Master Docker Middleware: Build PHP-FPM and MySQL Images Step‑by‑Step

Docker Practical Preparation

The preparation involves four steps: log in to OSChina Git, fork the docker‑training project, connect to the server via SSH, and clone your forked repository.

Build csphere/php-fpm:5.4 Image

# cd docker-training/php-fpm/
# ls 
Dockerfile          nginx_nginx.conf  supervisor_nginx.conf
nginx_default.conf  php_www.conf      supervisor_php-fpm.conf

Key configuration files:

nginx_nginx.conf – replaces the default nginx.conf

nginx_default.conf – replaces the default site config

php_www.conf – sets the PHP‑FPM user to nginx

supervisor_nginx.conf – starts nginx via Supervisor

supervisor_php-fpm.conf – starts php‑fpm via Supervisor

Dockerfile excerpt:

#
# MAINTAINER        Carson,C.J.Zeong <[email protected]>
# DOCKER-VERSION    1.6.2
#
FROM csphere/centos:7.1
ENV APP_DIR /app
RUN yum -y install nginx php-cli php-mysql php-pear php-ldap php-mbstring php-soap php-dom php-gd php-xmlrpc php-fpm php-mcrypt && yum clean all
ADD nginx_nginx.conf /etc/nginx/nginx.conf
ADD nginx_default.conf /etc/nginx/conf.d/default.conf
ADD php_www.conf /etc/php-fpm.d/www.conf
RUN sed -i 's/;cgi.fix_pathinfo=1/cgi.fix_pathinfo=0/' /etc/php.ini
RUN mkdir -p /app && echo "<?php phpinfo(); ?>" > ${APP_DIR}/info.php
EXPOSE 80 443
ADD supervisor_nginx.conf /etc/supervisor.conf.d/nginx.conf
ADD supervisor_php-fpm.conf /etc/supervisor.conf.d/php-fpm.conf
ONBUILD ADD . /app
ONBUILD RUN chown -R nginx:nginx /app

The ONBUILD instruction runs only when the image is used as a base for a child image.

Build and run the image:

docker build -t csphere/php-fpm:5.4 .

docker run -d -p 8080:80 --name website csphere/php-fpm:5.4

Access the container via http://your_ip:8080/info.php and enter the running container with docker exec -it website /bin/bash.

Build csphere/mysql:5.5 Image

#
# MAINTAINER        Carson,C.J.Zeong <[email protected]>
# DOCKER-VERSION    1.6.2
#
FROM csphere/centos:7.1
ENV DATA_DIR /var/lib/mysql
RUN yum install -y mariadb mariadb-server && yum clean all
ADD mysqld_charset.cnf /etc/my.cnf.d/
COPY scripts /scripts
RUN chmod +x /scripts/start
EXPOSE 3306
VOLUME ["/var/lib/mysql"]
ENTRYPOINT ["/scripts/start"]

The VOLUME directive maps host directories to the container, preserving data after container removal. The ENTRYPOINT runs the /scripts/start script on each container start.

Start script ( /scripts/start) initializes MariaDB on first run and ensures the MySQL socket is clean before launching mysqld_safe.

Docker Volume for Persistent Data

Define VOLUME["/data"] in Dockerfile.

Run container with

docker run -d -v <host_dir>:<container_dir> …

Case Study: Data Persistence

Run a MySQL container without a volume, create a database, stop and remove the container – data is lost.

Run a MySQL container with a volume, create a database, stop and remove the container – data remains in the host directory and can be re‑attached to a new container.

Commands used:

# docker run -d -p 3306:3306 --name dbserver csphere/mysql:5.5
# docker exec -it dbserver mysql -e "create database mydb;"
# docker stop dbserver && docker rm dbserver
# docker run -d -p 3306:3306 -v /var/lib/docker/vfs/dir/mydata:/var/lib/mysql csphere/mysql:5.5
# docker exec -it newdb mysql -e "show databases;"

Result: The mydb database persists across container recreation, demonstrating that Docker volumes protect data from container deletion.