gem-hunter
Language: Python
Proper INET and CIDR fields for Django running on PostgreSQL
This project is an attempt at making proper PostgreSQL net related fields for
Django. In Django pre 1.4 the built in IPAddressField does not support IPv6
and uses an inefficient HOST() cast in all lookups. As of 1.4 you can use
GenericIPAddressField for IPv6, but the casting problem remains.
In addition to the basic IPAddressField replacement, InetAddressField,
a CidrAddressField a MACAddressField, and a MACAddress8Field have
been added. This library also provides a manager that allows for advanced IP
based lookups directly in the ORM.
In Python, the values of the IP address fields are represented as types from the ipaddress module. In Python 2.x, a backport is used. The MAC address fields are represented as EUI types from the netaddr module.
This module requires Django >= 1.11, psycopg2 or psycopg, and netaddr.
$ pip install django-netfields
Make sure netfields is in your PYTHONPATH and in INSTALLED_APPS.
InetAddressField will store values in PostgreSQL as type INET. In
Python, the value will be represented as an ipaddress.ip_interface object
representing an IP address and netmask/prefix length pair unless the
store_prefix_length argument is set to False, in which case the value
will be represented as an ipaddress.ip_address object.
from netfields import InetAddressField, NetManager class Example(models.Model): inet = InetAddressField() # ... objects = NetManager()
CidrAddressField will store values in PostgreSQL as type CIDR. In
Python, the value will be represented as an ipaddress.ip_network object.
from netfields import CidrAddressField, NetManager class Example(models.Model): inet = CidrAddressField() # ... objects = NetManager()
MACAddressField will store values in PostgreSQL as type MACADDR. In
Python, the value will be represented as a netaddr.EUI object. Note that
the default text representation of EUI objects is not the same as that of the
netaddr module. It is represented in a format that is more commonly used
in network utilities and by network administrators (00:11:22:aa:bb:cc).
from netfields import MACAddressField, NetManager class Example(models.Model): inet = MACAddressField() # ...
MACAddress8Field will store values in PostgreSQL as type MACADDR8. In
Python, the value will be represented as a netaddr.EUI object. As with
MACAddressField, the representation is the common one
(00:11:22:aa:bb:cc:dd:ee).
from netfields import MACAddress8Field, NetManager class Example(models.Model): inet = MACAddress8Field() # ...
For InetAddressField and CidrAddressField, NetManager is required
for the extra lookups to be available. Lookups for INET and CIDR
database types will be handled differently than when running vanilla Django.
All lookups are case-insensitive and text based lookups are avoided whenever
possible. In addition to Django's default lookup types the following have been
added:
__net_contained__net_contained_or_equal__net_contains__net_contains_or_equals__net_overlaps__family__host__prefixlenThese correspond with the operators and functions from http://www.postgresql.org/docs/9.4/interactive/functions-net.html
CidrAddressField includes two extra lookups (these will be depreciated in the future by __prefixlen):
__max_prefixlenCIDR prefix, does not distinguish between IPv4 and IPv6__min_prefixlenCIDR prefix, does not distinguish between IPv4 and IPv6Postgres network address functions are exposed via the netfields.functions module. They can be used to extract additional information from these fields or to construct complex queries.
from django.db.models import F from netfields import CidrAddressField, NetManager from netfields.functions import Family, Masklen class Example(models.Model): inet = CidrAddressField() # ... ipv4_with_num_ips = ( Example.objects.annotate( family=Family(F('inet')), num_ips=2 ** (32 - Masklen(F('inet'))) # requires Django >2.0 to resolve ) .filter(family=4) )
CidrAddressField and InetAddressField Functions
| Postgres Function | Django Function | Return Type | Description |
|---|---|---|---|
abbrev(T) |
Abbrev | TextField |
abbreviated display format as text |
broadcast(T) |
Broadcast | InetAddressField |
broadcast address for network |
family(T) |
Family | IntegerField |
extract family of address; 4 for IPv4, 6 for IPv6 |
host(T) |
Host | TextField |
extract IP address as text |
hostmask(T) |
Hostmask | InetAddressField |
construct host mask for network |
masklen(T) |
Masklen | IntegerField |
extract netmask length |
netmask(T) |
Netmask | InetAddressField |
construct netmask for network |
network(T) |
Network | CidrAddressField |
extract network part of address |
set_masklen(T, int) |
SetMasklen | T |
set netmask length for inet value |
text(T) |
AsText | TextField |
extract IP address and netmask length as text |
inet_same_family(T, T) |
IsSameFamily | BooleanField |
are the addresses from the same family? |
inet_merge(T, T) |
Merge | CidrAddressField |
the smallest network which includes both of the given networks |
MACAddressField Functions
| Postgres Function | Django Function | Return Type | Description |
|---|---|---|---|
trunc(T) |
Trunc | T |
set last 3 bytes to zero |
MACAddress8Field Functions
| Postgres Function | Django Function | Return Type | Description |
|---|---|---|---|
trunc(T) |
Trunc | T |
set last 5 bytes to zero |
macaddr8_set7bit(T) |
Macaddr8Set7bit | T |
set 7th bit to one. Used to generate link-local IPv6 addresses |
As of Django 2.2, indexes can be created for InetAddressField and CidrAddressField extra lookups directly on the model.
from django.contrib.postgres.indexes import GistIndex from netfields import CidrAddressField, NetManager class Example(models.Model): inet = CidrAddressField() # ... class Meta: indexes = ( GistIndex( fields=('inet',), opclasses=('inet_ops',), name='app_example_inet_idx' ), )
For earlier versions of Django, a custom migration can be used to install an index.
from django.db import migrations class Migration(migrations.Migration): # ... operations = [ # ... migrations.RunSQL( "CREATE INDEX app_example_inet_idx ON app_example USING GIST (inet inet_ops);" ), # ... ]
https://docs.djangoproject.com/en/dev/releases/1.4/#extended-ipv6-support is also relevant
https://bitbucket.org/onelson/django-ipyfield tries to solve some of the same
issues as this library. However, instead of supporting just postgres via the proper
fields types the ipyfield currently uses a VARCHAR(39) as a fake unsigned 64 bit
number in its implementation.
Main repo was originally kept https://github.com/adamcik/django-postgresql-netfields Late April 2013 the project was moved to https://github.com/jimfunk/django-postgresql-netfields to pass the torch on to someone who actually uses this code actively :-)