One proposed question for the M2 checklist is:

• Have all project containers been designed to run as a non-root user?

PTLs: please provide the impact this requirement will have your project in the comments section of this Jira.

It is clear that Docker engine will run as root.

We strongly recommend that for projects that require to run their container as root, justification would be provided by PTL.  

For tests for docker container - script to be provided by Krzysztof.