starting_point
diff --git a/xos/core/models/service.py.new b/xos/core/models/service.py.new
new file mode 100644
index 0000000..d3b6a7d
--- /dev/null
+++ b/xos/core/models/service.py.new
@@ -0,0 +1,791 @@
+from django.db import models
+from core.models import PlCoreBase,SingletonModel,PlCoreBaseManager
+from core.models.plcorebase import StrippedCharField
+from xos.exceptions import *
+from operator import attrgetter
+import json
+
+COARSE_KIND="coarse"
+
+class AttributeMixin(object):
+    # helper for extracting things from a json-encoded service_specific_attribute
+    def get_attribute(self, name, default=None):
+        if self.service_specific_attribute:
+            attributes = json.loads(self.service_specific_attribute)
+        else:
+            attributes = {}
+        return attributes.get(name, default)
+
+    def set_attribute(self, name, value):
+        if self.service_specific_attribute:
+            attributes = json.loads(self.service_specific_attribute)
+        else:
+            attributes = {}
+        attributes[name]=value
+        self.service_specific_attribute = json.dumps(attributes)
+
+    def get_initial_attribute(self, name, default=None):
+        if self._initial["service_specific_attribute"]:
+            attributes = json.loads(self._initial["service_specific_attribute"])
+        else:
+            attributes = {}
+        return attributes.get(name, default)
+
+    @classmethod
+    def setup_simple_attributes(cls):
+        for (attrname, default) in cls.simple_attributes:
+            setattr(cls, attrname, property(lambda self, attrname=attrname, default=default: self.get_attribute(attrname, default),
+                                            lambda self, value, attrname=attrname: self.set_attribute(attrname, value),
+                                            None,
+                                            attrname))
+
+class Service(PlCoreBase, AttributeMixin):
+    # when subclassing a service, redefine KIND to describe the new service
+    KIND = "generic"
+
+    description = models.TextField(max_length=254,null=True, blank=True,help_text="Description of Service")
+    enabled = models.BooleanField(default=True)
+    kind = StrippedCharField(max_length=30, help_text="Kind of service", default=KIND)
+    name = StrippedCharField(max_length=30, help_text="Service Name")
+    versionNumber = StrippedCharField(max_length=30, help_text="Version of Service Definition")
+    published = models.BooleanField(default=True)
+    view_url = StrippedCharField(blank=True, null=True, max_length=1024)
+    icon_url = StrippedCharField(blank=True, null=True, max_length=1024)
+    public_key = models.TextField(null=True, blank=True, max_length=1024, help_text="Public key string")
+    private_key_fn = StrippedCharField(blank=True, null=True, max_length=1024)
+
+    # Service_specific_attribute and service_specific_id are opaque to XOS
+    service_specific_id = StrippedCharField(max_length=30, blank=True, null=True)
+    service_specific_attribute = models.TextField(blank=True, null=True)
+
+    def __init__(self, *args, **kwargs):
+        # for subclasses, set the default kind appropriately
+        self._meta.get_field("kind").default = self.KIND
+        super(Service, self).__init__(*args, **kwargs)
+
+    @classmethod
+    def get_service_objects(cls):
+        return cls.objects.filter(kind = cls.KIND)
+
+    @classmethod
+    def get_deleted_service_objects(cls):
+        return cls.deleted_objects.filter(kind = cls.KIND)
+
+    @classmethod
+    def get_service_objects_by_user(cls, user):
+        return cls.select_by_user(user).filter(kind = cls.KIND)
+
+    @classmethod
+    def select_by_user(cls, user):
+        if user.is_admin:
+            return cls.objects.all()
+        else:
+            service_ids = [sp.slice.id for sp in ServicePrivilege.objects.filter(user=user)]
+            return cls.objects.filter(id__in=service_ids)
+
+    @property
+    def serviceattribute_dict(self):
+        attrs = {}
+        for attr in self.serviceattributes.all():
+            attrs[attr.name] = attr.value
+        return attrs
+
+    def __unicode__(self): return u'%s' % (self.name)
+
+    def can_update(self, user):
+        return user.can_update_service(self, allow=['admin'])
+
+    def get_scalable_nodes(self, slice, max_per_node=None, exclusive_slices=[]):
+        """
+             Get a list of nodes that can be used to scale up a slice.
