Install WordPress on Raspberry Pi 4 with Docker (Ubuntu 22.04)

WordPress on Raspberry Pi 4 with Docker

WordPress is one of the most popular CMS platforms today. Thanks to Docker, it’s easy to host it even on a Raspberry Pi 4. This guide shows how to deploy WordPress on a Raspberry Pi 4 running Ubuntu 22.04 using Docker and Docker Compose.

Prerequisites

Before you begin, make sure you have the following:

Raspberry Pi 4 (4GB RAM or more recommended)
Ubuntu 22.04 (or a similar Linux distribution) installed
Docker and Docker Compose installed
Nginx Proxy Manager already set up (if you’re using a reverse proxy)
Stable internet connection
Basic command-line knowledge

Steps to Install WordPress on Raspberry Pi 4

1. Create Directories

sudo mkdir -p /opt/wordpress-obd-scan/html
sudo mkdir -p /opt/wordpress-obd-scan/db

2. Create `docker-compose.yml` File

Create a file docker-compose.yml and paste the following content:

mkdir ~/wordpress && cd ~/wordpress

version: '3.9'

services:
  wordpress:
    image: wordpress:latest
    container_name: wordpress-obd-scan
    restart: always
    environment:
      WORDPRESS_DB_HOST: wordpress_db
      WORDPRESS_DB_USER: wordpress_user
      WORDPRESS_DB_PASSWORD: strong_password
      WORDPRESS_DB_NAME: wordpress_db
    volumes:
      - /opt/wordpress-obd-scan/html:/var/www/html
    networks:
      - nginx-proxy-manager_npm_network
    expose:
      - "80"

  wordpress_db:
    image: mariadb:10.5
    container_name: wordpress-obd-scan-db
    restart: always
    environment:
      MYSQL_DATABASE: wordpress_db
      MYSQL_USER: wordpress_user
      MYSQL_PASSWORD: strong_password
      MYSQL_ROOT_PASSWORD: root_password
    volumes:
      - /opt/wordpress-obd-scan/db:/var/lib/mysql
    networks:
      - nginx-proxy-manager_npm_network

networks:
  nginx-proxy-manager_npm_network:
    external: true

Replace strong_password and root_password with secure values.

Note About Special Characters in YAML

When writing passwords or other values in your docker-compose.yml file, be careful with the characters you use—especially if you’re not using quotes.

Characters to Avoid Without Quotes:

These characters may cause parsing issues or unexpected behavior because they have special meanings in YAML:

! → used as a tag indicator

: → may be interpreted as a key-value separator

# → treated as a comment

{, }, [, ], ,, &, *, %, @ → may be interpreted as YAML syntax elements

Safe Characters (without quotes):

If you want to use unquoted passwords (not recommended for strong passwords), stick to the following characters:

Letters: a–z, A–Z

Numbers: 0–9

Safe symbols: ., -, _

Tip: For stronger passwords with special characters, always wrap the value in double quotes (").

Example:

MYSQL_ROOT_PASSWORD: “!SecurePass2025#”

Note About Access to the WordPress

Accessing WordPress via Port (Without Reverse Proxy)

If you don’t want to use a reverse proxy like Nginx Proxy Manager and prefer to access WordPress directly via a custom port (e.g., http://raspberrypi.local:8090), you can update the YAML configuration as follows:

Replace:

expose:
  - "80"

With:

ports:
  - "8090:80"

Explanation:

expose only makes the port available internally to other Docker containers on the same network.
ports publishes the container’s port to the host machine. In this case, port 80 inside the container becomes accessible from outside on port 8090.

???? So, if you open your browser and go to http://<raspberry-pi-ip>:8090, you’ll reach the WordPress site directly — no need for domain names or reverse proxy setup.

3. Start the Containers

With this command Docker will download the necessary images and start both WordPress and MariaDB containers:

sudo docker-compose up -d

4. Set Up a Reverse Proxy (Optional)

If you use Nginx Proxy Manager, create a new proxy host:

Forward hostname/IP: wordpress
Forward port: 80
Point your domain to the Raspberry Pi IP
Enable SSL via Let’s Encrypt (optional)

5. Define Domain in WordPress Configuration

Accessing the MariaDB Database Inside the WordPress Container

If you need to connect to the MariaDB database running in your wordpress-obd-scan-db container (e.g., to check or update WordPress site URLs), follow these steps:

Step 1: Open a Shell in the Database Container

Run this command from your host terminal:

docker exec -it wordpress-obd-scan-db sh

This gives you shell access inside the MariaDB container.

Step 2: Access the MariaDB

Inside the container, launch the MySQL client:

mysql -u wordpress -p

When prompted for a password, enter the one you defined under MYSQL_PASSWORD in your Docker Compose file.

(In your case, this was set to a value root_password — make sure to use your actual password.)

Step 3: Select the WordPress Database and Check URL Values

Once inside the MySQL client, select the database:

USE wordpress;

Then, check the current site URL and home URL values:

SELECT option_name, option_value FROM wp_options WHERE option_name IN ('siteurl', 'home');

Step 4 (Optional): Update the URL to Use HTTP or a Different Domain

If necessary, you can update the site URLs with:

UPDATE wp_options SET option_value = 'http://yourdomain.com' WHERE option_name IN ('siteurl', 'home');

???? This is useful if WordPress is redirecting to the wrong domain or protocol.

Step 5: Exit the MySQL Client and Container

From the MySQL prompt:

exit

From the container shell:

exit

Optional: Check If WordPress Domain Is Defined in `wp-config.php`

Sometimes WordPress domain settings (WP_HOME and WP_SITEURL) are defined directly in the configuration file. If these constants are set, they will override values in the database.

To check this:

Open the wp-config.php File

nano /opt/wordpress-obd-scan/html/wp-config.php

Look for These Lines:

define('WP_HOME', 'http://yourdomain.com');
define('WP_SITEURL', 'http://yourdomain.com');

What to Do:

If these lines are commented out with //, then WordPress uses the values from the database.

Configuration in Nginx Proxy Manager

Under Host you can configure the following:

Conclusion

You now have a fully working WordPress installation on your Raspberry Pi 4 using Docker. It’s ideal for testing, small projects, or learning web hosting from home.