X-Git-Url: https://osm.etsi.org/gitweb/?a=blobdiff_plain;f=juju%2Fmodel.py;h=04f343797c0455910fe2ecea118061c4c654060a;hb=a56869a418a68b795817d4f14d4065d11784f09f;hp=9d638cbb19a3eece5773cbb039b4d91bc391afbb;hpb=17b45c65afac23a123e66834f93049a1c7e45201;p=osm%2FN2VC.git

diff --git a/juju/model.py b/juju/model.py
index 9d638cb..04f3437 100644
--- a/juju/model.py
+++ b/juju/model.py
@@ -1,4 +1,223 @@
+import asyncio
+import logging
+from concurrent.futures import CancelledError
+
+from .client import client
+from .client import watcher
+from .client import connection
+from .delta import get_entity_delta
+
+log = logging.getLogger(__name__)
+
+
+class ModelObserver(object):
+    def __call__(self, delta, old, new, model):
+        if old is None and new is not None:
+            type_ = 'add'
+        else:
+            type_ = delta.type
+        handler_name = 'on_{}_{}'.format(delta.entity, type_)
+        method = getattr(self, handler_name, self.on_change)
+        log.debug(
+            'Model changed: %s %s %s',
+            delta.entity, delta.type, delta.get_id())
+        method(delta, old, new, model)
+
+    def on_change(self, delta, old, new, model):
+        pass
+
+
+class ModelEntity(object):
+    """An object in the Model tree"""
+
+    def __init__(self, data, model):
+        """Initialize a new entity
+
+        :param data: dict of data from a watcher delta
+        :param model: The model instance in whose object tree this
+            entity resides
+
+        """
+        self.data = data
+        self.model = model
+        self.connection = model.connection
+
+    def __getattr__(self, name):
+        return self.data[name]
+
+
 class Model(object):
+    def __init__(self, loop=None):
+        """Instantiate a new connected Model.
+
+        :param loop: an asyncio event loop
+
+        """
+        self.loop = loop or asyncio.get_event_loop()
+        self.connection = None
+        self.observers = set()
+        self.state = dict()
+        self._watcher_task = None
+        self._watch_shutdown = asyncio.Event(loop=loop)
+        self._watch_received = asyncio.Event(loop=loop)
+
+    async def connect_current(self):
+        self.connection = await connection.Connection.connect_current()
+        self._watch()
+        await self._watch_received.wait()
+
+    async def disconnect(self):
+        self._stop_watching()
+        if self.connection and self.connection.is_open:
+            await self._watch_shutdown.wait()
+            log.debug('Closing model connection')
+            await asyncio.wait_for(self.connection.close(), None)
+            self.connection = None
+
+    def all_units_idle(self):
+        """Return True if all units are idle.
+
+        """
+        for unit in self.units.values():
+            unit_status = unit.data['agent-status']['current']
+            if unit_status != 'idle':
+                return False
+        return True
+
+    async def reset(self, force=False):
+        for app in self.applications.values():
+            await app.destroy()
+        for machine in self.machines.values():
+            await machine.destroy(force=force)
+
+    async def block_until(self, func):
+        async def _block():
+            while not func():
+                await asyncio.sleep(.1)
+        await asyncio.wait_for(_block(), None)
+
+    @property
+    def applications(self):
+        return self.state.get('application', {})
+
+    @property
+    def machines(self):
+        return self.state.get('machine', {})
+
+    @property
+    def units(self):
+        return self.state.get('unit', {})
+
+    def add_observer(self, callable_):
+        """Register an "on-model-change" callback
+
+        Once a watch is started (Model.watch() is called), ``callable_``
+        will be called each time the model changes. callable_ should
+        accept the following positional arguments:
+
+            delta - An instance of :class:`juju.delta.EntityDelta`
+                containing the raw delta data recv'd from the Juju
+                websocket.
+
+            old_obj - If the delta modifies an existing object in the model,
+                old_obj will be a copy of that object, as it was before the
+                delta was applied. Will be None if the delta creates a new
+                entity in the model.
+
+            new_obj - A copy of the new or updated object, after the delta
+                is applied. Will be None if the delta removes an entity
+                from the model.
+
+            model - The :class:`Model` itself.
+
+        """
+        self.observers.add(callable_)
+
+    def _watch(self):
+        """Start an asynchronous watch against this model.
+
+        See :meth:`add_observer` to register an onchange callback.
+
+        """
+        async def _start_watch():
+            self._watch_shutdown.clear()
+            try:
+                allwatcher = watcher.AllWatcher()
+                self._watch_conn = await self.connection.clone()
+                allwatcher.connect(self._watch_conn)
+                while True:
+                    results = await allwatcher.Next()
+                    for delta in results.deltas:
+                        delta = get_entity_delta(delta)
+                        old_obj, new_obj = self._apply_delta(delta)
+                        self._notify_observers(delta, old_obj, new_obj)
+                    self._watch_received.set()
+            except CancelledError:
+                log.debug('Closing watcher connection')
+                await asyncio.wait_for(self._watch_conn.close(), None)
+                self._watch_shutdown.set()
+                self._watch_conn = None
+
+        log.debug('Starting watcher task')
+        self._watcher_task = self.loop.create_task(_start_watch())
+
+    def _stop_watching(self):
+        """Stop the asynchronous watch against this model.
+
+        """
+        log.debug('Stopping watcher task')
+        if self._watcher_task:
+            self._watcher_task.cancel()
+
+    def _apply_delta(self, delta):
+        """Apply delta to our model state and return the a copy of the
+        affected object as it was before and after the update, e.g.:
+
+            old_obj, new_obj = self._apply_delta(delta)
+
+        old_obj may be None if the delta is for the creation of a new object,
+        e.g. a new application or unit is deployed.
+
+        new_obj may be None if no object was created or updated, or if an
+        object was deleted as a result of the delta being applied.
+
+        """
+        old_obj, new_obj = None, None
+
+        if (delta.entity in self.state and
+                delta.get_id() in self.state[delta.entity]):
+            old_obj = self.state[delta.entity][delta.get_id()]
+            if delta.type == 'remove':
+                del self.state[delta.entity][delta.get_id()]
+                return old_obj, new_obj
+
+        new_obj = self.state.setdefault(delta.entity, {})[delta.get_id()] = (
+            self._create_model_entity(delta))
+
+        return old_obj, new_obj
+
+    def _create_model_entity(self, delta):
+        """Return an object instance representing the entity created or
+        updated by ``delta``
+
+        """
+        entity_class = delta.get_entity_class()
+        return entity_class(delta.data, self)
+
+    def _notify_observers(self, delta, old_obj, new_obj):
+        """Call observing callbacks, notifying them of a change in model state
+
+        :param delta: The raw change from the watcher
+            (:class:`juju.client.overrides.Delta`)
+        :param old_obj: The object in the model that this delta updates.
+            May be None.
+        :param new_obj: The object in the model that is created or updated
+            by applying this delta.
+
+        """
+        for o in self.observers:
+            o(delta, old_obj, new_obj, self)
+
     def add_machine(
             self, spec=None, constraints=None, disks=None, series=None,
             count=1):
@@ -29,14 +248,20 @@ class Model(object):
         pass
     add_machines = add_machine
 
