WordPress Deployment with NGINX, PHP-FPM and MariaDB using Docker Compose

WordPress

Today, nearly half of the top 1 million sites on the internet use the WordPress CMS (Content Management System). WordPress has a plethora of features and is very easy to use even for non-technical users which makes it a go-to CMS solution for many. However, setting up a website with WordPress in a VPS server or a Cloud server can be a pretty daunting task for both non-technical as well as technical users. We’ll learn how to do that in this article.

Docker

Docker is a software that can package your application, its dependencies, system tools, system libraries and settings in a single comprehensive virtual container. This combined package, which contains everything that’s needed to run your application, is called a Docker container image. This image is a standalone, executable software package which runs reliably on any server — Linux, Windows, macOS, public cloud or private cloud. Also, these images can be used to run the application as an isolated process in user space.

In this article, we’ll learn how to deploy WordPress using NGINX, PHP-FPM and MariaDB using Docker Compose in an Ubuntu machine. The below image illustrates the multi-container deployment that we intend to create.

Multi-Container Deployment of WordPress using Docker

Overview of the Installation Process

The steps in the deployment are summarized below.

1. Install Docker in the machine.
2. Create a docker-compose.yml file that enables us to create a multi-container deployment.
3. Add MariaDB configuration to docker-compose.yml.
4. Configure the host machine to handle database files.
5. Add WordPress configuration to docker-compose.yml.
6. Add a configuration section to nginx.conf file.
7. Add NGINX configuration to docker-compose.yml.
8. Create the containers and run the services.

1. Prepare the host machine

Install Docker

Please click the below link and follow the Docker installation instructions from the Docker website.

Get Docker Engine — Community for Ubuntu

Install Docker Compose

Please click the below link and follow the Docker Compose installation instructions from the Docker website.

Install Docker Compose

2. Add MariaDB configuration

Create a docker-compose.yml file and add the below configuration to the file. The configuration for MariaDB database is listed under the service name mysql.

version: '3'
services:
  mysql:
    image: mariadb
    volumes:
      - /data/mysql:/var/lib/mysql
    environment:
      MYSQL_ROOT_PASSWORD: mysql_root_pass
      MYSQL_DATABASE: db_name
      MYSQL_USER: user_name
      MYSQL_PASSWORD: user_pass
    restart: always

The below section mounts the host machine path /data/mysql in the container path /var/lib/mysql.

    volumes:
      - /data/mysql:/var/lib/mysql

This enables all our DB files to be stored in the host machine instead of the container. We need to prepare this directory for usage by our container.

In the MariaDB container, the directory /var/lib/mysql is owned by the user mysql. The uid of this user in the container is 999. It is not the same in Ubuntu — the host machine. The below commands delete any existing user with the user name mysql and creates a new user with uid 999.

$ sudo userdel mysql
$ sudo useradd -u 999 mysql

Now, set the owner of the directory/data/mysql in the host machine.

$ sudo mkdir -p /data/mysql
$ sudo chown -R mysql:mysql /data/mysql

3. Add WordPress Configuration

Add WordPress configuration to the docker-compose.yml file as a service named wordpress.

version: '3'
services:
  mysql:
    image: mariadb
    volumes:
      - /data/mysql:/var/lib/mysql
    environment:
      MYSQL_ROOT_PASSWORD: mysql_root_pass
      MYSQL_DATABASE: db_name
      MYSQL_USER: user_name
      MYSQL_PASSWORD: user_pass
    restart: always
  wordpress:
    image: wordpress:php7.3-fpm-alpine
    volumes:
      - /data/html:/var/www/html
    depends_on:
      - mysql
    environment:
      WORDPRESS_DB_HOST: mysql
      MYSQL_ROOT_PASSWORD: mysql_root_pass
      WORDPRESS_DB_NAME: db_name
      WORDPRESS_DB_USER: user_name
      WORDPRESS_DB_PASSWORD: user_pass
      WORDPRESS_TABLE_PREFIX: wp_
    links:
      - mysql
    restart: always

Make sure the WordPress environment variables MYSQL_ROOT_PASSWORD, WORDPRESS_DB_NAME, WORDPRESS_DB_USER, and WORDPRESS_DB_PASSWORD match exactly with the MariaDB environment variables MYSQL_ROOT_PASSWORD, MYSQL_DATABASE, MYSQL_USER, and MYSQL_PASSWORD respectively. In case of any mismatch, the WordPress application would not be able to connect to the database.

