
 768         cluster_uuid: str,
 769     ) -> str:
 770         """Get the namespace UUID
 771         Gets the namespace's unique name
 772
 773         :param cluster_uuid str: The UUID of the cluster
 774         :returns: The namespace UUID, or raises an exception
 775         """
 776         pass
 777
 778     @staticmethod
 779     def generate_kdu_instance_name(**kwargs):
 780         db_dict = kwargs.get("db_dict")
 781         kdu_name = kwargs.get("kdu_name", None)
 782         if kdu_name:
 783             kdu_instance = "{}-{}".format(kdu_name, db_dict["filter"]["_id"])
 784         else:
 785             kdu_instance = db_dict["filter"]["_id"]
 786         return kdu_instance
 787
 788     async def _get_libjuju(self, vca_id: str = None) -> Libjuju:
 789         """
 790         Get libjuju object
 791
 792         :param: vca_id: VCA ID
 793                         If None, get a libjuju object with a Connection to the default VCA
 794                         Else, geta libjuju object with a Connection to the specified VCA
 795         """
 796         if not vca_id:
 797             while self.loading_libjuju.locked():
 798                 await asyncio.sleep(0.1)
 799             if not self.libjuju:
 800                 async with self.loading_libjuju:
 801                     vca_connection = await get_connection(self._store)
 802                     self.libjuju = Libjuju(vca_connection, loop=self.loop, log=self.log)
 803             return self.libjuju
 804         else:
 805             vca_connection = await get_connection(self._store, vca_id)
 806             return Libjuju(
 807                 vca_connection,
 808                 loop=self.loop,
 809                 log=self.log,
 810                 n2vc=self,
 811             )
 812
 813     def _get_kubectl(self, credentials: str) -> Kubectl:
 814         """
 815         Get Kubectl object
 816
 817         :param: kubeconfig_credentials: Kubeconfig credentials
 818         """
 819         kubecfg = tempfile.NamedTemporaryFile()
 820         with open(kubecfg.name, "w") as kubecfg_file:
 821             kubecfg_file.write(credentials)
 822         return Kubectl(config_file=kubecfg.name)