vm: make the employed scheduler a config parameter

circle/circle/settings/base.py

@@ -298,6 +298,8 @@ CRISPY_TEMPLATE_PACK = 'bootstrap3'
 
 # format: id: (name, port, protocol)
 VM_ACCESS_PROTOCOLS = loads(get_env_variable('DJANGO_VM_ACCESS_PROTOCOLS',
-					     '''{"nx": ["nx", 22, "tcp"],
+                                             '''{"nx": ["nx", 22, "tcp"],
                                                  "rdp": ["rdp", 3389, "tcp"],
                                                  "ssh": ["ssh", 22, "tcp"]}'''))
+
+VM_SCHEDULER = 'manager.scheduler'

circle/manager/scheduler.py

-def get_node(instance):
-    ''' Select a node for an hosting an instance
-    based on requirements.
+def get_node(instance, nodes):
+    ''' Select a node for hosting an instance based on its requirements.
     '''
     # Return first Node or None
-    models = __import__('vm.models')
     try:
-        return models.models.Node.objects.all()[0]
+        return nodes[0]
     except:
         return None

circle/vm/models.py

 from datetime import timedelta
-
-import django.conf
+from importlib import import_module
 import logging
+
+import django.conf.settings
 from django.contrib.auth.models import User
 from django.db import models
 from django.db.models.signals import pre_delete
@@ -13,12 +14,13 @@ from netaddr import EUI
 
 from . import tasks
 from firewall.models import Vlan, Host
-from manager import vm_manager, scheduler
+from manager import vm_manager
 from storage.models import Disk
 
 
 logger = logging.getLogger(__name__)
 pwgen = User.objects.make_random_password
+scheduler = import_module(name=django.conf.settings.VM_SCHEDULER)
 ACCESS_PROTOCOLS = django.conf.settings.VM_ACCESS_PROTOCOLS
 ACCESS_METHODS = [(k, ap[0]) for k, ap in ACCESS_PROTOCOLS.iteritems()]
 
@@ -443,7 +445,7 @@ class Instance(BaseResourceConfigModel, TimeStampedModel):
 
         # Schedule
         act.update_state("PENDING")
-        self.node = scheduler.get_node(self)
+        self.node = scheduler.get_node(self, Node.objects.all())
         self.save()
 
         # Create virtual images