Master WordPress on Docker: Setup and configuration

Containerization has revolutionized how modern web applications are developed, deployed, and maintained – and WordPress is no exception. In fact, a WordPress Docker setup has become the go-to solution for those seeking a more efficient, scalable, and consistent way to manage their websites. 

Gone are the days of “it works on my machine” headaches –  a common and frustrating scenario in software development where an application functions perfectly on a developer’s local environment but fails to work correctly when deployed to another environment. With Docker, you can encapsulate all the dependencies, configurations, and code for your WordPress project into lightweight containers that run the same everywhere – be it on your local development laptop or in a production cloud environment.

This guide will walk you through the essential steps and best practices for containerizing WordPress, ensuring top-notch performance, airtight security, and effortless scalability. You’ll understand how to set up WordPress with Docker and be equipped with advanced techniques for optimizing and future-proofing your entire stack!

Why a WordPress Docker setup matters

While WordPress has long been recognized for its ease of use and robust content management capabilities, it can still suffer from configuration inconsistencies, lingering “it works on my machine” issues, and performance bottlenecks in certain environments. That’s why you need a Dockerized approach.

Consistency across all environments

Traditional setups often rely on manual configuration or full virtual machines, which can introduce unexpected variances. A WordPress Docker setup allows you to package all dependencies – like PHP, Apache/Nginx, and MySQL – within lightweight, standalone containers. This guarantees that every environment, from development to staging to production, shares the same configuration. No more wasting time troubleshooting environment-specific quirks or library mismatches.

Effortless portability and scalability

Docker’s container-based model excels at portability. You can replicate or move your exact WordPress environment from a local workstation to a cloud provider (Liquid Web, AWS, Google Cloud, Azure) with minimal friction. Even better, scaling up becomes a breeze: spinning up additional containers in a cluster to handle surges in traffic or high-concurrency workloads can be done almost instantly.

Resource efficiency

One of Docker’s key advantages over traditional virtual machines is its lightweight nature. Containers share the host operating system kernel, meaning they can start up faster, take up fewer resources, and are simpler to maintain. This translates into:

Enhanced security and isolation

Docker’s isolation capabilities help confine processes within containers, reducing potential attack surfaces. Even if one container is compromised, the issue is far less likely to spread to the rest of your server. By following container security best practices – like scanning images for vulnerabilities and consistently applying patches – you create a robust defense for your WordPress site.

Simplified collaboration and onboarding

For teams of developers, a standardized Docker-based workflow ensures everyone is working with the same environment from day one. Onboarding new team members becomes a matter of cloning a repository and running a single command. This eliminates setup woes and fosters a more efficient, collaborative atmosphere.

Prerequisites and local development setup

1. Docker and Docker Compose installation

When it comes to containerizing WordPress, you’ll need Docker Engine (on Linux) or Docker Desktop (on Windows and macOS) to manage containers.

Docker Engine, typically installed via a package manager like apt on Ubuntu or dnf on Fedora, provides command-line control for those who prefer direct oversight of the Docker daemon. If you’re on macOS or Windows, Docker Desktop bundles Docker Engine, the Docker CLI, and a lightweight virtual machine into one package, offering a streamlined GUI and easy configuration of resource usage such as CPU and RAM.

Regardless of your choice, make sure your Docker version is up to date. Run docker –version to verify this, and test with docker run hello-world to ensure your setup is fully functional. 

You’ll also need Docker Compose, a tool that orchestrates multi-container applications. In newer releases, Docker Compose may already be included under the docker compose command. Otherwise, you’ll need to install it separately. If you plan to scale to multiple nodes or use advanced orchestration, keep in mind that Docker Compose also integrates with Docker Swarm, allowing you to go beyond single-host deployments.

2. Structuring your project

A clear project structure is essential for maintainability and collaboration. Here’s what you need to do:

1. Create a dedicated folder to hold all Docker-related files and name it something like wordpress-docker-setup/

Within this folder, place your docker-compose.yml file (define and manage multi-container Docker applications), as well as any custom Dockerfiles, shell scripts, or documentation. 

