ModuleNotFoundError: No module named 'users' from dj-rest-auth - python-3.x

Question

I am trying to run celery on a Django application that has dj-rest-auth already configured but, I get the following error when I run - "celery -A config worker -l info" but, it works perfectly fine without errors when I do "python manage.py runserver".
The application has several apps under the folder /apps and within the settings.py, it is imported as "apps.<app_name>". It does have an app called "users" so, it's imported as "apps.users".
Traceback (most recent call last):
File "/usr/local/bin/celery", line 8, in <module>
sys.exit(main())
File "/usr/local/lib/python3.10/site-packages/celery/__main__.py", line 15, in main
sys.exit(_main())
File "/usr/local/lib/python3.10/site-packages/celery/bin/celery.py", line 213, in main
return celery(auto_envvar_prefix="CELERY")
File "/usr/local/lib/python3.10/site-packages/click/core.py", line 1128, in __call__
return self.main(*args, **kwargs)
File "/usr/local/lib/python3.10/site-packages/click/core.py", line 1053, in main
rv = self.invoke(ctx)
File "/usr/local/lib/python3.10/site-packages/click/core.py", line 1659, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/usr/local/lib/python3.10/site-packages/click/core.py", line 1395, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/usr/local/lib/python3.10/site-packages/click/core.py", line 754, in invoke
return __callback(*args, **kwargs)
File "/usr/local/lib/python3.10/site-packages/click/decorators.py", line 26, in new_func
return f(get_current_context(), *args, **kwargs)
File "/usr/local/lib/python3.10/site-packages/celery/bin/base.py", line 134, in caller
return f(ctx, *args, **kwargs)
File "/usr/local/lib/python3.10/site-packages/celery/bin/worker.py", line 343, in worker
worker = app.Worker(
File "/usr/local/lib/python3.10/site-packages/celery/worker/worker.py", line 94, in __init__
self.app.loader.init_worker()
File "/usr/local/lib/python3.10/site-packages/celery/loaders/base.py", line 111, in init_worker
self.import_default_modules()
File "/usr/local/lib/python3.10/site-packages/celery/loaders/base.py", line 105, in import_default_modules
raise response
File "/usr/local/lib/python3.10/site-packages/celery/utils/dispatch/signal.py", line 276, in send
response = receiver(signal=self, sender=sender, **named)
File "/usr/local/lib/python3.10/site-packages/celery/fixups/django.py", line 82, in on_import_modules
self.worker_fixup.validate_models()
File "/usr/local/lib/python3.10/site-packages/celery/fixups/django.py", line 121, in validate_models
run_checks()
File "/usr/local/lib/python3.10/site-packages/django/core/checks/registry.py", line 76, in run_checks
new_errors = check(app_configs=app_configs, databases=databases)
File "/usr/local/lib/python3.10/site-packages/django/core/checks/urls.py", line 13, in check_url_config
return check_resolver(resolver)
File "/usr/local/lib/python3.10/site-packages/django/core/checks/urls.py", line 23, in check_resolver
return check_method()
File "/usr/local/lib/python3.10/site-packages/django/urls/resolvers.py", line 412, in check
for pattern in self.url_patterns:
File "/usr/local/lib/python3.10/site-packages/django/utils/functional.py", line 48, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "/usr/local/lib/python3.10/site-packages/django/urls/resolvers.py", line 598, in url_patterns
patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
File "/usr/local/lib/python3.10/site-packages/django/utils/functional.py", line 48, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "/usr/local/lib/python3.10/site-packages/django/urls/resolvers.py", line 591, in urlconf_module
return import_module(self.urlconf_name)
File "/usr/local/lib/python3.10/importlib/__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 883, in exec_module
File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
File "/app/config/urls.py", line 13, in <module>
path("api/v1/auth/", include("dj_rest_auth.urls")),
File "/usr/local/lib/python3.10/site-packages/django/urls/conf.py", line 34, in include
urlconf_module = import_module(urlconf_module)
File "/usr/local/lib/python3.10/importlib/__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 883, in exec_module
File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
File "/usr/local/lib/python3.10/site-packages/dj_rest_auth/urls.py", line 4, in <module>
from dj_rest_auth.views import (
File "/usr/local/lib/python3.10/site-packages/dj_rest_auth/views.py", line 16, in <module>
from .app_settings import (
File "/usr/local/lib/python3.10/site-packages/dj_rest_auth/app_settings.py", line 35, in <module>
UserDetailsSerializer = import_callable(serializers.get('USER_DETAILS_SERIALIZER', DefaultUserDetailsSerializer))
File "/usr/local/lib/python3.10/site-packages/dj_rest_auth/utils.py", line 12, in import_callable
return getattr(import_module(package), attr)
File "/usr/local/lib/python3.10/importlib/__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
ModuleNotFoundError: No module named 'users'
root#1a45d3d56ced:/app# celery -A config worker -l info
