diff --git a/plstackapi/core/api/deployment_networks.py b/plstackapi/core/api/deployment_networks.py
index 812ca15..80b4ff3 100644
--- a/plstackapi/core/api/deployment_networks.py
+++ b/plstackapi/core/api/deployment_networks.py
@@ -2,7 +2,17 @@
 from plstackapi.openstack.driver import OpenStackDriver
 from plstackapi.core.api.auth import auth_check
 from plstackapi.core.models import DeploymentNetwork
- 
+
+def _get_deployment_networks(filter):
+    if isinstance(filter, int):
+        deployment_networks = DeploymentNetwork.objects.filter(id=filter)
+    elif isinstance(filter, StringTypes):
+        deployment_networks = DeploymentNetwork.objects.filter(name=filter)
+    elif isinstance(filer, dict):
+        deployment_networks = DeploymentNetwork.objects.filter(**filter)
+    else:
+        deployment_networks = []
+    return deployment_networks 
 
 def add_deployment_network(auth, name):
     auth_check(auth)    
@@ -12,14 +22,14 @@
 
 def delete_deployment_network(auth, filter={}):
     auth_check(auth)   
-    deployments = DeploymentNetwork.objects.filter(**filter)
+    deployments = _get_deployment_networks(filter)
     for deployment in deployments:
         deployment.delete()
     return 1
 
 def get_deployment_networks(auth, filter={}):
     auth_check(auth)   
-    deployments = DeploymentNetwork.objects.filter(**filter)
+    deployments = _get_deployment_networks(filter)
     return deployments             
         
 
diff --git a/plstackapi/core/api/flavors.py b/plstackapi/core/api/flavors.py
index a2d0b23..ee55f73 100644
--- a/plstackapi/core/api/flavors.py
+++ b/plstackapi/core/api/flavors.py
@@ -3,6 +3,16 @@
 from plstackapi.core.api.auth import auth_check
 from plstackapi.core.models import Flavor
  
+def _get_flavors(filter):
+    if isinstance(filter, int):
+        flavors = Flavor.objects.filter(id=filter)
+    elif isinstance(filter, StringTypes):
+        flavors = Flavor.objects.filter(name=filter)
+    elif isinstance(filer, dict):
+        flavors = Flavor.objects.filter(**filter)
+    else:
+        flavors = []
+    return flavors
 
 def add_flavor(auth, fields={}):
     """not implemented"""
@@ -14,7 +24,7 @@
 
 def get_flavors(auth, filter={}):
     auth_check(auth)   
-    flavors = Flavor.objects.filter(**filter)
+    flavors = _get_flavors(filter)
     return flavors             
         
 
diff --git a/plstackapi/core/api/images.py b/plstackapi/core/api/images.py
index b773b0b..0b14043 100644
--- a/plstackapi/core/api/images.py
+++ b/plstackapi/core/api/images.py
@@ -3,6 +3,16 @@
 from plstackapi.core.api.auth import auth_check
 from plstackapi.core.models import Image
  
+def _get_images(filter):
+    if isinstance(filter, int):
+        images = image.objects.filter(id=filter)
+    elif isinstance(filter, StringTypes):
+        images = image.objects.filter(name=filter)
+    elif isinstance(filer, dict):
+        images = image.objects.filter(**filter)
+    else:
+        images = []
+    return images
 
 def add_image(auth, fields={}):
     """not implemented"""
@@ -14,7 +24,7 @@
 
 def get_images(auth, filter={}):
     auth_check(auth)   
-    images = Image.objects.filter(**filter)
+    images = _get_images(filter)
     return images             
         