2. Track everything in a version control system

Version control is very important. Git, for example, lets you collaborate with teammates, revert troublesome changes, and keep historical snapshots. Many teams will maintain separate branches (dev, staging, production) to reflect distinct Docker configurations for different environments.

3. Set up secret management

To keep sensitive data out of your Compose files, use a .env file to specify database credentials, API keys, or other secrets your containers need to function. Reference these environment variables within your Compose configuration, ensuring the actual secret values remain hidden from your repository. At the very least, add the .env file to your .gitignore so you don’t accidentally commit private information. 

For production environments, tools such as Docker Secrets (in Swarm or Kubernetes) or external secrets managers (like HashiCorp Vault) provide a more secure means of storing sensitive credentials.

3. Basic command-line skills

While graphical interfaces like Docker Desktop and Portainer can help visualize containers, acquiring a solid command-line foundation is invaluable for debugging and automation:

docker run -d <image_name>

docker stop <container_name>

docker compose logs -f

docker system prune -a

Building a basic WordPress and MySQL Docker stack

A reliable WordPress Docker setup typically involves two core containers: one running WordPress itself and another providing the MySQL database. Docker Compose orchestrates these containers so they communicate seamlessly while remaining isolated from other processes on your system. Also, by defining everything in a single YAML file, you gain a clear, reproducible blueprint for spinning up and tearing down your entire environment on demand.

1. Laying the foundation with docker-compose.yml

The docker-compose.yml file acts as the blueprint for your WordPress environment. Within it, you specify the images you want to run, the ports you need to expose, and how different containers should interact. 

In a simple WordPress setup, one container runs the official WordPress image, while another runs a MySQL image to store your site’s data. These containers are linked internally by a virtual Docker network, but you only expose the WordPress container’s port (port 80) to the host for public access.

Below is an example of a docker-compose.yml that sets up WordPress and MySQL. You can adapt the version numbers, credentials, or volume names to match your needs. In this example, the WordPress container is bound to port 8080 on the host, allowing you to view the site in a web browser by going to http://localhost:8080:

services:
  db:
    image: mysql:8.4
    container_name: wordpress_db
    environment:
      MYSQL_DATABASE: exampledb
      MYSQL_USER: exampleuser
      MYSQL_PASSWORD: examplepass
      MYSQL_ROOT_PASSWORD: rootpassword
    volumes:
      - db_data:/var/lib/mysql

This file references two containers: wordpress_app and wordpress_db. The WordPress container sets environment variables that point to the db service for all database interactions, while the MySQL container initializes a database named exampledb along with a specific user and password. The depends_on parameter ensures that the database container starts before WordPress attempts to connect.

2. Managing data with volumes

Persistence of data is crucial, especially for production sites. By default, containers are ephemeral, meaning that if a container is removed, data stored inside it disappears. To remedy this, Docker uses volumes, which are directories on the host (or in a dedicated volume driver) mapped to specific paths inside the container. 

In the sample Compose file above, two volumes are defined:

Mounting wp-content ensures you can easily edit themes or plugins from your local filesystem or directly push them to source control. This also means any media files uploaded through WordPress remain persistent across container restarts. 

The db_data volume preserves the database files so that if the MySQL container restarts, your data remains intact. For production deployments, you might use more sophisticated storage solutions – such as NFS shares, cloud block storage, or dedicated database services – to ensure high availability and robust backup options.

3. Bringing up your containers

Once your docker-compose.yml is ready, navigate to the project directory and run the following command to start all defined containers in detached mode:

docker compose up -d

Docker retrieves any missing images from Docker Hub, configures networks, and then launches each service in the correct order.

You can confirm everything is running by checking your active containers with:

docker compose ps. 

Sometimes, a container may fail due to incorrect environment variables, port conflicts, or permission issues on mounted volumes. Logs are your primary diagnostic tool for identifying these root causes quickly. If that happens, examine logs with:

docker compose logs -f

4. Finalizing your WordPress installation

After your containers are running, visit http://localhost:8080 in a web browser to display the WordPress setup wizard. Here, you can enter a site title, set up admin credentials, and confirm the language settings. 

WordPress will connect to the MySQL container using the credentials you specified in the Compose file. If the wizard displays a database error, verifying the environment variables in docker-compose.yml or checking whether the MySQL container has fully initialized can help. On success, the standard WordPress dashboard appears as it would on any traditional installation.

