AppRegistryNotReady error when "import" is in configuration.py

[Alex-Ignatov]

I am trying to follow this example add custom pollers to Validity plugin and I keep getting the error below duringdocker-compose build when I add plugin configuration that needs to import a class.. I narrowed it down to the fact that any kind of import statements in the configuration.py lead to this error. Any ideas?

from custom_pollers import ScrapliPoller
PLUGINS_CONFIG = {
    'validity': {
        'custom_pollers' : [
            {
                'class': ScrapliPoller,
                'name': 'scrapli',
                'color': 'pink',
                'command_types': ['CLI'],
            }
        ]
    }
    # ...
}

Docker build error

#26 [21/26] RUN SECRET_KEY="dummydummydummydummydummydummydummydummydummydummy" /opt/netbox/venv/bin/python /opt/netbox/netbox/manage.py collectstatic --no-input
#26 0.770 Traceback (most recent call last):
#26 0.770   File "/opt/netbox/netbox/manage.py", line 10, in <module>
#26 0.770     execute_from_command_line(sys.argv)
#26 0.770   File "/opt/netbox/venv/lib/python3.12/site-packages/django/core/management/__init__.py", line 442, in execute_from_command_line
#26 0.770 🧬 loaded config '/etc/netbox/config/configuration.py'
#26 0.770 🧬 loaded config '/etc/netbox/config/extra.py'
#26 0.770 🧬 loaded config '/etc/netbox/config/logging.py'
#26 0.770     utility.execute()
#26 0.770   File "/opt/netbox/venv/lib/python3.12/site-packages/django/core/management/__init__.py", line 382, in execute
#26 0.770     settings.INSTALLED_APPS
#26 0.770   File "/opt/netbox/venv/lib/python3.12/site-packages/django/conf/__init__.py", line 81, in __getattr__
#26 0.770     self._setup(name)
#26 0.770   File "/opt/netbox/venv/lib/python3.12/site-packages/django/conf/__init__.py", line 68, in _setup
#26 0.770     self._wrapped = Settings(settings_module)
#26 0.770                     ^^^^^^^^^^^^^^^^^^^^^^^^^
#26 0.770   File "/opt/netbox/venv/lib/python3.12/site-packages/django/conf/__init__.py", line 166, in __init__
#26 0.770     mod = importlib.import_module(self.SETTINGS_MODULE)
#26 0.770           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
#26 0.770   File "/usr/lib/python3.12/importlib/__init__.py", line 90, in import_module
#26 0.770     return _bootstrap._gcd_import(name[level:], package, level)
#26 0.770            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
#26 0.770   File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
#26 0.770   File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
#26 0.770   File "<frozen importlib._bootstrap>", line 1331, in _find_and_load_unlocked
#26 0.770   File "<frozen importlib._bootstrap>", line 935, in _load_unlocked
#26 0.770   File "<frozen importlib._bootstrap_external>", line 995, in exec_module
#26 0.770   File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
#26 0.770   File "/opt/netbox/netbox/netbox/settings.py", line 47, in <module>
#26 0.770     configuration = importlib.import_module(config_path)
#26 0.771                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
#26 0.771   File "/usr/lib/python3.12/importlib/__init__.py", line 90, in import_module
#26 0.771     return _bootstrap._gcd_import(name[level:], package, level)
#26 0.771            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
#26 0.771   File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
#26 0.771   File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
#26 0.771   File "<frozen importlib._bootstrap>", line 1331, in _find_and_load_unlocked
#26 0.771   File "<frozen importlib._bootstrap>", line 935, in _load_unlocked
#26 0.771   File "<frozen importlib._bootstrap_external>", line 995, in exec_module
#26 0.771   File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
#26 0.771   File "/opt/netbox/netbox/netbox/configuration.py", line 71, in <module>
#26 0.771     _loaded_configurations = read_configurations(
#26 0.771                              ^^^^^^^^^^^^^^^^^^^^
#26 0.771   File "/opt/netbox/netbox/netbox/configuration.py", line 55, in read_configurations
#26 0.771     _import(module_name, f.path, loaded_configurations)
#26 0.771   File "/opt/netbox/netbox/netbox/configuration.py", line 20, in _import
#26 0.771     spec.loader.exec_module(module)
#26 0.771   File "<frozen importlib._bootstrap_external>", line 995, in exec_module
#26 0.771   File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
#26 0.771   File "/etc/netbox/config/plugins.py", line 11, in <module>
#26 0.771     from custom_pollers import ScrapliPoller
#26 0.771   File "/opt/netbox/venv/lib/python3.12/site-packages/custom_pollers/__init__.py", line 5, in <module>
#26 0.771     from .custom_pollers import ScrapliPoller
#26 0.771   File "/opt/netbox/venv/lib/python3.12/site-packages/custom_pollers/custom_pollers.py", line 2, in <module>
#26 0.771     from validity.pollers import CustomPoller
#26 0.771   File "/opt/netbox/venv/lib/python3.12/site-packages/validity/pollers/__init__.py", line 3, in <module>
#26 0.771     from .http import RequestsPoller
#26 0.771   File "/opt/netbox/venv/lib/python3.12/site-packages/validity/pollers/http.py", line 4, in <module>
#26 0.771     from dcim.models import Device
#26 0.771   File "/opt/netbox/netbox/dcim/models/__init__.py", line 1, in <module>
#26 0.771     from .cables import *
#26 0.772   File "/opt/netbox/netbox/dcim/models/cables.py", line 3, in <module>
#26 0.772     from django.contrib.contenttypes.fields import GenericForeignKey
#26 0.772   File "/opt/netbox/venv/lib/python3.12/site-packages/django/contrib/contenttypes/fields.py", line 8, in <module>
#26 0.772     from django.contrib.contenttypes.models import ContentType
#26 0.772   File "/opt/netbox/venv/lib/python3.12/site-packages/django/contrib/contenttypes/models.py", line 134, in <module>
#26 0.772     class ContentType(models.Model):
#26 0.772   File "/opt/netbox/venv/lib/python3.12/site-packages/django/db/models/base.py", line 131, in __new__
#26 0.772     app_config = apps.get_containing_app_config(module)
#26 0.772                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
#26 0.772   File "/opt/netbox/venv/lib/python3.12/site-packages/django/apps/registry.py", line 260, in get_containing_app_config
#26 0.772     self.check_apps_ready()
#26 0.772   File "/opt/netbox/venv/lib/python3.12/site-packages/django/apps/registry.py", line 138, in check_apps_ready
#26 0.773     raise AppRegistryNotReady("Apps aren't loaded yet.")
#26 0.773 django.core.exceptions.AppRegistryNotReady: Apps aren't loaded yet

[tobiasge]

I'm guessing that ScrapliPoller is a class that is in some way inheriting from the Django model class. In Django you can't import model classes before the system is initialised. This includes the settings.py (or in this case configuration.py), app.py, wsgi.py and so on.
I'm not sure how this iss supposed to work in that plugin, but you probably need to use the full dotted class name as a string instead of the imported class.

[Alex-Ignatov]

Ahh, makes sense. Thank you for checking!

When I try with dotted class name I get:

1.879 pydantic_core._pydantic_core.ValidationError: 1 validation error for ValiditySettings
1.879 custom_pollers.0.class
1.879   Input should be a subclass of BasePoller [type=is_subclass_of, input_value='custom_pollers.ScrapliPoller', input_type=str]
1.879     For further information visit https://errors.pydantic.dev/2.11/v/is_subclass_of

I guess I need to check with the plugin developer on this one..