Is it possible to create my custom database while I create the image (docker image build --tag mydb:latest) ?
If I put my sql file to "/docker-entrypoint-initdb.d/" database will execute every time I start the container from that image.I don't want to run the database script every time I start because it is a huge database.

This is for automated testing. If I bind the volume, Database will become persistance. I don't want that either. Because my test cases will fail.

This is my Dockerfile

FROM postgres:10
COPY seed.sql         /tmp/
COPY init-db.sh       /tmp/
WORKDIR /tmp/
RUN ["chmod", "+x", "init-db.sh"]
RUN ./init-db.sh

This is my init-db.sh

#!/bin/bash
set -e
RETRIES=5
cd /usr/lib/postgresql/10/bin/
gosu postgres initdb
su postgres -c './pg_ctl start -D "/var/lib/postgresql/data"'
until psql -U postgres -d postgres -c "select 1" > /dev/null 2>&1 || [ $RETRIES -eq 0 ]; do
  echo "Waiting for postgres server, ${RETRIES}-- remaining attempts..."
  RETRIES=$((RETRIES--))
  sleep 1
done

psql -v ON_ERROR_STOP=1 -U postgres <<-EOSQL
    \i /tmp/seed.sql;
EOSQL

Usng above Dockerfile and init-db.sh I can see my database gets executed when I create the image.
But when I start the container with that image I don't see the database created by seed.sql.
So how can I create my own "postgres docker image" with my own database ?