First draft of the IPAllocationLog model

coin/resources/models.py

@@ -1,4 +1,6 @@
 # -*- coding: utf-8 -*-
+import datetime
+
 from django.db import models
 from django.core.exceptions import ValidationError
 from django.core.validators import MaxValueValidator
@@ -107,3 +109,39 @@ class IPSubnet(models.Model):
 
     def __unicode__(self):
         return str(self.inet)
+
+
+class IPAllocationLog(models.Model):
+    """Tracks IP allocation for users/subscribers.  Data retention laws
+    generally impose two distincts things:
+
+    1/ Keep the data for a given duration
+
+    2/ Delete the data after this duration is expired
+
+    Besides data retention, we may also want to have an history of our IP
+    subnets.
+
+    The idea of this model is that log entries are kept forever.  However,
+    as old users and subscriptions get deleted over time, the log entries
+    will contain less and less information.  Eventually, we will just know
+    things like "such subnet was used at such time", without any idea on
+    who the user was.
+
+    """
+    # All we need to do is automatically fill this in upon other objects'
+    # creation/destruction/deactivation.
+    subnet = CidrAddressField(unique=True)
+    user = models.ForeignKey('members.Member', null=True, blank=True,
+                             on_delete=models.SET_NULL)
+    subscription = models.ForeignKey('offers.OfferSubscription', null=True,
+                                     blank=True, on_delete=models.SET_NULL)
+    offer = models.ForeignKey('offers.Offer', null=True, blank=True,
+                              on_delete=models.SET_NULL)
+    start_date = models.DateField(default=datetime.date.today)
+    stop_date = models.DateField(null=True, blank=True)
+
+    objects = NetManager()
+
+    def __unicode__(self):
+        return str(self.subnet)