How to set up automatic cleanup of unused images and containers using Docker System Prune on a schedule?

Over time, Docker accumulates a large number of stopped containers, unused networks, volumes, and outdated images, which can completely take up the free disk space on the server. Manually running cleanup commands helps solve the problem temporarily, but keeping the system clean on an ongoing basis requires automation.

The simplest way to regularly clean up is to create a task in the cron system scheduler on the host machine. To do this, you need to open the task table editor using a special command and add a line that will call the full system cleanup command with automatic deletion confirmation flags.

When setting up automatic deletion, it is important to be careful not to accidentally delete necessary data. The flag for deleting all unused containers and images is useful on test servers, but on production, it can erase stopped service backups. Therefore, it is recommended to use creation time filters or explicitly specify objects for deletion.

For more advanced data lifecycle management, it is better to use labels and custom automation scripts. Such scripts can check the status of running applications and delete only those images that have not been used for a specified number of days, minimizing the risks of disruptions in production services.