introduce Controller model
diff --git a/planetstack/core/models/controlleruser.py b/planetstack/core/models/controlleruser.py
new file mode 100644
index 0000000..5a3568a
--- /dev/null
+++ b/planetstack/core/models/controlleruser.py
@@ -0,0 +1,26 @@
+import os
+import datetime
+from collections import defaultdict
+from django.db import models
+from django.db.models import F, Q
+from core.models import PlCoreBase,User,Controller
+from core.models import Controller,ControllerLinkManager,ControllerLinkDeletionManager
+
+class ControllerUsers(PlCoreBase):
+    objects = ControllerLinkManager()
+    deleted_objects = ControllerLinkDeletionManager()
+
+    user = models.ForeignKey(User,related_name='controllerusers')
+    controller = models.ForeignKey(Controller,related_name='controllersusers')
+    kuser_id = models.CharField(null=True, blank=True, max_length=200, help_text="Keystone user id")
+
+    def __unicode__(self):  return u'%s %s' % (self.controller, self.user)
+
+    @staticmethod
+    def select_by_user(user):
+        if user.is_admin:
+            qs = ControllerUsers.objects.all()
+        else:
+            users = Users.select_by_user(user)
+            qs = ControllerUsers.objects.filter(user__in=users)
+        return qs