We can use ENTRYPOINT
instead of CMD
within our Dockerfile's in order to setup a script that is always run (no matter what!) when a container is spun up from the image we make.
Entrypoint Script
First, we make a script to act as our ENTRYPOINT
:
#!/usr/bin/env bash
##
# Ensure /.composer exists and is writable
#
if [ ! -d /.composer ]; then
mkdir /.composer
fi
chmod -R ugo+rw /.composer
##
# Run a command or start supervisord
#
if [ $# -gt 0 ];then
# If we passed a command, run it
exec "$@"
else
# Otherwise start supervisord
/usr/bin/supervisord
fi
This script allows us to do some pre-processing whenever a container is spun up. It defaults to running supervisord
for us, but we also allow ourselves to run any command, just like we could before, by using the exec "$@"
line if we pass any commands/arguments to the container.
Dockerfile
Then we use that in the Dockerfile by adding it to the image and setting it as our ENTRYPOINT
script:
FROM ubuntu:18.04
LABEL maintainer="Chris Fidao"
ENV DEBIAN_FRONTEND=noninteractive
RUN apt-get update \
&& apt-get install -y gnupg tzdata \
&& echo "UTC" > /etc/timezone \
&& dpkg-reconfigure -f noninteractive tzdata
RUN apt-get update \
&& apt-get install -y curl zip unzip git supervisor sqlite3 \
nginx php7.2-fpm php7.2-cli \
php7.2-pgsql php7.2-sqlite3 php7.2-gd \
php7.2-curl php7.2-memcached \
php7.2-imap php7.2-mysql php7.2-mbstring \
php7.2-xml php7.2-zip php7.2-bcmath php7.2-soap \
php7.2-intl php7.2-readline php7.2-xdebug \
php-msgpack php-igbinary \
&& php -r "readfile('http://getcomposer.org/installer');" | php -- --install-dir=/usr/bin/ --filename=composer \
&& mkdir /run/php \
&& apt-get -y autoremove \
&& apt-get clean \
&& rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* \
&& echo "daemon off;" >> /etc/nginx/nginx.conf
RUN ln -sf /dev/stdout /var/log/nginx/access.log \
&& ln -sf /dev/stderr /var/log/nginx/error.log
ADD default /etc/nginx/sites-available/default
ADD supervisord.conf /etc/supervisor/conf.d/supervisord.conf
ADD php-fpm.conf /etc/php/7.2/fpm/php-fpm.conf
ADD start-container.sh /usr/bin/start-container
RUN chmod +x /usr/bin/start-container
ENTRYPOINT ["start-container"]
And of course, we need to rebuild the image:
docker build -t shippingdocker/app:latest \
-f docker/app/Dockerfile \
docker/app