When there is not enough disk space on the agent at the beginning of the build, the
docker system prune -a command will be run cleaning the local Docker Caches. The command is run only as the last resort if all other cleaners did not manage to free enough space. Docker Disk Space Cleaner is an extension to the Free Disk Space build feature ensuring a certain amount of disk space for a build.
Since 2018.1.2 the plugin won't use
-a key to clean all data, and will use
--volumes key if it is allowed by the current docker version.
Service Message to Report Pushed Image