%guest-cid% variable implementation for Qemu VMs. Fixes https://github.com/GNS3/gns3-gui/issues/2804

gns3server/compute/qemu/__init__.py

@@ -30,6 +30,7 @@ from ...utils.asyncio import subprocess_check_output
 from ..base_manager import BaseManager
 from .qemu_error import QemuError
 from .qemu_vm import QemuVM
+from .utils.guest_cid import get_next_guest_cid
 
 import logging
 log = logging.getLogger(__name__)
@@ -40,6 +41,26 @@ class Qemu(BaseManager):
     _NODE_CLASS = QemuVM
     _NODE_TYPE = "qemu"
 
+    def __init__(self):
+
+        super().__init__()
+        self._guest_cid_lock = asyncio.Lock()
+
+    async def create_node(self, *args, **kwargs):
+        """
+        Creates a new Qemu VM.
+
+        :returns: QemuVM instance
+        """
+
+        async with self._guest_cid_lock:
+            # wait for a node to be completely created before adding a new one
+            # this is important otherwise we allocate the same application ID
+            # when creating multiple Qemu VMs at the same time
+            guest_cid = get_next_guest_cid(self.nodes)
+            node = await super().create_node(*args, guest_cid=guest_cid, **kwargs)
+        return node
+
     @staticmethod
     async def get_kvm_archs():
         """

gns3server/compute/qemu/qemu_vm.py

@@ -36,6 +36,7 @@ import json
 from gns3server.utils import parse_version
 from gns3server.utils.asyncio import subprocess_check_output, cancellable_wait_run_in_executor
 from .qemu_error import QemuError
+from .utils.qcow2 import Qcow2, Qcow2Error
 from ..adapters.ethernet_adapter import EthernetAdapter
 from ..nios.nio_udp import NIOUDP
 from ..nios.nio_tap import NIOTAP
@@ -43,7 +44,6 @@ from ..base_node import BaseNode
 from ...schemas.qemu import QEMU_OBJECT_SCHEMA, QEMU_PLATFORMS
 from ...utils.asyncio import monitor_process
 from ...utils.images import md5sum
-from .qcow2 import Qcow2, Qcow2Error
 from ...utils import macaddress_to_int, int_to_macaddress
 
 
@@ -67,7 +67,7 @@ class QemuVM(BaseNode):
     :param platform: Platform to emulate
     """
 
-    def __init__(self, name, node_id, project, manager, linked_clone=True, qemu_path=None, console=None, console_type="telnet", platform=None):
+    def __init__(self, name, node_id, project, manager, guest_cid=None, linked_clone=True, qemu_path=None, console=None, console_type="telnet", platform=None):
 
         super().__init__(name, node_id, project, manager, console=console, console_type=console_type, linked_clone=linked_clone, wrap_console=True)
         server_config = manager.config.get_section_config("Server")
@@ -80,6 +80,7 @@ class QemuVM(BaseNode):
         self._qemu_img_stdout_file = ""
         self._execute_lock = asyncio.Lock()
         self._local_udp_tunnels = {}
+        self._guest_cid = guest_cid
 
         # QEMU VM settings
         if qemu_path:
@@ -124,6 +125,16 @@ class QemuVM(BaseNode):
         self.adapters = 1  # creates 1 adapter by default
         log.info('QEMU VM "{name}" [{id}] has been created'.format(name=self._name, id=self._id))
 
+    @property
+    def guest_cid(self):
+        """
+        Returns guest_cid (console ID) which unique identifier between 3 and 65535
+
+        :returns: integer between 3 and 65535
+        """
+
+        return self._guest_cid
+
     @property
     def monitor(self):
         """
@@ -1917,7 +1928,8 @@ class QemuVM(BaseNode):
         additional_options = additional_options.replace("%vm-id%", self._id)
         additional_options = additional_options.replace("%project-id%", self.project.id)
         additional_options = additional_options.replace("%project-path%", '"' + self.project.path.replace('"', '\\"') + '"')
-        if self._console:
+        additional_options = additional_options.replace("%guest-cid%", str(self._guest_cid))
+        if self._console_type != "none" and self._console:
             additional_options = additional_options.replace("%console-port%", str(self._console))
         command = [self.qemu_path]
         command.extend(["-name", self._name])

gns3server/compute/qemu/utils/guest_cid.py

@@ -0,0 +1,38 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2017 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/>.
+
+from ..qemu_error import QemuError
+
+import logging
+log = logging.getLogger(__name__)
+
+
+def get_next_guest_cid(nodes):
+    """
+    Calculates free guest_id from given nodes
+
+    :param nodes:
+    :raises QemuError when exceeds number
+    :return: integer first free cid
+    """
+
+    used = set([n.guest_cid for n in nodes])
+    pool = set(range(3, 65535))
+    try:
+        return (pool - used).pop()
+    except KeyError:
+        raise QemuError("Cannot create a new Qemu VM (limit of 65535 guest ID on one host reached)")

tests/compute/qemu/test_qcow2.py

@@ -20,7 +20,7 @@ import pytest
 import shutil
 import asyncio
 
-from gns3server.compute.qemu.qcow2 import Qcow2, Qcow2Error
+from gns3server.compute.qemu.utils.qcow2 import Qcow2, Qcow2Error
 
 
 def qemu_img():