+
+                slice - slice to scale up
+                max_per_node - maximum numbers of instances that 'slice' can have on a single node
+                exclusive_slices - list of slices that must have no nodes in common with 'slice'.
+        """
+
+        from core.models import Node, Instance # late import to get around order-of-imports constraint in __init__.py
+
+        nodes = list(Node.objects.all())
+
+        conflicting_instances = Instance.objects.filter(slice__in = exclusive_slices)
+        conflicting_nodes = Node.objects.filter(instances__in = conflicting_instances)
+
+        nodes = [x for x in nodes if x not in conflicting_nodes]
+
+        # If max_per_node is set, then limit the number of instances this slice
+        # can have on a single node.
+        if max_per_node:
+            acceptable_nodes = []
+            for node in nodes:
+                existing_count = node.instances.filter(slice=slice).count()
+                if existing_count < max_per_node:
+                    acceptable_nodes.append(node)
+            nodes = acceptable_nodes
+
+        return nodes
+
+    def pick_node(self, slice, max_per_node=None, exclusive_slices=[]):
+        # Pick the best node to scale up a slice.
+
+        nodes = self.get_scalable_nodes(slice, max_per_node, exclusive_slices)
+        nodes = sorted(nodes, key=lambda node: node.instances.all().count())
+        if not nodes:
+            return None
+        return nodes[0]
+
+    def adjust_scale(self, slice_hint, scale, max_per_node=None, exclusive_slices=[]):
+        from core.models import Instance # late import to get around order-of-imports constraint in __init__.py
+
+        slices = [x for x in self.slices.all() if slice_hint in x.name]
+        for slice in slices:
+            while slice.instances.all().count() > scale:
+                s = slice.instances.all()[0]
+                # print "drop instance", s
+                s.delete()
+
+            while slice.instances.all().count() < scale:
+                node = self.pick_node(slice, max_per_node, exclusive_slices)
+                if not node:
+                    # no more available nodes
+                    break
+
+                image = slice.default_image
+                if not image:
+                    raise XOSConfigurationError("No default_image for slice %s" % slice.name)
+
+                flavor = slice.default_flavor
+                if not flavor:
+                    raise XOSConfigurationError("No default_flavor for slice %s" % slice.name)
+
+                s = Instance(slice=slice,
+                           node=node,
+                           creator=slice.creator,
+                           image=image,
+                           flavor=flavor,
+                           deployment=node.site_deployment.deployment)
+                s.save()
+
+                # print "add instance", s
+
+    def get_vtn_src_nets(self):
+        nets=[]
+        for slice in self.slices.all():
+            for ns in slice.networkslices.all():
+                if not ns.network:
+                    continue
+#                if ns.network.template.access in ["direct", "indirect"]:
+#                    # skip access networks; we want to use the private network
+#                    continue
+                if ns.network.name in ["wan_network", "lan_network"]:
+                    # we don't want to attach to the vCPE's lan or wan network
+                    # we only want to attach to its private network
+                    # TODO: fix hard-coding of network name
+                    continue
+                for cn in ns.network.controllernetworks.all():
+                    if cn.net_id:
+                        net = {"name": ns.network.name, "net_id": cn.net_id}
+                        nets.append(net)
+        return nets
+
+    def get_vtn_nets(self):
+        nets=[]
+        for slice in self.slices.all():
+            for ns in slice.networkslices.all():
+                if not ns.network:
+                    continue
+                if ns.network.template.access not in ["direct", "indirect"]:
+                    # skip anything that's not an access network
+                    continue
+                for cn in ns.network.controllernetworks.all():
+                    if cn.net_id:
+                        net = {"name": ns.network.name, "net_id": cn.net_id}
+                        nets.append(net)
+        return nets
+
+    def get_vtn_dependencies_nets(self):
+        provider_nets = []
+        for tenant in self.subscribed_tenants.all():
