sonatype/docker-nexus3 ? reverse-engineered prompt

Build me a Dockerized Nexus Repository Manager 3 setup that I can run locally or on a server.

I want a simple image and compose setup that starts on port 8081, uses persistent storage for config, logs, and binaries, and gives me the default admin login flow with the generated password saved in the data volume. It should be easy to build from source, and I’d like clear support for the main image plus the Alpine based default and a UBI option if needed. Please make sure the container starts with the right permissions for the Nexus user and works cleanly with a mounted data directory.

If there are helpful scripts for building or testing the image, include those too. Keep it practical and ready to use, and look up current docs online if you need to confirm any Nexus specifics.