Blog Fresa - Wordpress docker

Notes on deploying a single site WordPress FPM Edition instance as a docker deployment orchestrated by Docker Compose.

• Use the FPM version of WordPress (v5-fpm)
• Use MySQL as the database (v8)
• Use Nginx as the web server (v1)
• Include self-signed SSL certificate (Let's Encrypt localhost format)

Table of contents

• Overview
  • Host requirements
• Configuration
• Deploy
• Teardown
• References
• Notes

Overview

WordPress is a free and open source blogging tool and a content management system (CMS) based on PHP and MySQL, which runs on a web hosting service. Features include a plugin architecture and a template system.

This variant contains PHP-FPM, which is a FastCGI implementation for PHP.

• See the PHP-FPM website for more information about PHP-FPM.
• In order to use this image variant, some kind of reverse proxy (such as NGINX, Apache, or other tool which speaks the FastCGI protocol) will be required.

Host requirements

Both Docker and Docker Compose are required on the host to run this code

• Install Docker Engine: https://docs.docker.com/engine/install/
• Install Docker Compose: https://docs.docker.com/compose/install/

Configuration

Copy the env.template file as .env and populate according to your environment

# docker-compose environment file
#
# When you set the same environment variable in multiple files,
# here’s the priority used by Compose to choose which value to use:
#
#  1. Compose file
#  2. Shell environment variables
#  3. Environment file
#  4. Dockerfile
#  5. Variable is not defined

# Wordpress Settings
export WORDPRESS_LOCAL_HOME=./wordpress
export WORDPRESS_UPLOADS_CONFIG=./config/uploads.ini
export WORDPRESS_DB_HOST=database:3306
export WORDPRESS_DB_NAME=wordpress
export WORDPRESS_DB_USER=wordpress
export WORDPRESS_DB_PASSWORD=password123!

# Nginx Settings
export NGINX_CONF=./nginx/default.conf
export NGINX_SSL_CERTS=./ssl
export NGINX_LOGS=./logs/nginx

# User Settings
# TBD

Modify nginx/default.conf and replace $host and 443 with your Domain Name and exposed HTTPS Port throughout the file

# default.conf
# redirect to HTTPS
server {
    listen 80;
    listen [::]:80;
    server_name $host;
    location / {
        # update port as needed for host mapped https
        rewrite ^ https://$host:443$request_uri? permanent;
    }
}

server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    server_name $host;
    index index.php index.html index.htm;
    root /var/www/html;
    server_tokens off;
    client_max_body_size 75M;

    # update ssl files as required by your deployment
    ssl_certificate /etc/ssl/fullchain.pem;
    ssl_certificate_key /etc/ssl/privkey.pem;

    # logging
    access_log /var/log/nginx/wordpress.access.log;
    error_log /var/log/nginx/wordpress.error.log;

    # some security headers ( optional )
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-XSS-Protection "1; mode=block" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header Referrer-Policy "no-referrer-when-downgrade" always;
    add_header Content-Security-Policy "default-src * data: 'unsafe-eval' 'unsafe-inline'" always;

    location / {
        try_files $uri $uri/ /index.php$is_args$args;
    }

    location ~ \.php$ {
        try_files $uri = 404;
        fastcgi_split_path_info ^(.+\.php)(/.+)$;
        fastcgi_pass wordpress:9000;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PATH_INFO $fastcgi_path_info;
    }

    location ~ /\.ht {
        deny all;
    }

    location = /favicon.ico {
        log_not_found off; access_log off;
    }

    location = /favicon.svg {
        log_not_found off; access_log off;
    }

    location = /robots.txt {
        log_not_found off; access_log off; allow all;
    }

    location ~* \.(css|gif|ico|jpeg|jpg|js|png)$ {
        expires max;
        log_not_found off;
    }
}

Modify the config/uploads.ini file if the preset values are not to your liking (defaults shown below)

file_uploads = On
memory_limit = 256M
upload_max_filesize = 75M
post_max_size = 75M
max_execution_time = 600

Included uploads.ini file allows for Maximum upload file size: 75 MB

Deploy

Once configured the containers can be brought up using Docker Compose

1. Set the environment variables and build the images

   source .env
   docker-compose pull

2. Bring up the WordPress and Nginx containers

   docker-compose up -d 

   After a few moments the containers should be observed as running

   $ docker-compose ps
   NAME                COMMAND                  SERVICE             STATUS              PORTS
   wp-nginx            "/docker-entrypoint.…"   nginx               running             0.0.0.0:80->80/tcp, 0.0.0.0:443->443/tcp
   wp-wordpress        "docker-entrypoint.s…"   wordpress           running             9000/tcp

Teardown

For a complete teardown all containers must be stopped and removed along with the volumes and network that were created for the application containers

Commands

docker-compose stop
docker-compose rm -fv
docker-network rm wp-wordpress
# removal calls may require sudo rights depending on file permissions
rm -rf ./wordpress
rm -rf ./logs

Expected output

$ docker-compose stop
[+] Running 3/3
 ⠿ Container wp-nginx      Stopped                                                                                                     0.3s
 ⠿ Container wp-wordpress  Stopped                                                                                                     0.2s
$ docker-compose rm -fv
Going to remove wp-nginx, wp-wordpress
[+] Running 3/0
 ⠿ Container wp-nginx      Removed                                                                                                     0.0s
$ docker network rm wp-wordpress
wp-wordpress
$ rm -rf ./wordpress
$ rm -rf ./logs

References

• WordPress Docker images: https://hub.docker.com/_/wordpress/
• Nginx Docker images: https://hub.docker.com/_/nginx/

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Notes

General information regarding standard Docker deployment of WordPress for reference purposes

Let's Encrypt SSL Certificate

Use: https://github.com/RENCI-NRIG/ez-letsencrypt - A shell script to obtain and renew Let's Encrypt certificates using Certbot's --webroot method of certificate issuance.

Error establishing database connection

This can happen when the wordpress container attempts to reach the database prior to it being ready for a connection.

This will sometimes resolve itself once the database fully spins up, but generally it's advised to start the database first and ensure it's created all of its user and wordpress tables and then start the WordPress service.

Port Mapping

If you wish to expose the ports to the host, you'd need to alter the stanzas for each in the docker-compose.yml file.

For the wordpress stanza, add

    ports:
      - "9000:9000"