+            if tenant.provider_service:
+                for net in tenant.provider_service.get_vtn_nets():
+                    if not net in provider_nets:
+                        provider_nets.append(net)
+        return provider_nets
+
+    def get_vtn_dependencies_ids(self):
+        return [x["net_id"] for x in self.get_vtn_dependencies_nets()]
+
+    def get_vtn_dependencies_names(self):
+        return [x["name"]+"_"+x["net_id"] for x in self.get_vtn_dependencies_nets()]
+
+    def get_vtn_src_ids(self):
+        return [x["net_id"] for x in self.get_vtn_src_nets()]
+
+    def get_vtn_src_names(self):
+        return [x["name"]+"_"+x["net_id"] for x in self.get_vtn_src_nets()]
+
+
+class ServiceAttribute(PlCoreBase):
+    name = models.CharField(help_text="Attribute Name", max_length=128)
+    value = StrippedCharField(help_text="Attribute Value", max_length=1024)
+    service = models.ForeignKey(Service, related_name='serviceattributes', help_text="The Service this attribute is associated with")
+
+class ServiceRole(PlCoreBase):
+    ROLE_CHOICES = (('admin','Admin'),)
+    role = StrippedCharField(choices=ROLE_CHOICES, unique=True, max_length=30)
+
+    def __unicode__(self):  return u'%s' % (self.role)
+
+class ServicePrivilege(PlCoreBase):
+    user = models.ForeignKey('User', related_name='serviceprivileges')
+    service = models.ForeignKey('Service', related_name='serviceprivileges')
+    role = models.ForeignKey('ServiceRole',related_name='serviceprivileges')
+
+    class Meta:
+        unique_together =  ('user', 'service', 'role')
+
+    def __unicode__(self):  return u'%s %s %s' % (self.service, self.user, self.role)
+
+    def can_update(self, user):
+        if not self.service.enabled:
+            raise PermissionDenied, "Cannot modify permission(s) of a disabled service"
+        return self.service.can_update(user)
+
+    def save(self, *args, **kwds):
+        if not self.service.enabled:
+            raise PermissionDenied, "Cannot modify permission(s) of a disabled service"
+        super(ServicePrivilege, self).save(*args, **kwds)
+
+    def delete(self, *args, **kwds):
+        if not self.service.enabled:
+            raise PermissionDenied, "Cannot modify permission(s) of a disabled service"
+        super(ServicePrivilege, self).delete(*args, **kwds)
+
+    @classmethod
+    def select_by_user(cls, user):
+        if user.is_admin:
+            qs = cls.objects.all()
+        else:
+            qs = cls.objects.filter(user=user)
+        return qs
+
+class TenantRoot(PlCoreBase, AttributeMixin):
+    """ A tenantRoot is one of the things that can sit at the root of a chain
+        of tenancy. This object represents a node.
+    """
+
+    KIND= "generic"
+    kind = StrippedCharField(max_length=30, default=KIND)
+    name = StrippedCharField(max_length=255, help_text="name", blank=True, null=True)
+
+    service_specific_attribute = models.TextField(blank=True, null=True)
+    service_specific_id = StrippedCharField(max_length=30, blank=True, null=True)
+
+    def __init__(self, *args, **kwargs):
+        # for subclasses, set the default kind appropriately
+        self._meta.get_field("kind").default = self.KIND
+        super(TenantRoot, self).__init__(*args, **kwargs)
+
+    def __unicode__(self):
+        if not self.name:
+            return u"%s-tenant_root-#%s" % (str(self.kind), str(self.id))
+        else:
+            return self.name
+
+    def can_update(self, user):
+        return user.can_update_tenant_root(self, allow=['admin'])
+
+    def get_subscribed_tenants(self, tenant_class):
+        ids = self.subscribed_tenants.filter(kind=tenant_class.KIND)
+        return tenant_class.objects.filter(id__in = ids)
+
+    def get_newest_subscribed_tenant(self, kind):
+        st = list(self.get_subscribed_tenants(kind))
+        if not st:
+            return None
+        return sorted(st, key=attrgetter('id'))[0]
+
+    @classmethod
+    def get_tenant_objects(cls):
+        return cls.objects.filter(kind = cls.KIND)
+
+    @classmethod
+    def get_tenant_objects_by_user(cls, user):
+        return cls.select_by_user(user).filter(kind = cls.KIND)
+
+    @classmethod
+    def select_by_user(cls, user):
+        if user.is_admin:
+            return cls.objects.all()
+        else:
+            tr_ids = [trp.tenant_root.id for trp in TenantRootPrivilege.objects.filter(user=user)]
+            return cls.objects.filter(id__in=tr_ids)
+
+class Tenant(PlCoreBase, AttributeMixin):
+    """ A tenant is a relationship between two entities, a subscriber and a
+        provider. This object represents an edge.
