netbox/netbox/extras/apps.py

from django.apps import AppConfig
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
import redis


class ExtrasConfig(AppConfig):
    name = "extras"

    def ready(self):

        import extras.signals

        # Check that we can connect to the configured Redis database.
        try:
            rs = redis.Redis(
                host=settings.WEBHOOKS_REDIS_HOST,
                port=settings.WEBHOOKS_REDIS_PORT,
                db=settings.WEBHOOKS_REDIS_DATABASE,
                password=settings.WEBHOOKS_REDIS_PASSWORD or None,
                ssl=settings.WEBHOOKS_REDIS_SSL,
            )
            rs.ping()
        except redis.exceptions.ConnectionError:
            raise ImproperlyConfigured(
                "Unable to connect to the Redis database. Check that the Redis configuration has been defined in "
                "configuration.py."
            )