 
diff --git a/plstackapi/core/api/keys.py b/plstackapi/core/api/keys.py
index b255e98..2c90140 100644
--- a/plstackapi/core/api/keys.py
+++ b/plstackapi/core/api/keys.py
@@ -2,24 +2,24 @@
 from plstackapi.openstack.driver import OpenStackDriver
 from plstackapi.core.api.auth import auth_check
 from plstackapi.core.models import Key, User
- 
-def lookup_user(fields):
-    user = None
-    if 'user' in fields:
-        if isinstance(fields['user'], int):
-            users = User.objects.filter(id=fields['user'])
-        else:
-            users = User.objects.filter(email=fields['user'])
-        if users:
-            user = users[0]
-    if not user:
-        raise Exception, "No such user: %s" % fields['user']
-    return user 
+from plstackapi.core.api.users import _get_users
+
+
+def _get_keys(filter):
+    if isinstance(filter, int):
+        keys = Key.objects.filter(id=filter)
+    elif isinstance(filter, StringTypes):
+        keys = Key.objects.filter(name=filter)
+    elif isinstance(filer, dict):
+        keys = Key.objects.filter(**filter)
+    else:
+        keys = []
+    return keys 
 
 def add_key(auth, fields):
     driver = OpenStackDriver(client = auth_check(auth))
-    user = lookup_user(fields) 
-    if user: fields['user'] = user     
+    users = _get_users(fields.get('user')) 
+    if users: fields['user'] = users[0]    
     key = Key(**fields)
     nova_fields = {'name': key.name,
                    'key': key.key} 
@@ -32,7 +32,7 @@
 
 def delete_key(auth, filter={}):
     driver = OpenStackDriver(client = auth_check(auth))   
-    keys = Key.objects.filter(**filter)
+    keys = _get_keys(filter)
     for key in keys:
         driver.delete_keypair(name=key.name) 
         key.delete()
@@ -40,7 +40,7 @@
 
 def get_keys(auth, filter={}):
     client = auth_check(auth)
-    keys = Key.objects.filter(**filter)
+    keys = _get_keys(filter)
     return keys             
         
 
diff --git a/plstackapi/core/api/nodes.py b/plstackapi/core/api/nodes.py
new file mode 100644
index 0000000..47934ba
--- /dev/null
+++ b/plstackapi/core/api/nodes.py
@@ -0,0 +1,34 @@
+from plstackapi.openstack.client import OpenStackClient
+from plstackapi.openstack.driver import OpenStackDriver
+from plstackapi.core.api.auth import auth_check
+from plstackapi.core.models import Node
+ 
+def _get_nodes(filter):
+    if isinstance(filter, int):
+        nodes = Node.objects.filter(id=filter)
+    elif isinstance(filter, StringTypes):
+        nodes = Node.objects.filter(name=filter)
+    elif isinstance(filer, dict):
+        nodes = Node.objects.filter(**filter)
+    else:
+        nodes = []
+    return nodes
+
+def add_node(auth, fields={}):
+    """not implemented"""
+    return 
+
+def delete_node(auth, filter={}):
+    """not implemented"""
+    return 1
+
+def update_node(auth, id, fields={}):
+    return 
+
+def get_nodes(auth, filter={}):
+    auth_check(auth)   
+    nodes = _get_nodes(filter)
+    return nodes             
+        
+
+    
diff --git a/plstackapi/core/api/roles.py b/plstackapi/core/api/roles.py
index 844fb4f..6c61e25 100644
--- a/plstackapi/core/api/roles.py
+++ b/plstackapi/core/api/roles.py
@@ -1,9 +1,21 @@
+from types import StringTypes
 from plstackapi.openstack.client import OpenStackClient
 from plstackapi.openstack.driver import OpenStackDriver
 from plstackapi.core.api.auth import auth_check
 from plstackapi.core.models import Role
  
 
+def _get_roles(filter):
+    if isinstance(filter, int):
+        roles = Role.objects.filter(id=filter)
+    elif isinstance(filter, StringTypes):
+        roles = Role.objects.filter(role_type=filter)
+    elif isinstance(filter, dict):
+        roles = Role.objects.filter(**filter)
+    else:
+        roles = []
+    return roles
+
 def add_role(auth, name):
     driver = OpenStackDriver(client = auth_check(auth))    
     keystone_role = driver.create_role(name=name)
@@ -13,7 +25,7 @@
 
 def delete_role(auth, filter={}):
     driver = OpenStackDriver(client = auth_check(auth))   
-    roles = Role.objects.filter(**filter)
+    roles = _get_roles(filter) 
     for role in roles:
         driver.delete_role({'id': role.role_id}) 
         role.delete()
@@ -21,8 +33,5 @@
 
 def get_roles(auth, filter={}):
     client = auth_check(auth)
-    roles = Role.objects.filter(**filter)
-    return roles             
+    return _get_roles(filter)             
         
