Docker Services

Service Configuration Files

# docker-compose.override.yml (development)
services:
  php-fpm:
    build:
      context: ./docker/php
      dockerfile: Dockerfile.dev
    volumes:
      - ./src:/var/www/html
      - ./docker/php/xdebug.ini:/usr/local/etc/php/conf.d/xdebug.ini
    environment:
      - PHP_IDE_CONFIG=serverName=docker
      - XDEBUG_CONFIG=client_host=host.docker.internal

  nginx:
    volumes:
      - ./docker/nginx/default.dev.conf:/etc/nginx/conf.d/default.conf

PHP Service Config

php-fpm:
  build:
    context: ./docker/php
    dockerfile: Dockerfile
    args:
      PHP_VERSION: 8.2
      INSTALL_XDEBUG: true
  environment:
    - PHP_MEMORY_LIMIT=2G
    - PHP_MAX_EXECUTION_TIME=1800
    - PHP_UPLOAD_MAX_FILESIZE=100M
    - PHP_POST_MAX_SIZE=100M
  restart: unless-stopped
  healthcheck:
    test: ["CMD-SHELL", "php-fpm-healthcheck || exit 1"]
    interval: 30s
    timeout: 10s
    retries: 3

Environment Variable Management

# .env file
COMPOSE_PROJECT_NAME=magento2

# Database
MYSQL_ROOT_PASSWORD=root
MYSQL_DATABASE=magento
MYSQL_USER=magento
MYSQL_PASSWORD=magento

# Redis
REDIS_HOST=redis
REDIS_PORT=6379
REDIS_CACHE_DB=0
REDIS_SESSION_DB=1

# OpenSearch
OPENSEARCH_HOST=opensearch
OPENSEARCH_PORT=9200
OPENSEARCH_INDEX_PREFIX=magento2

# Application
APP_ENV=development
APP_DEBUG=1
APP_URL=http://localhost

Environment in docker-compose.yml

services:
  php-fpm:
    env_file:
      - .env
    environment:
      - MYSQL_HOST=${MYSQL_HOST:-mysql}
      - REDIS_HOST=${REDIS_HOST:-redis}
      - APP_ENV=${APP_ENV:-production}

  nginx:
    environment:
      - PHP_FPM_HOST=php-fpm
      - PHP_FPM_PORT=9000

Magento env.php

<?php
return [
    'http_cache_hosts' => [
        [
            'http_cache_host' => 'varnish',
            'port' => 80,
        ],
    ],
    'db' => [
        'connection' => [
            'default' => [
                'host' => getenv('MYSQL_HOST') ?: 'mysql',
                'dbname' => getenv('MYSQL_DATABASE') ?: 'magento',
                'username' => getenv('MYSQL_USER') ?: 'magento',
                'password' => getenv('MYSQL_PASSWORD') ?: 'magento',
            ],
        ],
    ],
    'cache' => [
        'frontend' => [
            'default' => [
                'backend' => 'Cm_Cache_Backend_Redis',
                'backend_options' => [
                    'server' => getenv('REDIS_HOST') ?: 'redis',
                    'port' => getenv('REDIS_PORT') ?: 6379,
                    'database' => getenv('REDIS_CACHE_DB') ?: 0,
                ],
            ],
        ],
    ],
    'session' => [
        'save' => 'redis',
        'redis' => [
            'host' => getenv('REDIS_HOST') ?: 'redis',
            'port' => getenv('REDIS_PORT') ?: 6379,
            'database' => getenv('REDIS_SESSION_DB') ?: 1,
        ],
    ],
];

Network Configuration

networks:
  magento-network:
    driver: bridge
    ipam:
      config:
        - subnet: 172.20.0.0/16

  frontend:
    driver: bridge

  backend:
    driver: bridge
    internal: true  # No external access

Service-to-Service Communication

services:
  nginx:
    networks:
      - frontend
      - backend
    depends_on:
      php-fpm:
        condition: service_healthy

  php-fpm:
    networks:
      - backend
    depends_on:
      mysql:
        condition: service_healthy
      redis:
        condition: service_healthy

  mysql:
    networks:
      - backend

DNS Resolution

# Docker provides DNS resolution between containers
# Use service name as hostname

# From php-fpm container:
mysql -h mysql -u magento -p
redis-cli -h redis

# From nginx container:
fastcgi_pass php-fpm:9000

Resource Limits

services:
  php-fpm:
    deploy:
      resources:
        limits:
          cpus: '2.0'
          memory: 2G
        reservations:
          cpus: '1.0'
          memory: 1G

  mysql:
    deploy:
      resources:
        limits:
          cpus: '2.0'
          memory: 2G
        reservations:
          cpus: '1.0'
          memory: 1G

Caching Strategies

services:
  redis:
    command: redis-server --appendonly yes --maxmemory 256mb --maxmemory-policy allkeys-lru

  opensearch:
    environment:
      - "OPENSEARCH_JAVA_OPTS=-Xms512m -Xmx512m"
      - "OPENSEARCH_INITIAL_ADMIN_PASSWORD=Admin@123"

Volume Performance

services:
  mysql:
    volumes:
      - mysql-data:/var/lib/mysql
      - type: tmpfs
        target: /tmp
        tmpfs:
          size: 100000000  # 100MB

Multi-Stage Builds

# Build stage
FROM php:8.2-fpm-alpine AS builder
RUN apk add --no-cache $PHPIZE_DEPS
RUN docker-php-ext-install pdo_mysql mbstring

# Production stage
FROM php:8.2-fpm-alpine
COPY --from=builder /usr/local/lib/php/extensions /usr/local/lib/php/extensions
COPY --from=builder /usr/local/etc/php/conf.d /usr/local/etc/php/conf.d

Health Check Scripts

#!/bin/bash
# docker/php/healthcheck.sh

# Check PHP-FPM
if ! php-fpm-healthcheck > /dev/null 2>&1; then
    echo "PHP-FPM unhealthy"
    exit 1
fi

# Check MySQL connection
if ! mysqladmin ping -h mysql -u root -p$MYSQL_ROOT_PASSWORD > /dev/null 2>&1; then
    echo "MySQL unhealthy"
    exit 1
fi

echo "All services healthy"
exit 0