ModuleNotFoundError: No module named 'rest_framework' when running celery -A backend worker -l info

Question

I'm trying to run my tasks and I'm currently using Celery for this alongside Django and DjangoRestFramework

This is how I've set things up, root directory is also called backend

.
├── backend
│   ├── asgi.py
│   ├── celery.py
│   ├── settings.py
│   ├── urls.py
│   └── wsgi.py
├── db.sqlite3
├── manage.py
└── save_to_db
    ├── admin.py
    ├── apps.py
    ├── dump.rdb
    ├── migrations
    │   ├── 0001_initial.py
    │   └── 0002_auto_20210728_0251.py
    ├── models.py
    ├── serializers.py
    ├── tasks.py
    ├── tests.py
    ├── urls.py
    └── views.py

So I have all my configuration for Celery in celery.py which I followed from this on how to set up Celery for Django https://docs.celeryproject.org/en/stable/django/first-steps-with-django.html This is how my config looks like

import os

from celery import Celery

# Set the default Django settings module for the 'celery' program.
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'backend.settings')

app = Celery('backend')

# Using a string here means the worker doesn't have to serialize
# the configuration object to child processes.
# - namespace='CELERY' means all celery-related configuration keys
#   should have a `CELERY_` prefix.
app.config_from_object('django.conf:settings', namespace='CELERY')

# Load task modules from all registered Django apps.
app.autodiscover_tasks()


@app.task(bind=True)
def debug_task(self):
    print(f'Request: {self.request!r}')

I decided to run this command to get Celery started celery -A backend worker -l info

But this gives me this error

Traceback (most recent call last):
  File "/usr/local/bin/celery", line 8, in <module>
    sys.exit(main())
  File "/usr/local/lib/python3.9/site-packages/celery/__main__.py", line 15, in main
    sys.exit(_main())
  File "/usr/local/lib/python3.9/site-packages/celery/bin/celery.py", line 213, in main
    return celery(auto_envvar_prefix="CELERY")
  File "/usr/local/lib/python3.9/site-packages/click/core.py", line 829, in __call__
    return self.main(*args, **kwargs)
  File "/usr/local/lib/python3.9/site-packages/click/core.py", line 782, in main
    rv = self.invoke(ctx)
  File "/usr/local/lib/python3.9/site-packages/click/core.py", line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/local/lib/python3.9/site-packages/click/core.py", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/local/lib/python3.9/site-packages/click/core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "/usr/local/lib/python3.9/site-packages/click/decorators.py", line 21, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/usr/local/lib/python3.9/site-packages/celery/bin/base.py", line 133, in caller
    return f(ctx, *args, **kwargs)
  File "/usr/local/lib/python3.9/site-packages/celery/bin/worker.py", line 338, in worker
    worker = app.Worker(
  File "/usr/local/lib/python3.9/site-packages/celery/worker/worker.py", line 94, in __init__
    self.app.loader.init_worker()
  File "/usr/local/lib/python3.9/site-packages/celery/loaders/base.py", line 111, in init_worker
    self.import_default_modules()
  File "/usr/local/lib/python3.9/site-packages/celery/loaders/base.py", line 105, in import_default_modules
    raise response
  File "/usr/local/lib/python3.9/site-packages/celery/utils/dispatch/signal.py", line 276, in send
    response = receiver(signal=self, sender=sender, **named)
  File "/usr/local/lib/python3.9/site-packages/celery/fixups/django.py", line 82, in on_import_modules
    self.worker_fixup.validate_models()
  File "/usr/local/lib/python3.9/site-packages/celery/fixups/django.py", line 120, in validate_models
    self.django_setup()
  File "/usr/local/lib/python3.9/site-packages/celery/fixups/django.py", line 116, in django_setup
    django.setup()
  File "/usr/local/lib/python3.9/site-packages/django/__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/usr/local/lib/python3.9/site-packages/django/apps/registry.py", line 91, in populate
    app_config = AppConfig.create(entry)
  File "/usr/local/lib/python3.9/site-packages/django/apps/config.py", line 224, in create
    import_module(entry)
  File "/usr/local/Cellar/python@3.9/3.9.4/Frameworks/Python.framework/Versions/3.9/lib/python3.9/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
  File "<frozen importlib._bootstrap>", line 984, in _find_and_load_unlocked
ModuleNotFoundError: No module named 'rest_framework'

I have installed DjangoRestFramework via Poetry and it shows up in my pyproject.toml and I've include rest_framework in my INSTALLED_APPS in settings

Installed apps and some other config for celery in my settings.py

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'rest_framework',
    'save_to_db'
]

# Celery Configuration Options
CELERY_TIMEZONE = "US/Eastern"
CELERY_TASK_TRACK_STARTED = True

# CELERY STUFF
BROKER_URL = 'redis://localhost:6379'
CELERY_RESULT_BACKEND = 'redis://localhost:6379'
CELERY_ACCEPT_CONTENT = ['application/json']
CELERY_TASK_SERIALIZER = 'json'
CELERY_RESULT_SERIALIZER = 'json'

Answer 1

Is your project running on virtual environment? If so run celery within virtual environment.

Answer 2

I ran in the same issus, for me i installed djangorestframework after building the container thats why i didnt recongnize it after a run the container again. so what i did is i added the djangorestframework to my requirments.txt and rebuild the image from scratch