How to execute script during image build in Docker

I have the following at the end of my `Dockerfile`: ``` ENTRYPOINT bash -C '/usr/local/bin/setup_php_settings';'bash' ``` If I am not wrong that `/usr/local/bin/setup_php_settings` will be executed each time the container is started. If so then I have a few installation stuff (like this ZRay for example) inside that script that I would like to move to another script that would be executed just once on image build process let's say. The content of the `setup_php_settings` (whithout the ZRay part) is the following: ``` #!/bin/bash -x set -e PHP_ERROR_REPORTING=${PHP_ERROR_REPORTING:-"E_ALL & ~E_DEPRECATED & ~E_NOTICE"} sed -ri 's/^display_errors\s*=\s*Off/display_errors = On/g' /etc/php5/apache2/php.ini sed -ri 's/^display_errors\s*=\s*Off/display_errors = On/g' /etc/php5/cli/php.ini sed -ri "s/^error_reporting\s*=.*$//g" /etc/php5/apache2/php.ini sed -ri "s/^error_reporting\s*=.*$//g" /etc/php5/cli/php.ini echo "error_reporting = $PHP_ERROR_REPORTING" >> /etc/php5/apache2/php.ini echo "error_reporting = $PHP_ERROR_REPORTING" >> /etc/php5/cli/php.ini mkdir -p /data/tmp/php/uploads mkdir -p /data/tmp/php/sessions mkdir -p /data/tmp/php/xdebug chown -R www-data:www-data /data/tmp/php* ln -sf /etc/php5/mods-available/zz-php.ini /etc/php5/apache2/conf.d/zz-php.ini ln -sf /etc/php5/mods-available/zz-php-directories.ini /etc/php5/apache2/conf.d/zz-php-directories.ini ln -sf /usr/share/php/libzend-framework-php/Zend/ /usr/share/php/Zend a2enmod rewrite php5enmod mcrypt # Apache gets grumpy about PID pre-existing files : "${APACHE_PID_FILE:=${APACHE_RUN_DIR:=/var/run/apache2}/apache2.pid}" rm -f "$APACHE_PID_FILE" source /etc/apache2/envvars && exec /usr/sbin/apache2 -DFOREGROUND "$@" ``` The question is, how do I execute such new script during image build? Using `CMD`? Any other workaround?