How to Dockerize PHP Applications

At Dockerize It!, we specialize in making Docker accessible to PHP developers. In this article, we’ll cover the steps needed to Dockerize a PHP application and why doing so can improve your workflow, consistency, and deployment processes.

What is Docker and Why Should PHP Developers Use It?

Docker provides an isolated, consistent environment for developing and deploying applications. As a PHP developer, Docker can help you standardize your development environment across different machines, reduce "works on my machine" problems, and simplify deployment to production.

Dockerfile for PHP Applications

The core of Docker is the Dockerfile, which contains instructions to build your container image. Let’s take a look at a basic Dockerfile for a PHP application:


    FROM php:8.0-apache
    COPY . /var/www/html/
    RUN docker-php-ext-install mysqli
    EXPOSE 80
    CMD ["apache2-foreground"]

This Dockerfile builds a container with PHP 8.0 and Apache, copies your PHP code to the container, and installs the necessary PHP extensions.

Managing Multi-Container Applications with Docker Compose

For projects with multiple services (such as a PHP app with a database), docker-compose makes it easy to manage all the services together. Here’s an example of how to use Docker Compose for a PHP and MySQL app:


    version: '3'
    services:
      php:
        build: .
        ports:
          - "8080:80"
        depends_on:
          - db
      db:
        image: mysql:5.7
        environment:
          MYSQL_ROOT_PASSWORD: secret

Best Practices for Dockerizing PHP Applications

To get the most out of Docker for your PHP projects, here are a few best practices:

Use specific versions: Always specify exact versions of PHP, Apache, and MySQL to avoid unexpected changes.
Optimize image size: Use multi-stage builds to reduce image size by only including necessary components in the final image.
Persist data: Use Docker volumes for storing database and other persistent data to prevent data loss when containers are destroyed.

Conclusion

Docker is a powerful tool for PHP developers, enabling consistent environments and simplifying deployments. With Dockerfile and Docker Compose, you can easily build and manage both simple and complex PHP applications in containers.