Delete the default listener

Oct 13, 2025 by pynkocean.com 76 views

Introduction

Mosquitto is a popular open-source message broker that supports multiple protocols, including MQTT, MQTT-SN, and WebSockets. However, users have reported issues with adding additional listeners to the broker, which can lead to configuration not being persisted after a restart. In this article, we will explore the issue of additional listeners not working and mosquitto.conf not being persistent.

Symptoms

When adding an additional listener with a specific port, users encounter an error message stating that the port is already in use by the default configuration. After deleting the default listener and saving the new configuration, the additional listener is visible in the mosquitto.conf file. However, after a restart of the container, the additional listener is gone, and the default configuration is running again.

Container Logs

The container logs provide valuable information about the startup process of the Mosquitto broker and other services. The logs indicate that the broker is started successfully, and the configuration is loaded from the mosquitto.conf file.

Runtime configuration set to use host: 192.168.0.1
Firebase Auth will use proxy at http://192.168.0.1:2000/auth/
2025-03-11 07:44:45,356 INFO Set uid to user 0 succeeded
2025-03-11 07:44:45,358 INFO supervisord started with pid 1
2025-03-11 07:44:46,365 INFO spawned: 'mosquitto' with pid 34
2025-03-11 07:44:46,370 INFO spawned: 'auth-api' with pid 35
2025-03-11 07:44:46,371 INFO spawned: 'aws-bridge-api' with pid 36
2025-03-11 07:44:46,373 INFO spawned: 'azure-bridge-api' with pid 37
2025-03-11 07:44:46,374 INFO spawned: 'clientlogs' with pid 38
2025-03-11 07:44:46,376 INFO spawned: 'config-api' with pid 39
2025-03-11 07:44:46,378 INFO spawned: 'dynsec-api' with pid 40
2025-03-11 07:44:46,379 INFO spawned: 'monitor-api' with pid 41
2025-03-11 07:44:46,381 INFO spawned: 'nginx' with pid 42
2025-03-11 07:44:48,159 INFO success: mosquitto entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
2025-03-11 07:44:48,159 INFO success: auth-api entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
2025-03-11 07:44:48,159 INFO success: aws-bridge-api entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
2025-03-11 07:44:48,159 INFO success: azure-bridge-api entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
2025-03-11 07:44:48,159 INFO success: clientlogs entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
2025-03-11 07:44:48,159 INFO success: config-api entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
2025-03-11 07:44:48,159 INFO success: dynsec-api entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
2025-03-11 07:44:48,159 INFO success: monitor-api entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
2025-03-11 07:44:48,159 INFO success: nginx entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)

Broker Logs

The broker logs provide more detailed information about the Mosquitto broker's startup process and configuration loading.

2025-03-11 06:44:46 UTC	
INFO
mosquitto version 2.0.20 starting
2025-03-11 06:44:46 UTC	
INFO
Config loaded from /etc/mosquitto/mosquitto.conf.
2025-03-11 06:44:46 UTC	
INFO
Loading plugin
2025-03-11 06:44:46 UTC	
INFO
Error loading Dynamic security plugin config
2025-03-11 06:44:46 UTC	
INFO
Warning
2025-03-11 06:47:31 UTC	
INFO
To fix this, use `chmod 0700 /etc/mosquitto/mosquitto_passwd`.
2025-03-11 06:44:46 UTC	
INFO
Opening ipv4 listen socket on port 1900.
2025-03-11 06:44:46 UTC	
INFO
Opening ipv6 listen socket on port 1900.
2025-03-11 06:44:46 UTC	
INFO
Opening ipv4 listen socket on port 8080.
2025-03-11 06:44:46 UTC	
INFO
Opening ipv6 listen socket on port 8080.

Solution

To resolve the issue of additional listeners not working and mosquitto.conf not being persistent, follow these steps:

Delete the default listener: Delete the default listener with port 1900 from the Mosquitto UI.
Save the new configuration: Save the new configuration with the additional listener.
Verify the mosquitto.conf file: Verify that the additional listener is visible in the mosquitto.conf file.
Restart the container: Restart the container to test the persistence of the new configuration.
Check the broker logs: Check the broker logs to ensure that the additional listener is loaded correctly.

Conclusion

Q: What is the issue with adding additional listeners to Mosquitto?

A: The issue is that when you add an additional listener with a specific port, Mosquitto's default configuration is using the same port, resulting in a conflict. This prevents the additional listener from working correctly.

Q: How do I resolve the issue of additional listeners not working?

A: To resolve the issue, you need to delete the default listener with port 1900 from the Mosquitto UI, save the new configuration, and verify that the additional listener is visible in the mosquitto.conf file.

Q: Why is the mosquitto.conf file not being persistent after a restart?

A: The mosquitto.conf file is not being persistent after a restart because the default configuration is being loaded again, overwriting the changes made to the file.

Q: How do I ensure that the mosquitto.conf file is persistent after a restart?

A: To ensure that the mosquitto.conf file is persistent after a restart, you need to delete the default listener, save the new configuration, and verify that the additional listener is loaded correctly after a restart.

Q: What are the steps to resolve the issue of additional listeners not working and mosquitto.conf not being persistent?

A: The steps to resolve the issue are:

Delete the default listener with port 1900 from the Mosquitto UI.
Save the new configuration with the additional listener.
Verify that the additional listener is visible in the mosquitto.conf file.
Restart the container to test the persistence of the new configuration.
Check the broker logs to ensure that the additional listener is loaded correctly.

Q: What are the potential consequences of not resolving the issue of additional listeners not working and mosquitto.conf not being persistent?

A: The potential consequences of not resolving the issue are:

Inconsistent configuration: The mosquitto.conf file may not reflect the correct configuration, leading to inconsistent behavior.
Security risks: The default configuration may expose security vulnerabilities, compromising the integrity of the system.
Performance issues: The inconsistent configuration may lead to performance issues, affecting the overall system performance.

Q: How can I prevent the issue of additional listeners not working and mosquitto.conf not being persistent in the future?

A: To prevent the issue in the future, you can:

Regularly update the Mosquitto configuration to ensure that the default configuration is not using the same port as the additional listener.
Verify the persistence of the mosquitto.conf file after a restart to ensure that the changes are being saved correctly.
Monitor the broker logs to detect any issues with the configuration or the additional listener.

Conclusion

In conclusion, the issue of additional listeners not working and mosquitto.conf not being persistent can be resolved by following the steps outlined in this article. By understanding the root cause of the issue and taking proactive measures to prevent it, you can ensure that your Mosquitto broker configuration is loaded correctly and persists after a restart.