-
-    
diff --git a/plstackapi/core/api/site_privileges.py b/plstackapi/core/api/site_privileges.py
new file mode 100644
index 0000000..4c4158e
--- /dev/null
+++ b/plstackapi/core/api/site_privileges.py
@@ -0,0 +1,69 @@
+import re
+from plstackapi.openstack.client import OpenStackClient
+from plstackapi.openstack.driver import OpenStackDriver
+from plstackapi.core.api.auth import auth_check
+from plstackapi.core.models import SitePrivilege, Site, Role, User
+from plstackapi.core.api.users import _get_users
+from plstackapi.core.api.sites import _get_sites
+from plstackapi.core.api.roles import _get_roles
+
+
+def _get_site_privileges(filter):
+    if isinstance(filter, int):
+        site_privileges = SitePrivilege.objects.filter(id=filter)
+    elif isinstance(filter, StringTypes):
+        site_privileges = SitePrivilege.objects.filter(name=filter)
+    elif isinstance(filer, dict):
+        site_privileges = SitePrivilege.objects.filter(**filter)
+    else:
+        site_privileges = []
+    return site_privileges
+ 
+def add_site_privilege(auth, fields):
+    driver = OpenStackDriver(client = auth_check(auth))
+    users = _get_user(fields.get('user')) 
+    sites = _get_slice(fields.get('site')) 
+    roles = _get_role(fields.get('role'))
+    
+    if users: fields['user'] = users[0]     
+    if slices: fields['site'] = sites[0] 
+    if roles: fields['role'] = roles[0]
+ 
+    site_privilege = SitePrivilege(**fields)
+
+    # update nova role
+    driver.add_user_role(site_privilege.user.user_id, 
+                         site_privilege.site.tenant_id, 
+                         site_privilege.role.name)
+    
+    site_privilege.save()
+    return site_privilege
+
+def update_site_privilege(auth, id, **fields):
+    return  
+
+def delete_site_privilege(auth, filter={}):
+    driver = OpenStackDriver(client = auth_check(auth))   
+    site_privileges = _get_site_privileges(filter)
+    for site_privilege in site_privileges:
+        driver.delete_user_role(user_id=site_privilege.user.id,
+                                tenant_id = site_privilege.site.tenant_id,
+                                role_name = site_privilege.role.name) 
+        site_privilege.delete()
+    return 1
+
+def get_site_privileges(auth, filter={}):
+    client = auth_check(auth)
+    users = _get_users(filter.get('user'))
+    sites = _get_slices(filter.get('site'))
+    roles = _get_roles(filter.get('role'))
+
+    if users: filter['user'] = users[0]
+    if sites: filter['site'] = sites[0]
+    if roles: filter['role'] = roles[0]
+    
+    site_privileges = _get_site_privileges(filter)
+    return site_privileges             
+        
+
+    
diff --git a/plstackapi/core/api/sites.py b/plstackapi/core/api/sites.py
index 0d07605..540f815 100644
--- a/plstackapi/core/api/sites.py
+++ b/plstackapi/core/api/sites.py
@@ -2,7 +2,18 @@
 from plstackapi.openstack.driver import OpenStackDriver
 from plstackapi.core.api.auth import auth_check
 from plstackapi.core.models import Site
- 
+
+
+def _get_sites(filter):
+    if isinstance(filter, int):
+        sites = Site.objects.filter(id=filter)
+    elif isinstance(filter, StringTypes):
+        sites = Site.objects.filter(name=filter)
+    elif isinstance(filer, dict):
+        sites = Site.objects.filter(**filter)
+    else:
+        sites = []
+    return sites 
 
 def add_site(auth, fields):
     driver = OpenStackDriver(client = auth_check(auth))
@@ -17,7 +28,7 @@
 
 def update_site(auth, id, **fields):
     driver = OpenStackDriver(client = auth_check(auth))
-    sites = Site.objects.filter(id=id)
+    sites = _get_sites(id)
     if not sites:
         return
 