Configuring WordPress and addressing common pitfalls

After launching a basic WordPress and MySQL stack with Docker, you’ll want to fine-tune your setup to ensure it runs smoothly across different environments. 

Initial WordPress setup and database configuration

When you first access your WordPress site at http://localhost:8080 (or whatever port you’ve mapped), WordPress runs its setup wizard and prompts you to create an admin account. During this process, it communicates with the MySQL container using the credentials you defined in docker-compose.yml. 

If you encounter a database connection error at this point, double-check the environment variables for the WordPress container (WORDPRESS_DB_HOST, WORDPRESS_DB_USER, WORDPRESS_DB_PASSWORD, WORDPRESS_DB_NAME) and make sure they match the user and database that MySQL initialized. Also, confirm that the MySQL container has fully started by checking its logs. Sometimes, the WordPress container attempts to connect before MySQL finishes creating the initial database, causing a temporary error.

File permissions in a Dockerized environment

File permission issues can be especially confusing in Dockerized WordPress setups, particularly if you’re coming from a traditional shared hosting environment. On many Linux-based servers, Apache or NGINX runs under a user named www-data. If you mount your local filesystem into the container, that user must have adequate read and write privileges on the wp-content directory (and any directories within it, such as uploads or plugins). If your host system user and the container’s www-data user have mismatched IDs, you may see “permission denied” errors when WordPress tries to write files.

To resolve this, ensure that the container has ownership of the relevant folders. For example, on Linux, you might run sudo chown -R www-data:www-data wp-content in the project directory. 

If you’re using Docker Desktop on Windows or macOS, the file-sharing abstractions typically handle these permissions automatically, but edge cases can still occur. Checking the container’s logs and using docker compose exec wordpress_app ls -l /var/www/html/wp-content can confirm whether the user IDs and permissions are set correctly.

Security hardening and best practices

Security considerations in a Dockerized WordPress stack begin with container isolation. Since each container runs in its own sandbox, the database container is not publicly exposed unless you explicitly map its port to the host. WordPress connects to MySQL through Docker’s internal network, which reduces the attack surface considerably. That said, there are additional steps you can take to fortify your site.

One essential practice is keeping your base images updated. Docker allows you to quickly pull new versions of WordPress or MySQL that contain important security patches. Make a habit of running docker compose pull before a deployment to ensure you’re on the latest stable release. 

Likewise, applying updates within WordPress itself is still necessary, as containers don’t eliminate vulnerabilities in themes or plugins. Scanning your Docker images for known CVEs using tools like Trivy or Snyk can help you detect security gaps early.

You can also limit what ports are exposed to the outside world. In a production environment, only the WordPress container should expose port 80 (or 443 for HTTPS). The MySQL container should remain accessible solely on Docker’s internal network, preventing any direct public access to the database. Enforcing strong passwords and changing your WordPress wp-admin login URL – using a plugin or custom configuration – adds additional security layers against brute force attacks.

Scale your containerized WordPress with managed hosting

As you’ve seen throughout this post, a WordPress Docker setup transforms how you build, deploy, and maintain your WordPress sites. It gives you consistent environments, portability, resource efficiency, and security isolation.

However, containerization is not the only path to a high-performance WordPress experience. For many businesses – especially those focused on growth, uptime, and top-tier support – Liquid Web’s managed WordPress hosting can be a game-changer.

Rather than juggling Docker containers, patches, and OS updates yourself, you can rely on Liquid Web to optimize your hosting environment. Our infrastructure handles automatic updates, offers industry-leading security features, and includes expert-level support, all tailored specifically for WordPress. You get the benefits of a fully managed solution without the headaches of manual server maintenance or scaling complexities.

If you’re looking to streamline your WordPress environment, keep your site running at peak performance, and ensure you have a dedicated support team ready to tackle any issue, Liquid Web is ready to help. From DevOps-friendly solutions to fully managed WordPress hosting, Liquid Web’s services give you the freedom to focus on creating great content and growing your business.

Explore Liquid Web’s managed WordPress hosting today and enjoy the reliability, speed, and scalability your site needs and deserves!