Containerization ensures consistency across local development, staging environments, and production Kubernetes clusters.

Optimizing Multi-Stage Dockerfile

By separating composer build steps from the final PHP-FPM runtime image, you can reduce image sizes from 1GB+ to under 120MB.

# Build stage
FROM composer:2 AS vendor
WORKDIR /app
COPY composer.json composer.lock ./
RUN composer install --no-dev --optimize-autoloader --no-scripts

# Production runtime
FROM php:8.2-fpm-alpine
WORKDIR /var/www/html
COPY . .
COPY --from=vendor /app/vendor ./vendor
RUN chown -R www-data:www-data storage bootstrap/cache