Adding django admin permissions in a migration: Permission matching query does not exist

Question

I wanted to add some groups and assign permissions to them in a manually written migration but if I run it on a clean DB it creates permissions only after running all migrations.

I've found this ticket: https://code.djangoproject.com/ticket/23422 but I cannot comment there (it's possible I was banned after expressing some discontent with GeoDjango docs), so I'll share an improvement over the solution there below.

Answer 1

In django 1.10 the following code could be used:

from django.contrib.auth.management import create_permissions

def migrate_permissions(apps, schema_editor):
    for app_config in apps.get_app_configs():
        app_config.models_module = True
        create_permissions(app_config, apps=apps, verbosity=0)
        app_config.models_module = None

Answer 2

Django <= 1.9

see another answer for Django 1.10+

It's enough to call create_permissions:

from django.contrib.auth.management import create_permissions

apps.models_module = True
create_permissions(apps, verbosity=0)
apps.models_module = None

The whole migration being something like this

# coding:utf-8
from django.db import migrations
from django.contrib.auth.models import Permission, Group
from django.contrib.auth.management import create_permissions
from django.contrib.contenttypes.models import ContentType
from django.conf import settings

MODERATORS_PERMISSIONS = ['change_modelname', ]


def add_permissions(apps, schema_editor):
    apps.models_module = True
    create_permissions(apps, verbosity=0)
    apps.models_module = None

    moderators_group = Group.objects.get_or_create(
        name=settings.MODERATORS_GROUP)[0]
    for codename in MODERATORS_PERMISSIONS:
        permission = Permission.objects.get(codename=codename)
        moderators_group.permissions.add(permission)


class Migration(migrations.Migration):

    dependencies = [
        ('contenttypes', '0002_remove_content_type_name'),
        ('thisappname', '0001_initial'),
    ]

    operations = [
        migrations.RunPython(add_permissions),
    ]