Docker - extend the parent's ENTRYPOINT

Question

I've got a custom image based on the official postgres image and I want to extend the entrypoint of the parent image so that it would create new users and databases if they don't exist yet every time a container starts up. Is it possible? Like my image would execute all the commands from the standard entrypoint plus my own shell script.

I know about putting my own scripts into the /docker-entrypoint-initdb.d directory, but it seems that they get executed only when the volume is created the first time.

Answer 1

What you need to do is something like below

setup_user.sh

sleep 10
echo "execute commands to setup user"

setup.sh

sh setup_user.sh &
./docker-entrypoint.sh postgres

And your image should use the ENTRYPOINT as

ENTRYPOINT ["/setup.sh"]

You need to start your setup script in background and let the origin entryscript do its works to start the database