--- /dev/null
+# Copyright 2020 Canonical Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import asyncio
+import time
+from juju.client import client
+from n2vc.utils import FinalStatus, EntityType
+from n2vc.exceptions import EntityInvalidException
+from n2vc.n2vc_conn import N2VCConnector
+from juju.model import ModelEntity, Model
+from juju.client.overrides import Delta
+
+import logging
+
+logger = logging.getLogger("__main__")
+
+
+class JujuModelWatcher:
+ @staticmethod
+ async def wait_for(
+ model,
+ entity: ModelEntity,
+ progress_timeout: float = 3600,
+ total_timeout: float = 3600,
+ db_dict: dict = None,
+ n2vc: N2VCConnector = None,
+ ):
+ """
+ Wait for entity to reach its final state.
+
+ :param: model: Model to observe
+ :param: entity: Entity object
+ :param: progress_timeout: Maximum time between two updates in the model
+ :param: total_timeout: Timeout for the entity to be active
+ :param: db_dict: Dictionary with data of the DB to write the updates
+ :param: n2vc: N2VC Connector objector
+
+ :raises: asyncio.TimeoutError when timeout reaches
+ """
+
+ if progress_timeout is None:
+ progress_timeout = 3600.0
+ if total_timeout is None:
+ total_timeout = 3600.0
+
+ entity_type = EntityType.get_entity(type(entity))
+ if entity_type not in FinalStatus:
+ raise EntityInvalidException("Entity type not found")
+
+ # Get final states
+ final_states = FinalStatus[entity_type].status
+ field_to_check = FinalStatus[entity_type].field
+
+ # Coroutine to wait until the entity reaches the final state
+ wait_for_entity = asyncio.ensure_future(
+ asyncio.wait_for(
+ model.block_until(
+ lambda: entity.__getattribute__(field_to_check) in final_states
+ ),
+ timeout=total_timeout,
+ )
+ )
+
+ # Coroutine to watch the model for changes (and write them to DB)
+ watcher = asyncio.ensure_future(
+ JujuModelWatcher.model_watcher(
+ model,
+ entity_id=entity.entity_id,
+ entity_type=entity_type,
+ timeout=progress_timeout,
+ db_dict=db_dict,
+ n2vc=n2vc,
+ )
+ )
+
+ tasks = [wait_for_entity, watcher]
+ try:
+ # Execute tasks, and stop when the first is finished
+ # The watcher task won't never finish (unless it timeouts)
+ await asyncio.wait(tasks, return_when=asyncio.FIRST_COMPLETED)
+ except Exception as e:
+ raise e
+ finally:
+ # Cancel tasks
+ for task in tasks:
+ task.cancel()
+
+ @staticmethod
+ async def model_watcher(
+ model: Model,
+ entity_id: str,
+ entity_type: EntityType,
+ timeout: float,
+ db_dict: dict = None,
+ n2vc: N2VCConnector = None,
+ ):
+ """
+ Observes the changes related to an specific entity in a model
+
+ :param: model: Model to observe
+ :param: entity_id: ID of the entity to be observed
+ :param: entity_type: EntityType (p.e. .APPLICATION, .MACHINE, and .ACTION)
+ :param: timeout: Maximum time between two updates in the model
+ :param: db_dict: Dictionary with data of the DB to write the updates
+ :param: n2vc: N2VC Connector objector
+
+ :raises: asyncio.TimeoutError when timeout reaches
+ """
+
+ allwatcher = client.AllWatcherFacade.from_connection(model.connection())
+
+ # Genenerate array with entity types to listen
+ entity_types = (
+ [entity_type, EntityType.UNIT]
+ if entity_type == EntityType.APPLICATION # TODO: Add .ACTION too
+ else [entity_type]
+ )
+
+ # Get time when it should timeout
+ timeout_end = time.time() + timeout
+
+ while True:
+ change = await allwatcher.Next()
+ for delta in change.deltas:
+ write = False
+ delta_entity = None
+
+ # Get delta EntityType
+ delta_entity = EntityType.get_entity_from_delta(delta.entity)
+
+ if delta_entity in entity_types:
+ # Get entity id
+ if entity_type == EntityType.APPLICATION:
+ id = (
+ delta.data["application"]
+ if delta_entity == EntityType.UNIT
+ else delta.data["name"]
+ )
+ else:
+ id = delta.data["id"]
+
+ # Write if the entity id match
+ write = True if id == entity_id else False
+
+ # Update timeout
+ timeout_end = time.time() + timeout
+ (status, status_message, vca_status) = JujuModelWatcher.get_status(
+ delta, entity_type=delta_entity
+ )
+
+ if write and n2vc is not None and db_dict:
+ # Write status to DB
+ status = n2vc.osm_status(delta_entity, status)
+ await n2vc.write_app_status_to_db(
+ db_dict=db_dict,
+ status=status,
+ detailed_status=status_message,
+ vca_status=vca_status,
+ entity_type=delta_entity.value.__name__.lower(),
+ )
+ # Check if timeout
+ if time.time() > timeout_end:
+ raise asyncio.TimeoutError()
+
+ @staticmethod
+ def get_status(delta: Delta, entity_type: EntityType) -> (str, str, str):
+ """
+ Get status from delta
+
+ :param: delta: Delta generated by the allwatcher
+ :param: entity_type: EntityType (p.e. .APPLICATION, .MACHINE, and .ACTION)
+
+ :return (status, message, vca_status)
+ """
+ if entity_type == EntityType.MACHINE:
+ return (
+ delta.data["agent-status"]["current"],
+ delta.data["instance-status"]["message"],
+ delta.data["instance-status"]["current"],
+ )
+ elif entity_type == EntityType.ACTION:
+ return (
+ delta.data["status"],
+ delta.data["status"],
+ delta.data["status"],
+ )
+ elif entity_type == EntityType.APPLICATION:
+ return (
+ delta.data["status"]["current"],
+ delta.data["status"]["message"],
+ delta.data["status"]["current"],
+ )
+ elif entity_type == EntityType.UNIT:
+ return (
+ delta.data["workload-status"]["current"],
+ delta.data["workload-status"]["message"],
+ delta.data["workload-status"]["current"],
+ )
projects / osm / N2VC.git / blobdiff