Docker container scanning in gitlab

I need to setup docker container scanning using clair in gitlab, could someone help me how to do this

Since Clair is designed to be running as service somewhere and not designed to run new Clair instance with every pipeline I am expecting that you have it deployed and running somewhere and it is accessible from GitLab Runner. In such case you can use clairctl within your job to tell Clair what to do.

Anyway, GitLab Container Scanning will be moved to Core (free) with GitLab 15.0 which is planned for May 22.

I am new to this, can you please help me with the basic docker file and yml file just to scan using one image container and see the results. I’ve gone through the documentation but confused finally