+
+        The subscriber can be a User, a Service, or a Tenant.
+
+        The provider is always a Service.
+
+        TODO: rename "Tenant" to "Tenancy"
+    """
+
+    CONNECTIVITY_CHOICES = (('public', 'Public'), ('private', 'Private'), ('na', 'Not Applicable'))
+
+    # when subclassing a service, redefine KIND to describe the new service
+    KIND = "generic"
+
+    kind = StrippedCharField(max_length=30, default=KIND)
+    provider_service = models.ForeignKey(Service, related_name='provided_tenants')
+
+    # The next four things are the various type of objects that can be subscribers of this Tenancy
+    # relationship. One and only one can be used at a time.
+    subscriber_service = models.ForeignKey(Service, related_name='subscribed_tenants', blank=True, null=True)
+    subscriber_tenant = models.ForeignKey("Tenant", related_name='subscribed_tenants', blank=True, null=True)
+    subscriber_user = models.ForeignKey("User", related_name='subscribed_tenants', blank=True, null=True)
+    subscriber_root = models.ForeignKey("TenantRoot", related_name="subscribed_tenants", blank=True, null=True)
+
+    # Service_specific_attribute and service_specific_id are opaque to XOS
+    service_specific_id = StrippedCharField(max_length=30, blank=True, null=True)
+    service_specific_attribute = models.TextField(blank=True, null=True)
+
+    # Connect_method is only used by Coarse tenants
+    connect_method = models.CharField(null=False, blank=False, max_length=30, choices=CONNECTIVITY_CHOICES, default="na")
+
+    def __init__(self, *args, **kwargs):
+        # for subclasses, set the default kind appropriately
+        self._meta.get_field("kind").default = self.KIND
+        super(Tenant, self).__init__(*args, **kwargs)
+
+    def __unicode__(self):
+        return u"%s-tenant-%s" % (str(self.kind), str(self.id))
+
+    @classmethod
+    def get_tenant_objects(cls):
+        return cls.objects.filter(kind = cls.KIND)
+
+    @classmethod
+    def get_tenant_objects_by_user(cls, user):
+        return cls.select_by_user(user).filter(kind = cls.KIND)
+
+    @classmethod
+    def get_deleted_tenant_objects(cls):
+        return cls.deleted_objects.filter(kind = cls.KIND)
+
+    @property
+    def tenantattribute_dict(self):
+        attrs = {}
+        for attr in self.tenantattributes.all():
+            attrs[attr.name] = attr.value
+        return attrs
+
+    # helper function to be used in subclasses that want to ensure service_specific_id is unique
+    def validate_unique_service_specific_id(self):
+        if self.pk is None:
+            if self.service_specific_id is None:
+                raise XOSMissingField("subscriber_specific_id is None, and it's a required field", fields={"service_specific_id": "cannot be none"})
+
+            conflicts = self.get_tenant_objects().filter(service_specific_id=self.service_specific_id)
+            if conflicts:
+                raise XOSDuplicateKey("service_specific_id %s already exists" % self.service_specific_id, fields={"service_specific_id": "duplicate key"})
+
+    def save(self, *args, **kwargs):
+        subCount = sum( [1 for e in [self.subscriber_service, self.subscriber_tenant, self.subscriber_user, self.subscriber_root] if e is not None])
+        if (subCount > 1):
+            raise XOSConflictingField("Only one of subscriber_service, subscriber_tenant, subscriber_user, subscriber_root should be set")
+
+        super(Tenant, self).save(*args, **kwargs)
+
+    def get_subscribed_tenants(self, tenant_class):
+        ids = self.subscribed_tenants.filter(kind=tenant_class.KIND)
+        return tenant_class.objects.filter(id__in = ids)
+
+    def get_newest_subscribed_tenant(self, kind):
+        st = list(self.get_subscribed_tenants(kind))
+        if not st:
+            return None
+        return sorted(st, key=attrgetter('id'))[0]
+
+class Scheduler(object):
+    # XOS Scheduler Abstract Base Class
+    # Used to implement schedulers that pick which node to put instances on
+
+    def __init__(self, slice):
+        self.slice = slice
+
+    def pick(self):
+        # this method should return a tuple (node, parent)
+        #    node is the node to instantiate on
+        #    parent is for container_vm instances only, and is the VM that will
+        #      hold the container
+
+        raise Exception("Abstract Base")
+
+class LeastLoadedNodeScheduler(Scheduler):
+    # This scheduler always return the node with the fewest number of instances.