-    def add_relation(self, relation1, relation2):
-        """Add a relation between two services.
+    async def add_relation(self, relation1, relation2):
+        """Add a relation between two applications.
 
-        :param str relation1: '<service>[:<relation_name>]'
-        :param str relation2: '<service>[:<relation_name>]'
+        :param str relation1: '<application>[:<relation_name>]'
+        :param str relation2: '<application>[:<relation_name>]'
 
         """
-        pass
+        app_facade = client.ApplicationFacade()
+        app_facade.connect(self.connection)
+
+        log.debug(
+            'Adding relation %s <-> %s', relation1, relation2)
+
+        return await app_facade.AddRelation([relation1, relation2])
 
     def add_space(self, name, *cidrs):
         """Add a new network space.
@@ -144,10 +369,10 @@ class Model(object):
         """
         pass
 
-    def deploy(
+    async def deploy(
             self, entity_url, service_name=None, bind=None, budget=None,
             channel=None, config=None, constraints=None, force=False,
-            num_units=1, plan=None, resource=None, series=None, storage=None,
+            num_units=1, plan=None, resources=None, series=None, storage=None,
             to=None):
         """Deploy a new service or bundle.
 
@@ -164,7 +389,7 @@ class Model(object):
             an unsupported series
         :param int num_units: Number of units to deploy
         :param str plan: Plan under which to deploy charm
-        :param dict resource: <resource name>:<file path> pairs
+        :param dict resources: <resource name>:<file path> pairs
         :param str series: Series on which to deploy
         :param dict storage: Storage constraints TODO how do these look?
         :param str to: Placement directive, e.g.::
@@ -175,8 +400,56 @@ class Model(object):
 
             If None, a new machine is provisioned.
 
-        """
-        pass
+
+        TODO::
+
+            - entity_url must have a revision; look up latest automatically if
+              not provided by caller
+            - service_name is required; fill this in automatically if not
+              provided by caller
+            - series is required; how do we pick a default?
+
+        """
+        if constraints:
+            constraints = client.Value(**constraints)
+
+        if to:
+            placement = [
+                client.Placement(**p) for p in to
+            ]
+        else:
+            placement = []
+
+        if storage:
+            storage = {
+                k: client.Constraints(**v)
+                for k, v in storage.items()
+            }
+
+        app_facade = client.ApplicationFacade()
+        client_facade = client.ClientFacade()
+        app_facade.connect(self.connection)
+        client_facade.connect(self.connection)
+
+        log.debug(
+            'Deploying %s', entity_url)
+
+        await client_facade.AddCharm(channel, entity_url)
+        app = client.ApplicationDeploy(
+            application=service_name,
+            channel=channel,
+            charm_url=entity_url,
+            config=config,
+            constraints=constraints,
+            endpoint_bindings=bind,
+            num_units=num_units,
+            placement=placement,
+            resources=resources,
+            series=series,
+            storage=storage,
+        )
+
+        return await app_facade.Deploy([app])
 
     def destroy(self):
         """Terminate all machines and resources for this model.