The below section states that the wordpress service is dependent on the mysql service. This implies that the services are started and stopped in the dependency order.

    depends_on:
      - mysql

The below section enables the wordpress service to communicate with the mysql service.

    links:
      - mysql

The below section mounts the host machine path /data/html in the container path /var/www/html.

    volumes:
      - /data/html:/var/www/html

This enables all our WordPress application files to be stored in the host machine instead of the container. We need to prepare this directory for usage by our container.

In the WordPress container, the directory /var/www/html is owned by the user www-data. The uid of this user in the container is 82. It is not the same in Ubuntu — the host machine. The below commands delete any existing user with the user name www-data and creates a new user with uid 82.

$ sudo userdel www-data
$ sudo useradd -u 82 www-data

Now, set the owner of the directory/data/html in the host machine.

$ sudo mkdir -p /data/html
$ sudo chown -R www-data:www-data /data/html

Add the below lines to the server section in nginx.conf to make sure all PHP requests are sent to the PHP-FPM service.

# pass the PHP scripts to FastCGI server listening on wordpress:9000
location ~ \.php$ {
  fastcgi_split_path_info ^(.+\.php)(/.+)$;
  fastcgi_pass wordpress:9000;
  fastcgi_index index.php;
  include fastcgi_params;
  fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
  fastcgi_param SCRIPT_NAME $fastcgi_script_name;
}

4. Add NGINX Configuration

Add NGINX configuration to the docker-composer.yml file as a service named nginx.

version: '3'
services:
  mysql:
    image: mariadb
    volumes:
      - /data/mysql:/var/lib/mysql
    environment:
      MYSQL_ROOT_PASSWORD: mysql_root_pass
      MYSQL_DATABASE: db_name
      MYSQL_USER: user_name
      MYSQL_PASSWORD: user_pass
    restart: always
  wordpress:
    image: wordpress:php7.3-fpm-alpine
    volumes:
      - /data/html:/var/www/html
    depends_on:
      - mysql
    environment:
      WORDPRESS_DB_HOST: mysql
      MYSQL_ROOT_PASSWORD: mysql_root_pass
      WORDPRESS_DB_NAME: db_name
      WORDPRESS_DB_USER: user_name
      WORDPRESS_DB_PASSWORD: user_pass
      WORDPRESS_TABLE_PREFIX: wp_
    links:
      - mysql
    restart: always
  nginx:
    image: nginx:alpine
    volumes:
      - nginx:/etc/nginx/conf.d
      - /data/html:/var/www/html
    ports:
      - 8080:80
    links:
      - wordpress

Make sure that the host path mentioned in the nginx configuration — /data/html — matches with the host path mentioned in the WordPress configuration.

The below section enables the wordpress service to communicate with the mysql service.

links:
      - wordpress

The below section maps the host machine port 8080 to the container port 80. Notice that no other container has any port exposed to the host machine. This enhances the security of our deployment.

ports:
      - 8080:80

We also need to provide a configuration file for the Nginx server. Create a directory named nginx and put the below contents in a file named nginx.conf in that directory.

server {
  listen 80;
  listen [::]:80;
  access_log off;
  root /var/www/html;
  index index.php;
  server_name example.com;
  server_tokens off;
  location / {
    # First attempt to serve request as file, then
    # as directory, then fall back to displaying a 404.
    try_files $uri $uri/ /index.php?$args;
  }
  # pass the PHP scripts to FastCGI server listening on wordpress:9000
  location ~ \.php$ {
    fastcgi_split_path_info ^(.+\.php)(/.+)$;
    fastcgi_pass wordpress:9000;
    fastcgi_index index.php;
    include fastcgi_params;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_param SCRIPT_NAME $fastcgi_script_name;
  }
}

Get Set Go!!!

Now create the containers and run the services with the below command.

$ sudo docker-compose up -d

Once the installation is over, open up the URL http://localhost:8080 in your browser. This should show the WordPress initial setup page.

Choice of the path in Volumes

Notice that the database files are stored in the directory /data/mysql in the host machine and the wordpress files are stored in the directory /data/wordpress in the host machine. In our installation, these are the only directories that contain user data. And both these directories are in the host machine. Hence, you can easily backup all user data by simply creating a tarball of the /data directory as given below:

$ sudo tar -jcvf data.tar.bz2 /data

How to Upgrade?

Another question is how to upgrade to the latest version of nginx or wordpress docker images in our deployment. Since all user data is outside the containers, we can easily delete the containers and re-create them to upgrade our installation.

$ sudo docker-compose down --rmi all
$ sudo docker-compose up -d