Fix #557 - mac addess collision when running IOU on multiple GNS3 servers

gns3server/compute/iou/iou_vm.py

@@ -86,6 +86,7 @@ class IOUVM(BaseNode):
         self._startup_config = ""
         self._private_config = ""
         self._ram = 256  # Megabytes
+        self._application_id = None
         self._l1_keepalives = False  # used to overcome the always-up Ethernet interfaces (not supported by all IOSes).
 
     def _config(self):
@@ -306,11 +307,6 @@ class IOUVM(BaseNode):
 
         super(IOUVM, IOUVM).name.__set__(self, new_name)
 
-    @property
-    def application_id(self):
-
-        return self._manager.get_application_id(self.id)
-
     @property
     def iourc_content(self):
 
@@ -1065,6 +1061,27 @@ class IOUVM(BaseNode):
         else:
             return None
 
+    @property
+    def application_id(self):
+        """
+        Returns application_id which unique identifier for IOU running script. Value is between 1 and 512.
+        When it's not set returns value from the local manager.
+
+        :returns: integer between 1 and 512
+        """
+        if self._application_id is None:
+            return self._manager.get_application_id(self.id)
+        return self._application_id
+
+    @application_id.setter
+    def application_id(self, application_id):
+        """
+        Sets application_id for IOU.
+
+        :param: integer between 1 and 512
+        """
+        self._application_id = application_id
+
     def extract_configs(self):
         """
         Gets the contents of the config files

gns3server/compute/iou/utils/application_id.py

@@ -0,0 +1,36 @@
+# -*- 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 ..iou_error import IOUError
+
+import logging
+log = logging.getLogger(__name__)
+
+
+def get_next_application_id(nodes):
+    """
+    Calculates free application_id from given nodes
+    :param nodes:
+    :raises IOUError when exceeds number
+    :return: integer first free id
+    """
+    used = set([n.properties.get('application_id') for n in nodes if n.node_type == 'iou'])
+    pool = set(range(1, 512))
+    try:
+        return (pool - used).pop()
+    except KeyError:
+        raise IOUError("Cannot create a new IOU VM (limit of 512 VMs reached)")