Why Docker for Laravel
Docker packages your application with its exact dependencies—PHP version, extensions, Node.js, database—into a portable container. Every developer runs the same environment. Staging mirrors production. Deployment becomes shipping an image, not running setup scripts. The "works on my machine" problem disappears permanently.
Docker Fundamentals
An image is a read-only template with your app and dependencies. A container is a running instance of an image. A Dockerfile defines how to build an image. docker-compose.yml orchestrates multiple containers—app, database, Redis, queue worker—into a single command. Understanding these four concepts is enough to get started.
Writing a Laravel Dockerfile
Start from php:8.4-fpm-alpine for a minimal base. Install required extensions: pdo_mysql, redis, gd, zip. Copy composer.json first, run composer install, then copy application code—this leverages Docker's layer caching so dependency installation only reruns when composer.json changes. This optimization alone can cut build times from minutes to seconds during development.
Local Development with docker-compose
Define services for the app with PHP-FPM and Nginx, MySQL, Redis, and a queue worker. Mount your source code as a volume for live reloading. Expose ports for browser access and database tools. Run docker-compose up -d and your entire stack starts in seconds. New team members clone the repo, run one command, and have a working environment.
Multi-Stage Builds for Production
Use multi-stage builds to keep production images small. Stage one installs Composer dependencies. Stage two builds frontend assets with Node.js. Stage three copies only compiled assets and the vendor directory into the final PHP image. The result: an image under 150MB instead of 800MB, with faster deployments and reduced attack surface.
Production Deployment
Push images to a container registry like Docker Hub, AWS ECR, or GitHub Container Registry. Deploy with Docker Swarm for simplicity or Kubernetes for scale. Use health checks, graceful shutdown handling, and rolling updates to achieve zero-downtime deployments. Tag images with Git commit hashes for traceability—you always know exactly which code is running in production.
Common Pitfalls
Do not run as root in production—create a non-root user in your Dockerfile. Do not store secrets in the image—use environment variables or secret managers. Do not ignore .dockerignore—exclude node_modules, .git, and storage/logs to speed up builds and keep images clean.
Conclusion
Docker eliminates environment inconsistencies, simplifies onboarding, and streamlines deployment. Start with docker-compose for local development, build optimized multi-stage images for production, and adopt orchestration tools as your infrastructure grows. The initial learning curve pays for itself within the first sprint.
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