Add support for custom container user permissions via PUID and PGID
environment variables. When the container is started as root
(--user root), the pgadmin user is reassigned to the requested UID/GID
and all initialization runs under that user via su-exec, ensuring
files are created with correct ownership from the start.
Key changes:
- Dockerfile: add su-exec package, add chmod g=u for /run/pgadmin
(fixes OpenShift random UID access)
- entrypoint.sh: add PUID/PGID validation and privilege dropping
before initialization (not after), preserving OpenShift compatibility
Three modes supported:
- Default (USER 5050): unchanged behavior
- Custom UID (--user root -e PUID=N -e PGID=N): drops to target user
before any init
- OpenShift (random UID, GID 0): passwd fixup + group permissions
4ddb16f47a