Catch exceptions when using AsyncioTelnetServer. Fixes #1321.

gns3server/compute/base_node.py

@@ -346,6 +346,7 @@ class BaseNode:
             remaining_trial -= 1
         yield from AsyncioTelnetServer.write_client_intro(writer, echo=True)
         server = AsyncioTelnetServer(reader=reader, writer=writer, binary=True, echo=True)
+        # warning: this will raise OSError exception if there is a problem...
         self._wrapper_telnet_server = yield from asyncio.start_server(server.run, self._manager.port_manager.console_host, self.console)
 
     @property

gns3server/compute/docker/docker_vm.py

@@ -412,7 +412,10 @@ class DockerVM(BaseNode):
             stderr=asyncio.subprocess.STDOUT,
             stdin=asyncio.subprocess.PIPE)
         server = AsyncioTelnetServer(reader=process.stdout, writer=process.stdin, binary=True, echo=True)
+        try:
             self._telnet_servers.append((yield from asyncio.start_server(server.run, self._manager.port_manager.console_host, self.aux)))
+        except OSError as e:
+            raise DockerError("Could not start Telnet server on socket {}:{}: {}".format(self._manager.port_manager.console_host, self.aux, e))
         log.debug("Docker container '%s' started listen for auxilary telnet on %d", self.name, self.aux)
 
     @asyncio.coroutine
@@ -508,7 +511,10 @@ class DockerVM(BaseNode):
         input_stream = InputStream()
 
         telnet = AsyncioTelnetServer(reader=output_stream, writer=input_stream, echo=True)
+        try:
             self._telnet_servers.append((yield from asyncio.start_server(telnet.run, self._manager.port_manager.console_host, self.console)))
+        except OSError as e:
+            raise DockerError("Could not start Telnet server on socket {}:{}: {}".format(self._manager.port_manager.console_host, self.console, e))
 
         self._console_websocket = yield from self.manager.websocket_query("containers/{}/attach/ws?stream=1&stdin=1&stdout=1&stderr=1".format(self._cid))
         input_stream.ws = self._console_websocket

gns3server/compute/dynamips/nodes/ethernet_switch.py

@@ -167,8 +167,10 @@ class EthernetSwitch(Device):
         self._telnet_shell = EthernetSwitchConsole(self)
         self._telnet_shell.prompt = self._name + '> '
         self._telnet = create_telnet_shell(self._telnet_shell)
+        try:
             self._telnet_server = (yield from asyncio.start_server(self._telnet.run, self._manager.port_manager.console_host, self.console))
-
+        except OSError as e:
+            self.project.emit("log.warning", {"message": "Could not start Telnet server on socket {}:{}: {}".format(self._manager.port_manager.console_host, self.console, e)})
         self._hypervisor.devices.append(self)
 
     @asyncio.coroutine

gns3server/compute/iou/iou_vm.py

@@ -541,7 +541,11 @@ class IOUVM(BaseNode):
                 raise IOUError("Could not start IOU {}: {}\n{}".format(self._path, e, iou_stdout))
 
             server = AsyncioTelnetServer(reader=self._iou_process.stdout, writer=self._iou_process.stdin, binary=True, echo=True)
+            try:
                 self._telnet_server = yield from asyncio.start_server(server.run, self._manager.port_manager.console_host, self.console)
+            except OSError as e:
+                yield from self.stop()
+                raise IOUError("Could not start Telnet server on socket {}:{}: {}".format(self._manager.port_manager.console_host, self.console, e))
 
             # configure networking support
             yield from self._networking()

gns3server/compute/virtualbox/virtualbox_vm.py

@@ -942,7 +942,10 @@ class VirtualBoxVM(BaseNode):
                                      writer=self._remote_pipe,
                                      binary=True,
                                      echo=True)
+        try:
             self._telnet_server = yield from asyncio.start_server(server.run, self._manager.port_manager.console_host, self.console)
+        except OSError as e:
+            self.project.emit("log.warning", {"message": "Could not start Telnet server on socket {}:{}: {}".format(self._manager.port_manager.console_host, self.console, e)})
 
     @asyncio.coroutine
     def _stop_remote_console(self):

gns3server/compute/vmware/vmware_vm.py

@@ -848,7 +848,10 @@ class VMwareVM(BaseNode):
                                      writer=self._remote_pipe,
                                      binary=True,
                                      echo=True)
+        try:
             self._telnet_server = yield from asyncio.start_server(server.run, self._manager.port_manager.console_host, self.console)
+        except OSError as e:
+            self.project.emit("log.warning", {"message": "Could not start Telnet server on socket {}:{}: {}".format(self._manager.port_manager.console_host, self.console, e)})
 
     @asyncio.coroutine
     def _stop_remote_console(self):