+
+    def __init__(self, slice):
+        super(LeastLoadedNodeScheduler, self).__init__(slice)
+
+    def pick(self):
+        from core.models import Node
+#        nodes = list(Node.objects.all())
+        if not self.slice.default_node:
+            nodes = list(Node.objects.all())
+            nodes = sorted(nodes, key=lambda node: node.instances.all().count())
+        else:
+            nodes = list(Node.objects.filter(name = self.slice.default_node))
+        # TODO: logic to filter nodes by which nodes are up, and which
+        #   nodes the slice can instantiate on.
+#        nodes = sorted(nodes, key=lambda node: node.instances.all().count())
+        return [nodes[0], None]
+
+class ContainerVmScheduler(Scheduler):
+    # This scheduler picks a VM in the slice with the fewest containers inside
+    # of it. If no VMs are suitable, then it creates a VM.
+
+    # this is a hack and should be replaced by something smarter...
+    LOOK_FOR_IMAGES=["ubuntu-vcpe4",        # ONOS demo machine -- preferred vcpe image
+                     "Ubuntu 14.04 LTS",    # portal
+                     "Ubuntu-14.04-LTS",    # ONOS demo machine
+                     "trusty-server-multi-nic", # CloudLab
+                    ]
+
+    MAX_VM_PER_CONTAINER = 10
+
+    def __init__(self, slice):
+        super(ContainerVmScheduler, self).__init__(slice)
+
+    @property
+    def image(self):
+        from core.models import Image
+
+        look_for_images = self.LOOK_FOR_IMAGES
+        for image_name in look_for_images:
+            images = Image.objects.filter(name = image_name)
+            if images:
+                return images[0]
+
+        raise XOSProgrammingError("No ContainerVM image (looked for %s)" % str(look_for_images))
+
+    def make_new_instance(self):
+        from core.models import Instance, Flavor
+
+        flavors = Flavor.objects.filter(name="m1.small")
+        if not flavors:
+            raise XOSConfigurationError("No m1.small flavor")
+
+        (node,parent) = LeastLoadedNodeScheduler(self.slice).pick()
+
+        instance = Instance(slice = self.slice,
+                        node = node,
+                        image = self.image,
+                        creator = self.slice.creator,
+                        deployment = node.site_deployment.deployment,
+                        flavor = flavors[0],
+                        isolation = "vm",
+                        parent = parent)
+        instance.save()
+        # We rely on a special naming convention to identify the VMs that will
+        # hole containers.
+        instance.name = "%s-outer-%s" % (instance.slice.name, instance.id)
+        instance.save()
+        return instance
+
+    def pick(self):
+        from core.models import Instance, Flavor
+
+        for vm in self.slice.instances.filter(isolation="vm"):
+            avail_vms = []
+            if (vm.name.startswith("%s-outer-" % self.slice.name)):
+                container_count = Instance.objects.filter(parent=vm).count()
+                if (container_count < self.MAX_VM_PER_CONTAINER):
+                    avail_vms.append( (vm, container_count) )
+            # sort by least containers-per-vm
+            avail_vms = sorted(avail_vms, key = lambda x: x[1])
+            print "XXX", avail_vms
+            if avail_vms:
+                instance = avail_vms[0][0]
+                return (instance.node, instance)
+
+        instance = self.make_new_instance()
+        return (instance.node, instance)
+
+class TenantWithContainer(Tenant):
+    """ A tenant that manages a container """
+
+    # this is a hack and should be replaced by something smarter...
