If the goal is just preventing full root privileges, a CapabilityBoundingSet in a systemd unit will do.
However copy fail can be used in many other ways not contained by containers or the above settings. For example it can modify the /etc/ssl/certs to prepare for MitM attacks. If you have multiple containers based on the same image then one compromised CA set affects another.
However copy fail can be used in many other ways not contained by containers or the above settings. For example it can modify the /etc/ssl/certs to prepare for MitM attacks. If you have multiple containers based on the same image then one compromised CA set affects another.