WordPress on Alpine Linux

WordPress setup for Docker, build on Alpine Linux. The image is only +/- 70MB large.

Repository: https://github.com/erseco/alpine-wordpress

• Built on the lightweight image https://github.com/erseco/alpine-php-webserver
• Very small Docker image size (+/-70MB)
• Uses PHP-FPM for better performance, lower cpu usage & memory footprint
• Multi-arch support: 386, amd64, arm/v6, arm/v7, arm64, ppc64le, s390x
• Optimized for 1000 concurrent users
• Optimized to only use resources when there's traffic (by using PHP-FPM's ondemand PM)
• Use of runit instead of supervisord to reduce memory footprint
• docker-compose sample with MariaDB
• Configuration via ENV variables
• Easily upgradable to new WordPress versions
• Includes WP-CLI for command-line management and automation of WordPress tasks, enhancing site management and deployment capabilities.
• The servers Nginx, PHP-FPM run under a non-privileged user (nobody) to make it more secure
• The logs of all the services are redirected to the output of the Docker container (visible with docker logs -f <container name>)
• Follows the KISS principle (Keep It Simple, Stupid) to make it easy to understand and adjust the image to your needs

Usage

Start the Docker containers:

docker-compose up

Login on the system using the provided credentials (ENV vars)

Running Commands as Root

In certain situations, you might need to run commands as root within your WordPress container, for example, to install additional packages. You can do this using the docker-compose exec command with the --user root option. Here's how:

docker-compose exec --user root wordpress sh

WordPress Plugin Development Environment Setup

Below is a docker-compose.yml example specifically designed for WordPress plugin development. This configuration provides a comprehensive setup for developing, testing, and deploying WordPress plugins efficiently.

services:
  mariadb:
    image: mariadb:latest
    restart: unless-stopped
    environment:
      - MYSQL_ROOT_PASSWORD=wordpress
      - MYSQL_DATABASE=wordpress
      - MYSQL_USER=wordpress
      - MYSQL_PASSWORD=wordpress
    volumes:
      - mariadb:/var/lib/mysql

  wordpress:
    image: erseco/alpine-wordpress:latest
    restart: unless-stopped
    depends_on:
      - mariadb
    ports:
      - 8080:8080      
    environment:
      WP_LANGUAGE: es_ES
      WP_ADMIN_USERNAME: admin
      WP_ADMIN_PASSWORD: PLEASE_CHANGEME
      WP_DEBUG: true
      WP_PLUGINS: user-access-manager
      WP_SITE_URL: http://localhost:8080
      POST_CONFIGURE_COMMANDS: |
        echo "Creating user for testing"
        if ! wp user get test1 --field=ID --quiet; then
          wp user create test1 [email protected] --role=subscriber --user_pass=test1
        fi
        echo "Activating plugin"
        wp plugin activate my-plugin
    volumes:
      - wordpress:/var/www/html
      - ./my-plugin:/var/www/html/wp-content/plugins/my-plugin

volumes:
  mariadb: null
  wordpress: null

• MariaDB service: Configures a MariaDB database with WordPress-specific settings, ensuring data persistence through Docker volumes.
• WordPress service:
  • Uses erseco/alpine-wordpress:latest, tailored for WordPress development.
  • Sets up WordPress with Spanish language, admin credentials, and enables debugging.
  • Pre-installs and activates specified plugins, including a custom plugin located in ./my-plugin.
  • Executes custom commands after configuration, like creating a test user and activating the developed plugin.
  • Maps port 8080, allowing local access to the WordPress site.
  • Depends on the mariadb service for database connectivity.

How to Use

1. Save the provided docker-compose.yml in your project directory.
2. Place your plugin code inside a directory named my-plugin in the same location.
3. Execute docker-compose up -d in your terminal, within the project directory.
4. Access your WordPress site at http://localhost:8080 to test and develop your plugin in a real-world environment.

This setup streamlines the plugin development process, from coding and testing to deployment, within a controlled and consistent environment.

Configuration

Define the ENV variables in docker-compose.yml file

Variable Name	Default	Description
WP_LANGUAGE	en_US	WordPress site language
DB_HOST	mariadb	Database host
DB_PORT	3306	MySQL default port
DB_NAME	wordpress	Database name
DB_USER	wordpress	Database user
DB_PASSWORD	wordpress	Database password
DB_PREFIX	wp_	Database prefix for WordPress tables
WP_ADMIN_EMAIL	[email protected]	WordPress admin email
WP_ADMIN_USERNAME	admin	WordPress admin username
WP_ADMIN_PASSWORD	PLEASE_CHANGEME	WordPress admin password
WP_DEBUG	false	Enable/disable WordPress debugging
WP_CLI_CACHE_DIR	/tmp/wp-cli/cache/	WP-CLI cache directory path
WP_THEME		Active WordPress theme
WP_PLUGINS		Comma-separated list of WordPress plugins
WP_SITE_TITLE	WordPress Site	Title of the WordPress site
WP_SITE_DESCRIPTION	Just another WordPress site	Description of the WordPress site
WP_SITE_URL	http://localhost:8080	WordPress site URL
client_max_body_size	50M	Maximum allowed size of client request bodies
post_max_size	50M	Maximum size of POST data that PHP will accept
upload_max_filesize	50M	Maximum size of an uploaded file
max_input_vars	5000	Maximum number of input variables for PHP
zlib_output_compression	Off	Disable zlib compresion for PHP
PRE_CONFIGURE_COMMANDS		Commands to run before starting the configuration
POST_CONFIGURE_COMMANDS		Commands to run after finished the configuration