I'm trying to build a data container to ship developer databases (up to date migrations, fixture data, etc which are managed elsewhere). We could use a docker-entrypoint-initdb.d script to move a bundled data folder to PGDATA (similar to what's suggested in #105), but then the entire initdb process was a (one time) waste.

I'm proposing a new USE_SEED_DB env var that would skip initdb and instead move everything in a "seed" directory to PGDATA. This would set the expectation that scripts in docker-entrypoint-initdb.d/ would act on the seed db and not a fresh one.

I'm willing to submit a PR for this.