@@ -33,7 +44,7 @@
 
 def delete_site(auth, filter={}):
     driver = OpenStackDriver(client = auth_check(auth))   
-    sites = Site.objects.filter(**filter)
+    sites = _get_sites(id)
     for site in sites:
         driver.delete_tenant(id=site.tenant_id) 
         site.delete()
@@ -41,7 +52,7 @@
 
 def get_sites(auth, filter={}):
     client = auth_check(auth)
-    sites = Site.objects.filter(**filter)
+    sites = _get_sites(id)
     return sites             
         
 
diff --git a/plstackapi/core/api/slice_memberships.py b/plstackapi/core/api/slice_memberships.py
new file mode 100644
index 0000000..9193632
--- /dev/null
+++ b/plstackapi/core/api/slice_memberships.py
@@ -0,0 +1,69 @@
+import re
+from plstackapi.openstack.client import OpenStackClient
+from plstackapi.openstack.driver import OpenStackDriver
+from plstackapi.core.api.auth import auth_check
+from plstackapi.core.models import SliceMembership, Slice, Role, User
+from plstackapi.core.api.users import _get_users
+from plstackapi.core.api.slices import _get_slices
+from plstackapi.core.api.roles import _get_roles
+
+def _get_slice_memberships(filter):
+    if isinstance(filter, int):
+        slice_memberships = SitePrivilege.objects.filter(id=filter)
+    elif isinstance(filter, StringTypes):
+        slice_memberships = SitePrivilege.objects.filter(name=filter)
+    elif isinstance(filer, dict):
+        slice_memberships = SitePrivilege.objects.filter(**filter)
+    else:
+        slice_memberships = []
+    return slice_memberships
+
+ 
+def add_slice_membership(auth, fields):
+    driver = OpenStackDriver(client = auth_check(auth))
+    users = _get_users(fields.get('user')) 
+    slices = _get_slices(fields.get('slice')) 
+    roles = _get_roles(fields.get('role'))
+    
+    if users: fields['user'] = users[0]     
+    if slices: fields['slice'] = slices[0] 
+    if roles: fields['role'] = roles[0]
+ 
+    slice_membership = SliceMembership(**fields)
+
+    # update nova role
+    driver.add_user_role(slice_membership.user.user_id, 
+                         slice_membership.slice.tenant_id, 
+                         slice_membership.role.name)
+    
+    slice_membership.save()
+    return slice_membership
+
+def update_slice_membership(auth, id, **fields):
+    return  
+
+def delete_slice_membership(auth, filter={}):
+    driver = OpenStackDriver(client = auth_check(auth))   
+    slice_memberships = _get_slice_memberships(filter)
+    for slice_membership in slice_memberships:
+        driver.delete_user_role(user_id=slice_membership.user.id,
+                                tenant_id = slice_membership.slice.tenant_id,
+                                role_name = slice_membership.role.name) 
+        slice_membership.delete()
+    return 1
+
+def get_slice_memberships(auth, filter={}):
+    client = auth_check(auth)
+    users = _get_users(fields.get('user'))
+    slices = _get_slices(fields.get('slice'))
+    roles = _get_roles(fields.get('role'))
+
+    if users: fields['user'] = users[0]
+    if slices: fields['slice'] = slices[0]
+    if roles: fields['role'] = roles[0]
+
+    slice_memberships = _get_slice_memberships(filter)
+    return slice_memberships             
+        
+
+    
diff --git a/plstackapi/core/api/slices.py b/plstackapi/core/api/slices.py
index 3f50050..731fa75 100644
--- a/plstackapi/core/api/slices.py
+++ b/plstackapi/core/api/slices.py
@@ -2,43 +2,26 @@
 from plstackapi.openstack.client import OpenStackClient
 from plstackapi.openstack.driver import OpenStackDriver
 from plstackapi.core.api.auth import auth_check
-from plstackapi.core.models import Slice, Site
+from plstackapi.core.models import Slice
+from plstackapi.core.api.sites import _get_sites
+
+
+def _get_slices(filter):
+    if isinstance(filter, int):
+        slices = Slice.objects.filter(id=filter)
+    elif isinstance(filter, StringTypes):
+        slices = Slice.objects.filter(name=filter)
+    elif isinstance(filer, dict):
+        slices = Slice.objects.filter(**filter)
+    else:
+        slices = []
+    return slices
+    
  
