[CORD-2045] move files from 3.0 to 4.1; include copyright

Change-Id: Ie9675d198be1b36aea818935b8f264e7f5da7ffa
(cherry picked from commit 786c4c5b11171289cbfbb6f5b12586840aef206b)
diff --git a/xos/models.py b/xos/models.py
new file mode 100644
index 0000000..3f2b522
--- /dev/null
+++ b/xos/models.py
@@ -0,0 +1,96 @@
+# Copyright 2017-present Open Networking Foundation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from core.models.plcorebase import *
+from models_decl import VHSSService_decl
+from models_decl import VHSSVendor_decl
+from models_decl import VHSSTenant_decl
+
+from django.db import models
+from core.models import Service, PlCoreBase, Slice, Instance, Tenant, TenantWithContainer, Node, Image, User, Flavor, NetworkParameter, NetworkParameterType, Port, AddressPool
+from core.models.plcorebase import StrippedCharField
+import os
+from django.db import models, transaction
+from django.forms.models import model_to_dict
+from django.db.models import *
+from operator import itemgetter, attrgetter, methodcaller
+from core.models import Tag
+from core.models.service import LeastLoadedNodeScheduler
+import traceback
+from xos.exceptions import *
+from xos.config import Config
+
+class VHSSService(VHSSService_decl):
+   class Meta:
+        proxy = True 
+
+   def create_tenant(self, **kwargs):
+       t = VHSSTenant(kind="vEPC", provider_service=self, connect_method="na", **kwargs)
+       t.save()
+       return t
+
+class VHSSVendor(VHSSVendor_decl):
+   class Meta:
+       proxy = True
+
+class VHSSTenant(VHSSTenant_decl):
+   class Meta:
+        proxy = True 
+
+   def __init__(self, *args, **kwargs):
+       vhssservice = VHSSService.get_service_objects().all()
+       if vhssservice:
+           self._meta.get_field(
+                   "provider_service").default = vhssservice[0].id
+       super(VHSSTenant, self).__init__(*args, **kwargs)
+
+   @property
+   def image(self):
+       if not self.vhss_vendor:
+           return super(VHSSTenant, self).image
+       return self.vhss_vendor.image
+   
+   def save_instance(self, instance):
+       if self.vhss_vendor:
+           instance.flavor = self.vhss_vendor.flavor
+       super(VHSSTenant, self).save_instance(instance)
+
+   def save(self, *args, **kwargs):
+       if not self.creator:
+           if not getattr(self, "caller", None):
+               raise XOSProgrammingError("VHSSTenant's self.caller was not set")
+           self.creator = self.caller
+           if not self.creator:
+               raise XOSProgrammingError("VHSSTenant's self.creator was not set")
+
+       super(VHSSTenant, self).save(*args, **kwargs)
+       # This call needs to happen so that an instance is created for this
+       # tenant is created in the slice. One instance is created per tenant.
+       model_policy_vhsstenant(self.pk)
+
+   def delete(self, *args, **kwargs):
+       # Delete the instance that was created for this tenant
+       self.cleanup_container()
+       super(VHSSTenant, self).delete(*args, **kwargs)
+
+def model_policy_vhsstenant(pk):
+    # This section of code is atomic to prevent race conditions
+    with transaction.atomic():
+        # We find all of the tenants that are waiting to update
+        tenant = VHSSTenant.objects.select_for_update().filter(pk=pk)
+        if not tenant:
+            return
+        # Since this code is atomic it is safe to always use the first tenant
+        tenant = tenant[0]
+        tenant.manage_container()