Programmatically creating a group : Can't access permissions from migration

Question

After seeing this post, I tried to create my own group at project setup with this migration :

from django.db import migrations
from django.contrib.auth.model         


        

Answer 1

Permissions are created in a post_migrate signal. They don't exist the first time migrations are run after a new model is added. It is probably easiest to run the post_migrate signal handler manually:

from django.contrib.auth.management import create_permissions

def create_group(apps, schema_editor):
    for app_config in apps.get_app_configs():
        create_permissions(app_config, apps=apps, verbosity=0)

    group, created = Group.objects.get_or_create(name='thing_managers')
    if created:
        add_thing = Permission.objects.get(codename='add_thing')
        group.permissions.add(add_thing)
        group.save()

create_permissions checks for existing permissions, so this won't create any duplicates.