-def validate_name(name):
-    # N.B.: Responsibility of the caller to ensure that login_base
-        # portion of the slice name corresponds to a valid site, if
-        # desired.
-
-        # 1. Lowercase.
-        # 2. Begins with login_base (letters or numbers).
-        # 3. Then single underscore after login_base.
-        # 4. Then letters, numbers, or underscores.
-        good_name = r'^[a-z0-9]+_[a-zA-Z0-9_]+$'
-        if not name or \
-           not re.match(good_name, name):
-            raise Exception, "Invalid slice name: %s" % name
-
-def lookup_site(fields):
-    site = None
-    if 'name' in fields:
-        validate_name(fields['name'])
-        login_base = fields['name'][:fields['name'].find('_')]        
-        sites = Site.objects.filter(login_base=login_base)
-        if sites:
-            site = sites[0]
-    elif 'site' in fields:
-        if isinstance(fields['site'], int):
-            sites = Site.objects.filter(id=fields['site'])
-        else:
-            sites = Site.objects.filter(login_base=fields['site'])
-        if sites:
-            site = sites[0]     
-    return site 
-
 def add_slice(auth, fields):
     driver = OpenStackDriver(client = auth_check(auth))
-    site = lookup_site(fields) 
-    if site: fields['site'] = site     
+    sites = _get_sites(fields.get('site')) 
+    if sites: fields['site'] = sites[0]     
     slice = Slice(**fields)
     # create tenant
     nova_fields = {'tenant_name': slice.name,
@@ -60,7 +43,7 @@
 
 def update_slice(auth, id, **fields):
     driver = OpenStackDriver(client = auth_check(auth))
-    slices = Slice.objects.filter(id=id)
+    slices = _get_slices(id)
     if not slices:
         return
 
@@ -76,15 +59,15 @@
     driver.update_tenant(slice.tenant_id, **nova_fields)
 
     # update db record 
-    site = lookup_site(fields)
-    if site: fields['site'] = site
+    sites = _get_sites(fields.get('site'))
+    if sites: fields['site'] = sites[0]
     slice.update(**fields)
 
     return slice 
 
 def delete_slice(auth, filter={}):
     driver = OpenStackDriver(client = auth_check(auth))   
-    slices = Slice.objects.filter(**filter)
+    slices = _get_slices(id)
     for slice in slices:
         driver.delete_slice(id=slice.tenant_id) 
         slice.delete()
@@ -93,9 +76,9 @@
 def get_slices(auth, filter={}):
     client = auth_check(auth)
     if 'site' in filter:
-         site = lookup_site(filter)
-    if site: filter['site'] = site
-    slices = Slice.objects.filter(**filter)
+        sites = _get_sites(filter.get('site'))
+        if sites: filter['site'] = sites[0]
+    slices = _get_slices(filter)
     return slices             
         
