Executing createsuperuser with non-default database.

[Oleg Żero]

Hello!

I tried to use a different, non-default designated database for storing (auth, admin, contenttype, session), named 'users', another one for that is application-specific 'application' and 'default' is then used for everything else, like this:

...
DATABASES = {
    'default':  dj_database_url.parse(os.environ['DATABASE_OPS_URL'], conn_max_age=500), # for everything else...
    'users':     dj_database_url.parse(os.environ['DATABASE_USR_URL'], conn_max_age=500), # for auth-stuff
    'application': dj_database_url.parse(os.environ['DATABSE_APP_URL'], conn_max_age=500), # for app
}
DATABASE_ROUTERS = ['myapplication.routers.AuthRouter']
...

Following your example ​https://docs.djangoproject.com/en/2.0/topics/db/multi-db/#topics-db-multi-db-routing,
I created a router.py, in which I replicated your code.
However, being aware of the cross-database problem, my routers.py looks like this:

class AuthRouter(object):
    auth_related = (
            'auth',
            'admin',
            'contenttypes',
            'sessions',
    )

    def db_for_read(self, model, **hints):
        if model._meta.app_label in self.auth_related:
            return 'users'
        return None

    def db_for_write(self, model, **hints):
        if model._meta.app_label in self.auth_related:
            return 'users'
        return None

    def allow_relation(self, obj1, obj2, **hints):
        if obj1._meta.app_label in self.auth_related or \
           obj2._meta.app_label in self.auth_related:
            return True
        return None

    def allow_migrate(self, db, app_label, model_name=None, **hints):
        if app_label in self.auth_related:
            return db == 'users'
        return None

Then:

$ ./manage.py migrate
$ ./manage.py migrate --database=users
$ ./manage.py migrate --database=application

Works fine. I verified the database content, and yes, the tables are created in 'users'.

However, when executing:

$ ./manage.py createsuperuser

I get prompted to define the name, but just after I hit enter, I get a django.db.utils.ProgrammingError: relation "auth_user" does not exist
LINE 1: ...user"."is_active", "auth_user"."date_joined" FROM "auth_user...

...and django fails to initialize that user.
The only way I can get it to work, is when the 'users' database matches the 'default' one.
How do I work around it? Is it a bug?

Thank you very much in advance!