+    LOOK_FOR_IMAGES=["ubuntu-vcpe4",        # ONOS demo machine -- preferred vcpe image
+                     "Ubuntu 14.04 LTS",    # portal
+                     "Ubuntu-14.04-LTS",    # ONOS demo machine
+                     "trusty-server-multi-nic", # CloudLab
+                    ]
+
+    LOOK_FOR_CONTAINER_IMAGES=["docker-vcpe"]
+
+    class Meta:
+        proxy = True
+
+    def __init__(self, *args, **kwargs):
+        super(TenantWithContainer, self).__init__(*args, **kwargs)
+        self.cached_instance=None
+        self.orig_instance_id = self.get_initial_attribute("instance_id")
+
+    @property
+    def instance(self):
+        from core.models import Instance
+        if getattr(self, "cached_instance", None):
+            return self.cached_instance
+        instance_id=self.get_attribute("instance_id")
+        if not instance_id:
+            return None
+        instances=Instance.objects.filter(id=instance_id)
+        if not instances:
+            return None
+        instance=instances[0]
+        instance.caller = self.creator
+        self.cached_instance = instance
+        return instance
+
+    @instance.setter
+    def instance(self, value):
+        if value:
+            value = value.id
+        if (value != self.get_attribute("instance_id", None)):
+            self.cached_instance=None
+        self.set_attribute("instance_id", value)
+
+    @property
+    def external_hostname(self):
+        return self.get_attribute("external_hostname", "")
+
+    @external_hostname.setter
+    def external_hostname(self, value):
+        self.set_attribute("external_hostname", value)
+
+    @property
+    def external_container(self):
+        return self.get_attribute("external_container", "")
+
+    @external_container.setter
+    def external_container(self, value):
+        self.set_attribute("external_container", value)
+
+    @property
+    def creator(self):
+        from core.models import User
+        if getattr(self, "cached_creator", None):
+            return self.cached_creator
+        creator_id=self.get_attribute("creator_id")
+        if not creator_id:
+            return None
+        users=User.objects.filter(id=creator_id)
+        if not users:
+            return None
+        user=users[0]
+        self.cached_creator = users[0]
+        return user
+
+    @creator.setter
+    def creator(self, value):
+        if value:
+            value = value.id
+        if (value != self.get_attribute("creator_id", None)):
+            self.cached_creator=None
+        self.set_attribute("creator_id", value)
+
+    @property
+    def image(self):
+        from core.models import Image
+        # Implement the logic here to pick the image that should be used when
+        # instantiating the VM that will hold the container.
+
+        slice = self.provider_service.slices.all()
+        if not slice:
+            raise XOSProgrammingError("provider service has no slice")
+        slice = slice[0]
+
+        if slice.default_isolation in ["container", "container_vm"]:
+            look_for_images = self.LOOK_FOR_CONTAINER_IMAGES
+        else:
+            look_for_images = self.LOOK_FOR_IMAGES
+
+        for image_name in look_for_images:
+            images = Image.objects.filter(name = image_name)
+            if images:
+                return images[0]
+
+        raise XOSProgrammingError("No VPCE image (looked for %s)" % str(look_for_images))
+
+    def save_instance(self, instance):
+        # Override this function to do custom pre-save or post-save processing,
+        # such as creating ports for containers.
+        instance.save()
+
+    def pick_least_loaded_instance_in_slice(self, slices):
+        for slice in slices:
+            if slice.instances.all().count() > 0:
+                for instance in slice.instances.all():
+                     #Pick the first instance that has lesser than 5 tenants 
+                     if self.count_of_tenants_of_an_instance(instance) < 5:
+                         return instance
+        return None
+
+    #TODO: Ideally the tenant count for an instance should be maintained using a 
+    #many-to-one relationship attribute, however this model being proxy, it does 
+    #not permit any new attributes to be defined. Find if any better solutions 
+    def count_of_tenants_of_an_instance(self, instance):
+        tenant_count = 0
+        for tenant in self.get_tenant_objects().all():
+            if tenant.get_attribute("instance_id", None) == instance.id:
+                tenant_count += 1
+        return tenant_count
+
+    def manage_container(self):
+        from core.models import Instance, Flavor
+
+        if self.deleted:
+            return
+
+        if (self.instance is not None): #  and (self.instance.image != self.image):
+            self.instance.delete()
+            self.instance = None
+
+        if self.instance is None:
+            if not self.provider_service.slices.count():
+                raise XOSConfigurationError("The service has no slices")
+
+            new_instance_created = False
+            instance = None
