Update changelog for 0.4.0

[osm/N2VC.git] / juju / client / connection.py

diff --git a/juju/client/connection.py b/juju/client/connection.py
index 3e304c1..4a9766d 100644 (file)
--- a/juju/client/connection.py
+++ b/juju/client/connection.py
@@ -11,14 +11,95 @@ import subprocess
 import websockets
 from http.client import HTTPSConnection
 
 import websockets
 from http.client import HTTPSConnection
 

+import asyncio

 import yaml
 
 from juju import tag
 import yaml
 
 from juju import tag

-from juju.errors import JujuAPIError, JujuConnectionError
+from juju.client import client
+from juju.client.version_map import VERSION_MAP
+from juju.errors import JujuError, JujuAPIError, JujuConnectionError
+from juju.utils import IdQueue

 
 log = logging.getLogger("websocket")
 
 
 
 log = logging.getLogger("websocket")
 
 

+class Monitor:
+    """
+    Monitor helper class for our Connection class.
+
+    Contains a reference to an instantiated Connection, along with a
+    reference to the Connection.receiver Future. Upon inspecttion of
+    these objects, this class determines whether the connection is in
+    an 'error', 'connected' or 'disconnected' state.
+
+    Use this class to stay up to date on the health of a connection,
+    and take appropriate action if the connection errors out due to
+    network issues or other unexpected circumstances.
+
+    """
+    ERROR = 'error'
+    CONNECTED = 'connected'
+    DISCONNECTED = 'disconnected'
+    UNKNOWN = 'unknown'
+
+    def __init__(self, connection):
+        self.connection = connection
+        self.receiver = None
+
+    @property
+    def status(self):
+        """
+        Determine the status of the connection and receiver, and return
+        ERROR, CONNECTED, or DISCONNECTED as appropriate.
+
+        For simplicity, we only consider ourselves to be connected
+        after the Connection class has setup a receiver task. This
+        only happens after the websocket is open, and the connection
+        isn't usable until that receiver has been started.
+
+        """
+
+        # DISCONNECTED: connection not yet open
+        if not self.connection.ws:
+            return self.DISCONNECTED
+        if not self.receiver:
+            return self.DISCONNECTED
+
+        # ERROR: Connection closed (or errored), but we didn't call
+        # connection.close
+        if not self.connection.close_called and self.receiver_exceptions():
+            return self.ERROR
+        if not self.connection.close_called and not self.connection.ws.open:
+            # The check for self.receiver existing above guards against the
+            # case where we're not open because we simply haven't
+            # setup the connection yet.
+            return self.ERROR
+
+        # DISCONNECTED: cleanly disconnected.
+        if self.connection.close_called and not self.connection.ws.open:
+            return self.DISCONNECTED
+
+        # CONNECTED: everything is fine!
+        if self.connection.ws.open:
+            return self.CONNECTED
+
+        # UNKNOWN: We should never hit this state -- if we do,
+        # something went wrong with the logic above, and we do not
+        # know what state the connection is in.
+        return self.UNKNOWN
+
+    def receiver_exceptions(self):
+        """
+        Return exceptions in the receiver, if any.
+
+        """
+        if not self.receiver:
+            return None
+        if not self.receiver.done():
+            return None
+        return self.receiver.exception()
+
+

 class Connection:
     """
     Usage::
 class Connection:
     """
     Usage::


@@ -33,21 +114,27 @@ class Connection:
         # Connect to the currently active model
         client = await Connection.connect_current()
 
         # Connect to the currently active model
         client = await Connection.connect_current()
 

+    Note: Any connection method or constructor can accept an optional `loop`
+    argument to override the default event loop from `asyncio.get_event_loop`.

     """
     def __init__(
             self, endpoint, uuid, username, password, cacert=None,
     """
     def __init__(
             self, endpoint, uuid, username, password, cacert=None,

-            macaroons=None):
+            macaroons=None, loop=None):

         self.endpoint = endpoint
         self.uuid = uuid
         self.username = username
         self.password = password
         self.macaroons = macaroons
         self.cacert = cacert
         self.endpoint = endpoint
         self.uuid = uuid
         self.username = username
         self.password = password
         self.macaroons = macaroons
         self.cacert = cacert

+        self.loop = loop or asyncio.get_event_loop()

 
         self.__request_id__ = 0
         self.addr = None
         self.ws = None
         self.facades = {}
 
         self.__request_id__ = 0
         self.addr = None
         self.ws = None
         self.facades = {}

+        self.messages = IdQueue(loop=self.loop)
+        self.close_called = False
+        self.monitor = Monitor(connection=self)

 
     @property
     def is_open(self):
 
     @property
     def is_open(self):


@@ -67,19 +154,49 @@ class Connection:
 
         kw = dict()
         kw['ssl'] = self._get_ssl(self.cacert)
 
         kw = dict()
         kw['ssl'] = self._get_ssl(self.cacert)

+        kw['loop'] = self.loop

         self.addr = url
         self.ws = await websockets.connect(url, **kw)
         self.addr = url
         self.ws = await websockets.connect(url, **kw)

