Docker Engine Docker: Error response from daemon: failed to remove config

What is Docker Engine Docker: Error response from daemon: failed to remove config

Understanding Docker Engine

Docker Engine is a containerization technology that allows developers to automate the deployment of applications inside lightweight, portable containers. It provides a robust platform for building, shipping, and running distributed applications, whether on laptops, data center VMs, or the cloud.

Identifying the Symptom

When working with Docker, you might encounter the following error message: Docker: Error response from daemon: failed to remove config. This error typically occurs when you attempt to remove a Docker config that is still in use.

What is a Docker Config?

A Docker config is a mechanism to securely store and manage configuration data separately from the application code. This allows for more flexible and secure application deployments.

Explaining the Issue

The error message indicates that the Docker config you are trying to remove is currently being used by one or more services. Docker prevents the removal of configs that are in use to ensure that services relying on them do not break unexpectedly.

Why Does This Happen?

This issue arises because Docker maintains a reference count for configs. If a config is referenced by any running service, Docker will not allow its removal until all references are cleared.

Steps to Resolve the Issue

To resolve this issue, you need to identify and stop the services using the config before attempting to remove it.

Step 1: Identify Services Using the Config

Use the following command to list all services and identify which ones are using the config:

docker service ls --filter config=

Replace <config_name> with the name of your config.

Step 2: Remove or Update Services

Once you have identified the services, you can either remove or update them to no longer use the config. To remove a service, use:

docker service rm

To update a service to stop using the config, use:

docker service update --config-rm

Step 3: Remove the Config

After ensuring no services are using the config, you can safely remove it with:

docker config rm

Additional Resources

For more information on Docker configs, you can refer to the official Docker documentation. If you encounter further issues, consider visiting the Docker Community Forums for additional support.