kpsul/bds/apps.py

from django.apps import AppConfig
from django.db.models.signals import post_migrate


def setup_groups(sender, apps, **kwargs):
    """
    Add the appropriate permissions to the "member" and "buro" groups after the
    `post_migrate` signal since the permissions will only be inserted in the
    database at the very end of the migrations.
    """
    Group = apps.get_model("auth", "Group")
    Permission = apps.get_model("auth", "Permission")

    # Buro members have perms bds.* and gestion.*
    buro, _ = Group.objects.get_or_create(name="bds_buro")
    app_perms = Permission.objects.filter(
        content_type__app_label__in=["cof", "gestion"]
    )
    buro.permissions.add(*app_perms)

    # Members have perm bds.member
    members, _ = Group.objects.get_or_create(name="bds_members")
    perm = Permission.objects.get(
        codename="member",
        content_type__app_label="bds"
    )
    members.permissions.add(perm)


class BDSConfig(AppConfig):
    name = "bds"
    verbose_name = "Application de gestion du BDS"

    def ready(self):
        # https://docs.djangoproject.com/en/1.11/ref/signals/#post-migrate
        post_migrate.connect(setup_groups, sender=self)