+        self.monitor.receiver = self.loop.create_task(self.receiver())

         log.info("Driver connected to juju %s", url)
         return self
 
     async def close(self):
         log.info("Driver connected to juju %s", url)
         return self
 
     async def close(self):

+        self.close_called = True

         await self.ws.close()
 
         await self.ws.close()
 

-    async def recv(self):
-        result = await self.ws.recv()
-        if result is not None:
-            result = json.loads(result)
-        return result
+    async def recv(self, request_id):
+        if not self.is_open:
+            raise websockets.exceptions.ConnectionClosed(0, 'websocket closed')
+        return await self.messages.get(request_id)
+
+    async def receiver(self):
+        while self.is_open:
+            try:
+                result = await self.ws.recv()
+                if result is not None:
+                    result = json.loads(result)
+                    await self.messages.put(result['request-id'], result)
+            except Exception as e:
+                await self.messages.put_all(e)
+                if isinstance(e, websockets.ConnectionClosed):
+                    # ConnectionClosed is not really exceptional for us,
+                    # but it may be for any pending message listeners
+                    return
+                raise
+
+    async def pinger(self):
+        '''
+        A Controller can time us out if we are silent for too long. This
+        is especially true in JaaS, which has a fairly strict timeout.
+
+        To prevent timing out, we send a ping every ten seconds.
+
+        '''
+        pinger_facade = client.PingerFacade.from_connection(self)
+        while self.is_open:
+            await pinger_facade.Ping()
+            await asyncio.sleep(10)

 
     async def rpc(self, msg, encoder=None):
         self.__request_id__ += 1
 
     async def rpc(self, msg, encoder=None):
         self.__request_id__ += 1


@@ -90,9 +207,31 @@ class Connection:
             msg['version'] = self.facades[msg['type']]
         outgoing = json.dumps(msg, indent=2, cls=encoder)
         await self.ws.send(outgoing)
             msg['version'] = self.facades[msg['type']]
         outgoing = json.dumps(msg, indent=2, cls=encoder)
         await self.ws.send(outgoing)

-        result = await self.recv()
-        if result and 'error' in result:
+        result = await self.recv(msg['request-id'])
+
+        if not result:
+            return result
+
+        if 'error' in result:
+            # API Error Response

             raise JujuAPIError(result)
             raise JujuAPIError(result)

+
+        if 'response' not in result:
+            # This may never happen
+            return result
+
+        if 'results' in result['response']:
+            # Check for errors in a result list.
+            errors = []
+            for res in result['response']['results']:
+                if res.get('error', {}).get('message'):
+                    errors.append(res['error']['message'])
+            if errors:
+                raise JujuError(errors)
+
+        elif result['response'].get('error', {}).get('message'):
+            raise JujuError(result['response']['error']['message'])
+

         return result
 
     def http_headers(self):
         return result
 
     def http_headers(self):


@@ -153,6 +292,7 @@ class Connection:
             self.password,
             self.cacert,
             self.macaroons,
             self.password,
             self.cacert,
             self.macaroons,

+            self.loop,

         )
 
     async def controller(self):
         )
 
     async def controller(self):


@@ -166,19 +306,21 @@ class Connection:
             self.password,
             self.cacert,
             self.macaroons,
             self.password,
             self.cacert,
             self.macaroons,

+            self.loop,

         )
 
     @classmethod
     async def connect(
             cls, endpoint, uuid, username, password, cacert=None,
         )
 
     @classmethod
     async def connect(
             cls, endpoint, uuid, username, password, cacert=None,

-            macaroons=None):
+            macaroons=None, loop=None):

         """Connect to the websocket.
 
         If uuid is None, the connection will be to the controller. Otherwise it
         will be to the model.
 
         """
         """Connect to the websocket.
 
         If uuid is None, the connection will be to the controller. Otherwise it
         will be to the model.
 
         """

-        client = cls(endpoint, uuid, username, password, cacert, macaroons)
+        client = cls(endpoint, uuid, username, password, cacert, macaroons,
+                     loop)

         await client.open()
 
         redirect_info = await client.redirect_info()
         await client.open()
 
         redirect_info = await client.redirect_info()


@@ -209,20 +351,19 @@ class Connection:
             "Couldn't authenticate to %s", endpoint)
 
     @classmethod
             "Couldn't authenticate to %s", endpoint)
 
     @classmethod

-    async def connect_current(cls):
+    async def connect_current(cls, loop=None):

         """Connect to the currently active model.
 
         """
         jujudata = JujuData()
         controller_name = jujudata.current_controller()
         """Connect to the currently active model.
 
         """
         jujudata = JujuData()
         controller_name = jujudata.current_controller()

-        models = jujudata.models()[controller_name]
-        model_name = models['current-model']
+        model_name = jujudata.current_model()

 
         return await cls.connect_model(
 
         return await cls.connect_model(

-            '{}:{}'.format(controller_name, model_name))
+            '{}:{}'.format(controller_name, model_name), loop)

 
     @classmethod
 
     @classmethod

-    async def connect_current_controller(cls):
+    async def connect_current_controller(cls, loop=None):

         """Connect to the currently active controller.
 
