How to create populated MySQL Docker Image on build time

Question

I would like to create a MySQL Docker image with data already populated.

I want to create 3 layers like this:

        |---------------------|--------         


        

Answer 1

MegaWubs's answer is great, except for this "sleep 30" that forces you to guess initdb's execution time. To avoid this, I put a small shell script to be executed after every others in /docker-entrypoint-initdb.d :

/docker-entrypoint-initdb.d/
  |- 01_my_data1.sql
  |- 02_my_data2.sql
  ...
  |- 99_last_processed_file.sh

With 99_last_processed_file.sh :

#!/usr/bin/env bash
touch /tmp/server_can_shutdown.txt

--

In parallel, in Dockerfile, I run another script in replacement of Mortenn's "sleep && killall" :

# Dockerfile
# ...
COPY wait_then_shutdown.sh /tmp/wait_then_shutdown.sh
RUN /entrypoint.sh mysqld & /tmp/wait_then_shutdown.sh  # <-- 
RUN rm /docker-entrypoint-initdb.d/*

With wait_then_shutdown.sh :

#!/usr/bin/env bash
while [ ! -f /tmp/server_can_shutdown.txt ] # <-- created by 99_last_processed_file.sh
do
  sleep 2
done
kill $(pidof mysqld)

--

And now, mysqld stops only when all other files are processed in /docker-entrypoint-initdb.d