I want to automatically cleanup all unused docker resources in order to release more disk space for next ci jobs. Therefore, I created a cron job to cleanup unused docker resources every 5 mins. My docker cleanup script is
sudo docker system prune --all --volumes --force
However, this cron job may mis-delete images which will be used later. For example, delete intermediate container images while docker build and lead to error unknown parent image ID.
Periodic cleanup doesn’t seem to be a good practice. The better practice to me is execute docker cleanup script before/after gitlab runner executes a ci job.
To achieve this, I can set cleanup script in pre_build_script or post_build_script in gitlab runner. But, ci environment (container image) that executes build scripts is vary with ci job. The cleanup script may be incompatible with every os. pre_build_script and post_build_script are not suitable in my case.
Is there any approach to detect when gitlab runner starts to run a ci job? Or any better solutions to cleanup unused docker resources for every ci job?
Run docker-cleanup container as Runner CI service
I run a docker-cleanup container as CI service for each CI Job. My CI service is created in the beginning of CI Job and clean up unused docker resources. Problem solved!
Config.toml
Docker-cleanup Dockerfile
It’s better to use
filterindocker system pruneto avoid mis-deleting images