I am using docker to run a develop environment for several wordpress themes / plugins. However, I can't figure out how to enable my themes automatically on container creation. Normally I would just use wp-cli for this. I have created a custom image that extends the official wordpress image, but I can't figure out how to make the wp-cli commands run after the /var/www/html folder get's setup (I think this is created by the wordpress image entrypoint script). If I put the commands in a "RUN" command in the dockerfile, the commands just fail since the /var/www/html directory is empty. However, if I connect to the container once it is setup, the directory is populated, and wp-cli works just fine. How can I run a command after the entrypoint.sh from the parent image is run?
Here is the content of my dockerfile (which does not work):
FROM wordpress
MAINTAINER Me!
COPY docker-install/wp-cli.phar /usr/local/bin/wp
WORKDIR /var/www/html
RUN chmod u+x /usr/local/bin/wp
RUN /usr/local/bin/wp core install --title="Test WP Site" --admin_user=admin --admin_password=something --admin_email=my@cool.email --url=localhost:8080 --allow-root
RUN /usr/local/bin/wp theme activate mytheme --allow-root