The server has now 2 notification streams

* A new one for controller related events (compute, appliance templates etc.)
* The existing one for project related events (links, nodes etc.)

gns3server/handlers/api/controller/notification_handler.py

@@ -0,0 +1,84 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2015 GNS3 Technologies Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import asyncio
+import aiohttp
+from aiohttp.web import WebSocketResponse
+from gns3server.web.route import Route
+from gns3server.controller import Controller
+from gns3server.utils.asyncio import asyncio_ensure_future
+
+
+@asyncio.coroutine
+def process_websocket(ws):
+    """
+    Process ping / pong and close message
+    """
+    try:
+        yield from ws.receive()
+    except aiohttp.WSServerHandshakeError:
+        pass
+
+
+class NotificationHandler:
+
+    @Route.get(
+        r"/notifications",
+        description="Receive notifications about the controller",
+        status_codes={
+            200: "End of stream"
+        })
+    def notification(request, response):
+
+        controller = Controller.instance()
+        response.content_type = "application/json"
+        response.set_status(200)
+        response.enable_chunked_encoding()
+
+        yield from response.prepare(request)
+        with controller.notification.controller_queue() as queue:
+            while True:
+                try:
+                    msg = yield from queue.get_json(5)
+                    response.write(("{}\n".format(msg)).encode("utf-8"))
+                except asyncio.futures.CancelledError:
+                    break
+                yield from response.drain()
+
+    @Route.get(
+        r"/notifications/ws",
+        description="Receive notifications about controller from a Websocket",
+        status_codes={
+            200: "End of stream"
+        })
+    def notification_ws(request, response):
+
+        controller = Controller.instance()
+        ws = aiohttp.web.WebSocketResponse()
+        yield from ws.prepare(request)
+
+        asyncio_ensure_future(process_websocket(ws))
+        with controller.notification.controler_queue() as queue:
+            while True:
+                try:
+                    notification = yield from queue.get_json(5)
+                except asyncio.futures.CancelledError:
+                    break
+                if ws.closed:
+                    break
+                ws.send_str(notification)
+        return ws