 
diff --git a/plstackapi/core/api/slivers.py b/plstackapi/core/api/slivers.py
new file mode 100644
index 0000000..0bdaa5d
--- /dev/null
+++ b/plstackapi/core/api/slivers.py
@@ -0,0 +1,74 @@
+import re
+from plstackapi.openstack.client import OpenStackClient
+from plstackapi.openstack.driver import OpenStackDriver
+from plstackapi.core.api.auth import auth_check
+from plstackapi.core.models import Sliver, Slice
+from plstackapi.core.api.flavors import _get_flavors
+from plstackapi.core.api.images import _get_images
+from plstackapi.core.api.keys import _get_keys
+from plstackapi.core.api.slices import _get_slices
+from plstackapi.core.api.deployment_networks import _get_deployment_networks
+from plstackapi.core.api.nodes import _get_nodes
+ 
+
+def _get_slivers(filter):
+    if isinstance(filter, int):
+        slivers = Sliver.objects.filter(id=filter)
+    elif isinstance(filter, StringTypes):
+        slivers = Sliver.objects.filter(name=filter)
+    elif isinstance(filer, dict):
+        slivers = Sliver.objects.filter(**filter)
+    else:
+        slivers = []
+    return slivers
+ 
+def add_sliver(auth, fields):
+    driver = OpenStackDriver(client = auth_check(auth))
+    
+    flavors = _get_flavor(fields.get('flavor'))
+    if flavors: fields['flavor'] = flavors[0]     
+    images = _get_images(fields.get('image'))
+    if images: fields['image'] = images[0]     
+    keys = _get_keys(fields.get('get'))
+    if keys: fields['key'] = keys[0]     
+    slices = _get_slices(fields.get('slice'))
+    if slices: fields['slice'] = slices[0]     
+    deployment_networks = _get_deployment_networks(field.get('deployment_network'))
+    if deployment_networks: fields['deployment_network'] = deployment_networks[0]     
+    nodes = _get_nodes(fields.get('node'))
+    if nodes: fields['node'] = nodess[0]     
+    
+    sliver = Sliver(**fields)
+    # create quantum sliver
+    sliver = driver.spawn_instance(name=sliver.name,
+                                   key_name = sliver.key.name,
+                                   flavor=sliver.flavor.name,
+                                   image = sliver.image.name,
+                                   hostname = sliver.node.hostname )
+
+    sliver.instance_id=sliver.id
+
+    sliver.save()
+    return sliver
+
+def update_sliver(auth, sliver, **fields):
+    return  
+
+def delete_sliver(auth, filter={}):
+    driver = OpenStackDriver(client = auth_check(auth))   
+    slivers = _get_slivers(filter)
+    for sliver in slivers:
+        driver.destroy_instance(sliver.sliver_id) 
+        sliver.delete()
+    return 1
+
+def get_slivers(auth, filter={}):
+    client = auth_check(auth)
+    if 'slice' in filter:
+        slices = _get_slices(filter.get('slice'))
+        if slices: filter['slice'] = slices[0]
+    slivers = _get_slivers(filter)
+    return slivers             
+        
+
+    
diff --git a/plstackapi/core/api/subnets.py b/plstackapi/core/api/subnets.py
new file mode 100644
index 0000000..ad53da0
--- /dev/null
+++ b/plstackapi/core/api/subnets.py
@@ -0,0 +1,61 @@
+import re
+from plstackapi.openstack.client import OpenStackClient
+from plstackapi.openstack.driver import OpenStackDriver
+from plstackapi.core.api.auth import auth_check
+from plstackapi.core.models import Subnet
+from plstackapi.core.api.slices import _get_slices
+
+def _get_subnets(filter):
+    if isinstance(filter, int):
+        subnets = Subnet.objects.filter(id=filter)
+    elif isinstance(filter, StringTypes):
+        subnets = Subnet.objects.filter(name=filter)
+    elif isinstance(filer, dict):
+        subnets = Subnet.objects.filter(**filter)
+    else:
+        subnets = []
+    return subnets
+
+def add_subnet(auth, fields):
+    driver = OpenStackDriver(client = auth_check(auth))
+    slices = _get_slice(fields.get('slice')) 
+    if slices: fields['slice'] = slices[0]     
+    subnet = Subnet(**fields)
+    # create quantum subnet
+    subnet = driver.create_subnet(network_name=subnet.name,
+                                  cidr_ip = subnet.cidr,
+                                  ip_version=subnet.ip_version,
+                                  start = subnet.start,
+                                  end = subnet.end,
+                                  dns_nameservers = ['8.8.8.8', '8.8.4.4'])
+
+    subnet.subnet_id=subnet.id
+
+    # add subnet as interface to slice's router
+    driver.add_router_interface(subnet.slice.router_id, subnet.subnet_id)     
+    
+    subnet.save()
+    return subnet
+
+def update_subnet(auth, subnet, **fields):
+    return  
+
+def delete_subnet(auth, filter={}):
+    driver = OpenStackDriver(client = auth_check(auth))   
+    subnets = Subnet.objects.filter(**filter)
+    for subnet in subnets:
+        driver.delete_router_interface(subnet.slice.router_id, subnet.subnet_id)
+        driver.delete_subnet(subnet.subnet_id) 
+        subnet.delete()
+    return 1
+
+def get_subnets(auth, filter={}):
+    client = auth_check(auth)
+    if 'slice' in filter:
+        slice = _get_slice(filter.get('slice'))
+        if slice: filter['slice'] = slice
+    subnets = Subnet.objects.filter(**filter)
+    return subnets             
+        
+
+    
diff --git a/plstackapi/core/api/users.py b/plstackapi/core/api/users.py
index 18a68c7..d543782 100644
--- a/plstackapi/core/api/users.py
+++ b/plstackapi/core/api/users.py
@@ -2,31 +2,30 @@
 from plstackapi.openstack.driver import OpenStackDriver
 from plstackapi.core.api.auth import auth_check
 from plstackapi.core.models import User, Site
- 
-def lookup_site(fields):
-    site = None
-    if 'site' in fields:
-        if isinstance(fields['site'], int):
-            sites = Site.objects.filter(id=fields['site'])
-        else:
-            sites = Site.objects.filter(login_base=fields['site'])
-        if sites:
-            site = sites[0]
-    if not site:
-        raise Exception, "No such site: %s" % fields['site']
-    return site 
+from plstackapi.core.api.sites import _get_sites
+
+def _get_users(filter):
+    if isinstance(filter, int):
+        users = User.objects.filter(id=filter)
+    elif isinstance(filter, StringTypes):
+        users = User.objects.filter(role_type=filter)
+    elif isinstance(filer, dict):
+        users = User.objects.filter(**filter)
+    else:
+        users = []
+    return users 
 
