run the container as a non root user (some containers won’t work so they need to be run as root user)
To avoid issues with containers, could also make use of user namespaces: https://docs.docker.com/engine/security/userns-remap/
Allows a process to have root privileges within the container, but be unprivileged on the host.
I’d argue it’s up there :) In the end you’re quite limited with what you can do as an unprivileged user.
Granted it’s not for Docker, but Kubernetes, but userns is userns. This Kubernetes blog post even has a short demo :) https://kubernetes.io/blog/2023/09/13/userns-alpha/