Hi Manuel,
good to know that you are willing to provide your contributions to the gerrit-installer project :-)
The overall idea of Docker images is to:
a) Provide a "common ground" to all derived Dockerfiles created and contributed to the community
b) Give a "plug&play" configuration (exactly the same used in the native packages) to be used as bootstrap test
c) Allow derived Docker images with production-ready DB and FS configurations (yours for instance)
Can you submit your Dockerfile to the gerrit-installer project for review?
Thank you for your contribution and input :-)
Luca.