Possibility to get the server version over JSON-RPC/Websocket.

gns3server/handlers/jsonrpc_websocket.py

@@ -22,8 +22,9 @@ JSON-RPC protocol over Websockets.
 import zmq
 import uuid
 import tornado.websocket
-from ..version import __version__
 from tornado.escape import json_decode
+from ..version import __version__
+from ..jsonrpc import JSONRPCResponse
 from ..jsonrpc import JSONRPCParseError
 from ..jsonrpc import JSONRPCInvalidRequest
 from ..jsonrpc import JSONRPCMethodNotFound
@@ -52,6 +53,20 @@ class JSONRPCWebSocket(tornado.websocket.WebSocketHandler):
         self._session_id = str(uuid.uuid4())
         self.zmq_router = zmq_router
 
+        # special built-in to return the server version
+        self.register_destination("builtin.version", self._server_version)
+
+    def _server_version(self, request_id, params):
+        """
+        Builtin destination to return the server version.
+
+        :param request_id: JSON-RPC call identifier
+        :param params: JSON-RPC method params (not used here)
+        """
+
+        json_message = {"version": __version__}
+        self.write_message(JSONRPCResponse(json_message, request_id)())
+
     @property
     def session_id(self):
         """
@@ -101,6 +116,10 @@ class JSONRPCWebSocket(tornado.websocket.WebSocketHandler):
         :param module: module string
         """
 
+        if destination.startswith("builtin") and destination in cls.destinations:
+            # ignore new built-in destination registration if already registered
+            return
+
         # Make sure the destination is not already registered
         # by another module for instance
         assert destination not in cls.destinations
@@ -114,8 +133,6 @@ class JSONRPCWebSocket(tornado.websocket.WebSocketHandler):
         """
 
         log.info("Websocket client {} connected".format(self.session_id))
-        # send this server version when a client connects
-        self.write_message({"version": __version__})
         self.clients.add(self)
 
     def on_message(self, message):
@@ -126,7 +143,7 @@ class JSONRPCWebSocket(tornado.websocket.WebSocketHandler):
         """
 
         log.debug("Received Websocket message: {}".format(message))
-        
+
         if self.zmq_router.closed:
             # no need to proceed, the ZeroMQ router has been closed.
             return
@@ -150,9 +167,9 @@ class JSONRPCWebSocket(tornado.websocket.WebSocketHandler):
                 # This is a notification, silently ignore this error...
                 return
 
-        if method.startswith("builtin"):
+        if method.startswith("builtin") and request_id:
             log.info("calling built-in method {}".format(method))
-            self.destinations[method]()
+            self.destinations[method](request_id, request.get("params"))
             return
 
         module = self.destinations[method]

gns3server/server.py

@@ -115,9 +115,6 @@ class Server(object):
         #     instance.start()  # starts the new process
         #=======================================================================
 
-        # special built-in destination to stop the server
-        # JSONRPCWebSocket.register_destination("builtin.stop", self._cleanup)
-
         for module in MODULES:
             instance = module(module.__name__.lower(),
                               "127.0.0.1",  # ZeroMQ server address