Dynamically Updating Celery Broker Password

Updating the Django settings alone won't affect the running Celery workers since they've already loaded their configuration at startup. To dynamically update the broker password without restarting, you'll need to modify the Celery app's connection settings directly.

Here's how you can implement this:

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from django.conf import settings
from celery import current_app

def refresh_celery_broker_password(new_password):
    # Update Django settings
    new_broker_url = f'redis://:{new_password}@localhost:6379/0'
    settings.CELERY_BROKER_URL = new_broker_url
    
    # Update the Celery app's broker connection
    current_app.conf.broker_url = new_broker_url
    
    # Force reconnection by closing existing connections
    current_app.pool.force_close_all()
    
    return True

Key points about this approach:

1. It updates both the Django settings and the running Celery app configuration
2. current_app refers to the currently running Celery instance
3. pool.force_close_all() ensures that new connections will use the updated broker URL

For this to work across multiple worker processes, you'll need to implement a signaling mechanism:

1. Store the new password in a shared location (database, cache)
2. Use Celery's control commands to broadcast a custom command to all workers
3. Have workers listen for this command and update their connections

For a complete solution, you might want to implement a custom Celery command and handler:

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# In your tasks.py or a dedicated module
from celery.signals import worker_ready
from celery.worker.control import Control, control_command

@control_command()
def update_broker_password(state, new_password=None):
    if new_password:
        refresh_celery_broker_password(new_password)
        return {'status': 'success', 'message': 'Broker password updated'}
    return {'status': 'error', 'message': 'No password provided'}

# To broadcast the command to all workers:
def broadcast_password_update(new_password):
    app = current_app
    app.control.broadcast('update_broker_password', arguments={'new_password': new_password})

This approach allows you to update the broker password across all workers without restarting them.