 def add_user(auth, fields):
     driver = OpenStackDriver(client = auth_check(auth))
-    site = lookup_site(fields) 
-    if site: fields['site'] = site     
+    sites = _get_sites(fields.get('site')) 
+    if sites: fields['site'] = sites[0]     
     user = User(**fields)
     nova_fields = {'name': user.email[:user.email.find('@')],
                    'email': user.email, 
                    'password': fields.get('password'),
                    'enabled': user.enabled}    
     nova_user = driver.create_user(**nova_fields)
-    #driver.add_user_role(user.id, user.site.tenant_id, 'user')
+    #driver.add_user_user(user.id, user.site.tenant_id, 'user')
     user.user_id=nova_user.id
     user.save()
     return user
@@ -47,14 +46,14 @@
     if 'enabled' in fields:
         nova_fields['enabled'] = fields['enabled']
     driver.update_user(user.user_id, **nova_fields)
-    site = lookup_site(fields)
-    if site: fields['site'] = site
+    sites = _get_sites(fields.get('site'))
+    if sites: fields['site'] = sites[0]
     user.update(**fields)
     return user 
 
 def delete_user(auth, filter={}):
     driver = OpenStackDriver(client = auth_check(auth))   
-    users = User.objects.filter(**filter)
+    users = _get_users(filter)
     for user in users:
         driver.delete_user(id=user.user_id) 
         user.delete()
@@ -62,7 +61,7 @@
 
 def get_users(auth, filter={}):
     client = auth_check(auth)
-    users = User.objects.filter(**filter)
+    users = _get_users(filter)
     return users