Postgres Docker importing SQL dump on docker build - database

Question

I'm trying to get rid of Docker-In-Docker, therefore I'm replacing our Postgres images with new ones. For a use case we use a pre-filled Postgres image. The old workflow is to build the image, pull it in a pipeline and use Docker-In-Docker to fill it with data, then re-upload it to the Image registry again.
The new approach is to create the Postgres image with docker, and I've copied the .sql Dumps to /docker-entrypoint-initdb.d/. But this fills the image after the startup, I'd like to have a pre-filled image in the container registry because the filling takes up to 2 minutes.
This is my Dockerfile:
FROM postgres:11.12
LABEL maintainer="Hello Stackoverflow"
ARG POSTGRES_VERSION="11.12"
ARG TZ="Europe/Berlin"
ENV TZ ${TZ}
ENV LANG de_DE.UTF-8
ENV LANGUAGE de_DE.UTF-8
ENV LC_ALL de_DE.UTF-8
ENV POSTGRES_PASSWORD 'blabla'
ENV POSTGRES_HOST_AUTH_METHOD trust
RUN set -x && \
localedef -i de_DE -c -f UTF-8 -A /usr/share/locale/locale.alias de_DE.UTF-8
COPY test-data/. /docker-entrypoint-initdb.d/
CMD ["postgres"]
In the test-datafolder is a shell-script which executes the filling
#!/bin/sh
cd /docker-entrypoint-initdb.d
echo "read one.sql"
psql -v ON_ERROR_STOP=1 -U postgres < sql/one.sql
echo "read two.sql"
...
...
...
So the idea is to pre-fill the Postgres docker image with the schema and upload to the registry.

Answer 1

In theory you can rung postgres engine during docker build and execute whatever you need, here is not completely working example, i.e. postgres fails to start because there no configuration file.
if you spend more time on this i bet it should do the trick.
between your lines COPY test-data/. /docker-entrypoint-initdb.d/ and CMD ["postgres"] insert this
RUN adduser --disabled-password --gecos "" dbuser
RUN apt-get update
RUN apt-get install -y sudo
RUN echo "dbuser ALL=(root) NOPASSWD:ALL" > /etc/sudoers.d/dbuser && chmod 0440 /etc/sudoers.d/dbuser
USER dbuser:dbuser
RUN sudo chown -R dbuser:dbuser /docker-entrypoint-initdb.d
RUN sudo chown -R dbuser:dbuser /var/lib/postgresql/
RUN postgres
WORKDIR /docker-entrypoint-initdb.d
RUN psql -v ON_ERROR_STOP=1 -U postgres < sql/one.sql
at the moment that fails on RUN postgres - fails to find configuration on german, and i am not expert on postgres neither speak german so i wasn't able to solve right away.
also this part installs sudo and adds new dbuser into sudo group because postgress didn't want to start from root, so postgres runs from dbuser.
Hope this is going to help you moving into right direction :)