         """
         """Connect to the currently active controller.
 
         """


@@ -231,10 +372,10 @@ class Connection:
         if not controller_name:
             raise JujuConnectionError('No current controller')
 
         if not controller_name:
             raise JujuConnectionError('No current controller')
 

-        return await cls.connect_controller(controller_name)
+        return await cls.connect_controller(controller_name, loop)

 
     @classmethod
 
     @classmethod

-    async def connect_controller(cls, controller_name):
+    async def connect_controller(cls, controller_name, loop=None):

         """Connect to a controller by name.
 
         """
         """Connect to a controller by name.
 
         """


@@ -248,36 +389,60 @@ class Connection:
         macaroons = get_macaroons() if not password else None
 
         return await cls.connect(
         macaroons = get_macaroons() if not password else None
 
         return await cls.connect(

-            endpoint, None, username, password, cacert, macaroons)
+            endpoint, None, username, password, cacert, macaroons, loop)

 
     @classmethod
 
     @classmethod

-    async def connect_model(cls, model):
+    async def connect_model(cls, model, loop=None):

         """Connect to a model by name.
 
         """Connect to a model by name.
 

-        :param str model: <controller>:<model>
+        :param str model: [<controller>:]<model>

 
         """
 
         """

-        controller_name, model_name = model.split(':')
-

         jujudata = JujuData()
         jujudata = JujuData()

+
+        if ':' in model:
+            # explicit controller given
+            controller_name, model_name = model.split(':')
+        else:
+            # use the current controller if one isn't explicitly given
+            controller_name = jujudata.current_controller()
+            model_name = model
+
+        accounts = jujudata.accounts()[controller_name]
+        username = accounts['user']
+        # model name must include a user prefix, so add it if it doesn't
+        if '/' not in model_name:
+            model_name = '{}/{}'.format(username, model_name)
+

         controller = jujudata.controllers()[controller_name]
         endpoint = controller['api-endpoints'][0]
         cacert = controller.get('ca-cert')
         controller = jujudata.controllers()[controller_name]
         endpoint = controller['api-endpoints'][0]
         cacert = controller.get('ca-cert')

-        accounts = jujudata.accounts()[controller_name]
-        username = accounts['user']

         password = accounts.get('password')
         models = jujudata.models()[controller_name]
         password = accounts.get('password')
         models = jujudata.models()[controller_name]

-        model_name = '{}/{}'.format(username, model_name)

         model_uuid = models['models'][model_name]['uuid']
         macaroons = get_macaroons() if not password else None
 
         return await cls.connect(
         model_uuid = models['models'][model_name]['uuid']
         macaroons = get_macaroons() if not password else None
 
         return await cls.connect(

-            endpoint, model_uuid, username, password, cacert, macaroons)
+            endpoint, model_uuid, username, password, cacert, macaroons, loop)

 
 

-    def build_facades(self, info):
+    def build_facades(self, facades):

         self.facades.clear()
         self.facades.clear()

-        for facade in info:
-            self.facades[facade['name']] = facade['versions'][-1]
+        # In order to work around an issue where the juju api is not
+        # returning a complete list of facades, we simply look up the
+        # juju version in a pregenerated map, and use that info to
+        # populate our list of facades.
+
+        # TODO: if a future version of juju fixes this bug, restore
+        # the following code for that version and higher:
+        # for facade in facades:
+        #     self.facades[facade['name']] = facade['versions'][-1]
+        try:
+            self.facades = VERSION_MAP[self.info['server-version']]
+        except KeyError:
+            log.warning("Could not find a set of facades for {}. Using "
+                        "the latest facade set instead".format(
+                            self.info['server-version']))
+            self.facades = VERSION_MAP['latest']

 
     async def login(self, username, password, macaroons=None):
         if macaroons:
 
     async def login(self, username, password, macaroons=None):
         if macaroons:


@@ -298,8 +463,11 @@ class Connection:
                 "macaroons": macaroons or []
             }})
         response = result['response']
                 "macaroons": macaroons or []
             }})
         response = result['response']

-        self.build_facades(response.get('facades', {}))

         self.info = response.copy()
         self.info = response.copy()

+        self.build_facades(response.get('facades', {}))
+        # Create a pinger to keep the connection alive (needed for
+        # JaaS; harmless elsewhere).
+        self.loop.create_task(self.pinger())

         return response
 
     async def redirect_info(self):
         return response
 
     async def redirect_info(self):


@@ -327,6 +495,14 @@ class JujuData:
         output = yaml.safe_load(output)
         return output.get('current-controller', '')
 
         output = yaml.safe_load(output)
         return output.get('current-controller', '')
 

+    def current_model(self, controller_name=None):
+        if not controller_name:
+            controller_name = self.current_controller()
+        models = self.models()[controller_name]
+        if 'current-model' not in models:
+            raise JujuError('No current model')
+        return models['current-model']
+

     def controllers(self):
         return self._load_yaml('controllers.yaml', 'controllers')
 
     def controllers(self):
         return self._load_yaml('controllers.yaml', 'controllers')