DEBUG 2021-12-09 11:36:44,651 base 132 140186677212992 Configuring Raven for host: None
INFO 2021-12-09 11:36:44,652 base 132 140186677212992 Raven is not configured (logging is disabled). Please see the documentation for more information.
Traceback (most recent call last):
File "/usr/local/bin/celery", line 8, in <module>
sys.exit(main())
File "/usr/local/lib/python3.10/site-packages/celery/__main__.py", line 15, in main
sys.exit(_main())
File "/usr/local/lib/python3.10/site-packages/celery/bin/celery.py", line 213, in main
return celery(auto_envvar_prefix="CELERY")
File "/usr/local/lib/python3.10/site-packages/click/core.py", line 1128, in __call__
return self.main(*args, **kwargs)
File "/usr/local/lib/python3.10/site-packages/click/core.py", line 1053, in main
rv = self.invoke(ctx)
File "/usr/local/lib/python3.10/site-packages/click/core.py", line 1659, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/usr/local/lib/python3.10/site-packages/click/core.py", line 1395, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/usr/local/lib/python3.10/site-packages/click/core.py", line 754, in invoke
return __callback(*args, **kwargs)
File "/usr/local/lib/python3.10/site-packages/click/decorators.py", line 26, in new_func
return f(get_current_context(), *args, **kwargs)
File "/usr/local/lib/python3.10/site-packages/celery/bin/base.py", line 134, in caller
return f(ctx, *args, **kwargs)
File "/usr/local/lib/python3.10/site-packages/celery/bin/worker.py", line 343, in worker
worker = app.Worker(
File "/usr/local/lib/python3.10/site-packages/celery/worker/worker.py", line 94, in __init__
self.app.loader.init_worker()
File "/usr/local/lib/python3.10/site-packages/celery/loaders/base.py", line 111, in init_worker
self.import_default_modules()
File "/usr/local/lib/python3.10/site-packages/celery/loaders/base.py", line 105, in import_default_modules
raise response
File "/usr/local/lib/python3.10/site-packages/celery/utils/dispatch/signal.py", line 276, in send
response = receiver(signal=self, sender=sender, **named)
File "/usr/local/lib/python3.10/site-packages/celery/fixups/django.py", line 82, in on_import_modules
self.worker_fixup.validate_models()
File "/usr/local/lib/python3.10/site-packages/celery/fixups/django.py", line 121, in validate_models
run_checks()
File "/usr/local/lib/python3.10/site-packages/django/core/checks/registry.py", line 76, in run_checks
new_errors = check(app_configs=app_configs, databases=databases)
File "/usr/local/lib/python3.10/site-packages/django/core/checks/urls.py", line 13, in check_url_config
return check_resolver(resolver)
File "/usr/local/lib/python3.10/site-packages/django/core/checks/urls.py", line 23, in check_resolver
return check_method()
File "/usr/local/lib/python3.10/site-packages/django/urls/resolvers.py", line 412, in check
for pattern in self.url_patterns:
File "/usr/local/lib/python3.10/site-packages/django/utils/functional.py", line 48, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "/usr/local/lib/python3.10/site-packages/django/urls/resolvers.py", line 598, in url_patterns
patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
File "/usr/local/lib/python3.10/site-packages/django/utils/functional.py", line 48, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "/usr/local/lib/python3.10/site-packages/django/urls/resolvers.py", line 591, in urlconf_module
return import_module(self.urlconf_name)
File "/usr/local/lib/python3.10/importlib/__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 883, in exec_module
File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
File "/app/config/urls.py", line 13, in <module>
path("api/v1/auth/", include("dj_rest_auth.urls")),
File "/usr/local/lib/python3.10/site-packages/django/urls/conf.py", line 34, in include
urlconf_module = import_module(urlconf_module)
File "/usr/local/lib/python3.10/importlib/__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 883, in exec_module
File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
File "/usr/local/lib/python3.10/site-packages/dj_rest_auth/urls.py", line 4, in <module>
from dj_rest_auth.views import (
File "/usr/local/lib/python3.10/site-packages/dj_rest_auth/views.py", line 16, in <module>
from .app_settings import (
File "/usr/local/lib/python3.10/site-packages/dj_rest_auth/app_settings.py", line 35, in <module>
UserDetailsSerializer = import_callable(serializers.get('USER_DETAILS_SERIALIZER', DefaultUserDetailsSerializer))
File "/usr/local/lib/python3.10/site-packages/dj_rest_auth/utils.py", line 12, in import_callable
return getattr(import_module(package), attr)
File "/usr/local/lib/python3.10/importlib/__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
ModuleNotFoundError: No module named 'users'

Answer 1

We faced the same problem. The imports in this case include the module specification strings from settings.py, not just the import statements at the top of the modules. In our case this was the fix
REST_AUTH_SERIALIZERS = {
- "LOGIN_SERIALIZER": "users.api.serializers.LoginSerializer",
+ "LOGIN_SERIALIZER": "<app_name>.users.api.serializers.LoginSerializer",
}