+            if self.get_attribute("use_same_instance_for_multiple_tenants", default=False):
+                #Find if any existing instances can be used for this tenant
+                slices = self.provider_service.slices.all()
+                instance = self.pick_least_loaded_instance_in_slice(slices)
+
+            if not instance:
+                flavors = Flavor.objects.filter(name="m1.small")
+                if not flavors:
+                    raise XOSConfigurationError("No m1.small flavor")
+
+                slice = self.provider_service.slices.all()[0]
+
+                if slice.default_isolation == "container_vm":
+                    (node, parent) = ContainerVmScheduler(slice).pick()
+                else:
+                    (node, parent) = LeastLoadedNodeScheduler(slice).pick()
+
+                instance = Instance(slice = slice,
+                                node = node,
+#                                image = slice.default_image,
+                                image = self.image,
+                                creator = self.creator,
+                                deployment = node.site_deployment.deployment,
+#                                flavor = flavors[0],
+                                flavor = slice.default_flavor,
+                                isolation = slice.default_isolation,
+                                parent = parent)
+                self.save_instance(instance)
+                new_instance_created = True
+
+            try:
+                self.instance = instance
+                super(TenantWithContainer, self).save()
+            except:
+                if new_instance_created:
+                    instance.delete()
+                raise
+
+    def cleanup_container(self):
+        if self.instance:
+            if self.get_attribute("use_same_instance_for_multiple_tenants", default=False):
+                #Delete the instance only if this is last tenant in that instance
+                tenant_count = self.count_of_tenants_of_an_instance(self.instance)
+                if tenant_count == 0:
+                    self.instance.delete()
+            else:
+                self.instance.delete()
+            self.instance = None
+
+    def save(self, *args, **kwargs):
+        if (not self.creator) and (hasattr(self, "caller")) and (self.caller):
+            self.creator = self.caller
+        super(TenantWithContainer, self).save(*args, **kwargs)
+
+class CoarseTenant(Tenant):
+    """ TODO: rename "CoarseTenant" --> "StaticTenant" """
+    class Meta:
+        proxy = True
+
+    KIND = COARSE_KIND
+
+    def save(self, *args, **kwargs):
+        if (not self.subscriber_service):
+            raise XOSValidationError("subscriber_service cannot be null")
+        if (self.subscriber_tenant or self.subscriber_user):
+            raise XOSValidationError("subscriber_tenant and subscriber_user must be null")
+
+        super(CoarseTenant,self).save()
+
+class Subscriber(TenantRoot):
+    """ Intermediate class for TenantRoots that are to be Subscribers """
+
+    class Meta:
+        proxy = True
+
+    KIND = "Subscriber"
+
+class Provider(TenantRoot):
+    """ Intermediate class for TenantRoots that are to be Providers """
+
+    class Meta:
+        proxy = True
+
+    KIND = "Provider"
+
+class TenantAttribute(PlCoreBase):
+    name = models.CharField(help_text="Attribute Name", max_length=128)
+    value = models.TextField(help_text="Attribute Value")
+    tenant = models.ForeignKey(Tenant, related_name='tenantattributes', help_text="The Tenant this attribute is associated with")
+
+class TenantRootRole(PlCoreBase):
+    ROLE_CHOICES = (('admin','Admin'), ('access','Access'))
+
+    role = StrippedCharField(choices=ROLE_CHOICES, unique=True, max_length=30)
+
+    def __unicode__(self):  return u'%s' % (self.role)
+
+class TenantRootPrivilege(PlCoreBase):
+    user = models.ForeignKey('User', related_name="tenant_root_privileges")
+    tenant_root = models.ForeignKey('TenantRoot', related_name="tenant_root_privileges")
+    role = models.ForeignKey('TenantRootRole', related_name="tenant_root_privileges")
+
+    class Meta:
+        unique_together = ('user', 'tenant_root', 'role')
+
+    def __unicode__(self):  return u'%s %s %s' % (self.tenant_root, self.user, self.role)
+
+    def save(self, *args, **kwds):
+        if not self.user.is_active:
+            raise PermissionDenied, "Cannot modify role(s) of a disabled user"
+        super(TenantRootPrivilege, self).save(*args, **kwds)
+
+    def can_update(self, user):
+        return user.can_update_tenant_root_privilege(self)
+
+    @classmethod
+    def select_by_user(cls, user):
+        if user.is_admin:
+            return cls.objects.all()
+        else:
+            # User can see his own privilege
+            trp_ids = [trp.id for trp in cls.objects.filter(user=user)]
+
+            # A slice admin can see the SlicePrivileges for his Slice
+            for priv in cls.objects.filter(user=user, role__role="admin"):
+                trp_ids.extend( [trp.id for trp in cls.objects.filter(tenant_root=priv.tenant_root)] )
+
+            return cls.objects.filter(id__in=trp_ids)
+
+