RabbitMQ: Existing setup with different credentials

The Problem: You changed the RabbitMQ password in your .env file, but the service is still trying to use the old password (or default guest), resulting in ACCESS_REFUSED.

1. Understanding the Cause

RabbitMQ has a specific behavior regarding Docker containers that confuses many users:

First Run: On the very first startup, RabbitMQ reads RABBITMQ_DEFAULT_USER and RABBITMQ_DEFAULT_PASS from your .env file and creates the user account in its database.
Subsequent Runs: If a database file already exists (in the Docker Volume), RabbitMQ IGNORES the .env variables. It uses the user/password already stored in the database.

Conclusion: Simply changing the .env file and restarting the container (docker compose restart) will not update the password.

2. Solution: Reset the Volume

To force RabbitMQ to accept the new password from your .env file, you must delete its old database volume so it re-initializes from scratch.

⛔ Data Loss Warning:

The steps below will delete all existing queues and messages in RabbitMQ.
This is safe for new installations or troubleshooting connectivity, but be careful in Production.

Stop Services

Stop the running containers to release the volume lock.


docker compose down

Locate & Remove the Volume

Find the volume associated with RabbitMQ and remove it.

Option A: The Clean/Automatic Way (Recommended) If you don’t mind resetting all volumes (Database, RabbitMQ, Storage):


# This removes containers AND all data volumes
docker compose down -v

Option B: The Surgical Way (RabbitMQ Only) If you want to keep other data (like PostgreSQL) and only reset RabbitMQ:


# 1. List volumes to find the exact name (look for 'rabbitmq' or 'mq')
docker volume ls
 
# 2. Remove the specific volume
docker volume rm spacedf_rabbitmq_data

(Note: Replace spacedf_rabbitmq_data with your actual volume name found in step 1).

Update `.env` & Restart

Ensure your .env has the desired credentials, then start fresh.


# 1. Check config
cat .env | grep RABBITMQ
 
# 2. Start services
docker compose up -d

RabbitMQ will see “no database file” and create a fresh user using your new .env values.

3. Alternative: Change Password via CLI (Advanced)

If you are in Production and cannot delete the volume/messages, you must use the command line to update the user manually.


# 1. Enter the running container
docker compose exec rabbitmq bash
 
# 2. Change the password manually
rabbitmqctl change_password <username> <new_password>

Replace <username> and <new_password> with the values from your .env file.

ℹ️ Key Takeaways

Stickiness: Credentials are “sticky”. RabbitMQ only reads the .env file once during the initial volume creation.
Production Safety: If you need to change passwords on a live system (Production), do NOT delete the volume. Instead, use the rabbitmqctl CLI command mentioned in Section 3 to update the password safely without losing data.
Isolation: Avoid reusing the same RabbitMQ user/password across different projects on the same server to prevent accidental cross-connection or security conflicts.