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Declarative Docker Stack: Production-Grade Infrastructure as Code

Overview

A robust DevOps deployment must be fully declarative, version-controlled, and self-healing. By leveraging Docker Compose, custom PHP ini overlays, and automated reverse-proxy host resolution, the Peeksleek stack boots identically across local laptops, ephemeral playgrounds, and production cloud nodes.

1. Environment Configuration (.env)

Create .env in the project root to decouple credentials and operational ports from the Compose file:

# =============================================================================
# ENVIRONMENT VARIABLES: PEEKSLEEK DOCKER COMPOSE STACK
# =============================================================================
TZ=UTC

# MariaDB Credentials
DB_NAME=peekfenm_wp583
DB_USER=peekfenm_wp583
DB_PASSWORD=peeksleek_secure_db_pass_2026
DB_ROOT_PASSWORD=peeksleek_mariadb_root_pass_2026

# WordPress Configuration
WP_PORT=8080
WP_TABLE_PREFIX=wpw4_
PUBLIC_URL=http://localhost:8080

2. Docker Compose Specification (docker-compose.yml)

The compose file orchestrates all three services, establishes container dependencies via healthchecks, mounts configuration overlays, and declares isolated network namespaces:

services:
  # -------------------------------------------------------------------------
  # 1. DATABASE: MariaDB 10.11 (4GB Buffer Pool, Multi-Core Threading)
  # -------------------------------------------------------------------------
  db:
    image: mariadb:10.11
    container_name: peeksleek_db
    restart: unless-stopped
    command: [
      '--character-set-server=utf8mb4',
      '--collation-server=utf8mb4_unicode_ci',
      '--max_connections=300',
      '--innodb_buffer_pool_size=4G',
      '--innodb_log_file_size=512M',
      '--innodb_flush_log_at_trx_commit=2',
      '--tmp_table_size=256M',
      '--max_heap_table_size=256M',
      '--table_open_cache=4000'
    ]
    environment:
      MYSQL_ROOT_PASSWORD: ${DB_ROOT_PASSWORD}
      MYSQL_DATABASE: ${DB_NAME}
      MYSQL_USER: ${DB_USER}
      MYSQL_PASSWORD: ${DB_PASSWORD}
      TZ: ${TZ}
    volumes:
      - db_data:/var/lib/mysql
      - ./init-db:/docker-entrypoint-initdb.d:ro
    healthcheck:
      test: ["CMD", "healthcheck.sh", "--connect", "--innodb_initialized"]
      interval: 5s
      timeout: 5s
      retries: 25
      start_period: 15s
    networks:
      - peeksleek_internal
    logging:
      driver: "json-file"
      options:
        max-size: "20m"
        max-file: "3"

  # -------------------------------------------------------------------------
  # 2. IN-MEMORY CACHE: Redis 7 (1GB RAM Cache)
  # -------------------------------------------------------------------------
  redis:
    image: redis:7-alpine
    container_name: peeksleek_redis
    restart: unless-stopped
    command: ["redis-server", "--appendonly", "yes", "--maxmemory", "1024mb", "--maxmemory-policy", "allkeys-lru"]
    volumes:
      - redis_data:/data
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 5s
      timeout: 3s
      retries: 5
    networks:
      - peeksleek_internal
    logging:
      driver: "json-file"
      options:
        max-size: "10m"
        max-file: "3"

  # -------------------------------------------------------------------------
  # 3. APPLICATION: WordPress 6.8+ / PHP 8.2 Apache
  # -------------------------------------------------------------------------
  wordpress:
    image: wordpress:php8.2-apache
    container_name: peeksleek_app
    restart: unless-stopped
    depends_on:
      db:
        condition: service_healthy
      redis:
        condition: service_healthy
    ports:
      - "${WP_PORT}:80"
    environment:
      WORDPRESS_DB_HOST: db:3306
      WORDPRESS_DB_NAME: ${DB_NAME}
      WORDPRESS_DB_USER: ${DB_USER}
      WORDPRESS_DB_PASSWORD: ${DB_PASSWORD}
      WORDPRESS_TABLE_PREFIX: ${WP_TABLE_PREFIX}

      # -----------------------------------------------------------------------
      # REVERSE PROXY HOST & SSL DETECTION (iximiuz / Cloudflare / AWS)
      # Notice: PHP variables must be escaped with double-$$ for Compose!
      # -----------------------------------------------------------------------
      WORDPRESS_CONFIG_EXTRA: |
        $$_SERVER['HTTPS'] = 'on';

        // Check HTTP_X_FORWARDED_HOST first, fallback to HTTP_HOST:
        $$real_host = isset($$_SERVER['HTTP_X_FORWARDED_HOST']) ? $$_SERVER['HTTP_X_FORWARDED_HOST'] : (isset($$_SERVER['HTTP_HOST']) ? $$_SERVER['HTTP_HOST'] : 'localhost');

        define('WP_HOME', 'https://' . $$real_host);
        define('WP_SITEURL', 'https://' . $$real_host);

        define('WP_REDIS_HOST', 'redis');
        define('WP_REDIS_PORT', 6379);
        define('WP_MEMORY_LIMIT', '1024M');
        define('WP_MAX_MEMORY_LIMIT', '1024M');

    volumes:
      - ./custom-php/php-custom.ini:/usr/local/etc/php/conf.d/php-custom.ini:ro
      - ./wp-content:/var/www/html/wp-content
    networks:
      - peeksleek_internal
      - peeksleek_edge
    logging:
      driver: "json-file"
      options:
        max-size: "20m"
        max-file: "3"

volumes:
  db_data:
    driver: local
  redis_data:
    driver: local

networks:
  peeksleek_internal:
    driver: bridge
  peeksleek_edge:
    driver: bridge

3. Custom PHP Runtime Configuration (custom-php/php-custom.ini)

Create custom-php/php-custom.ini to override default PHP restrictions:

; -----------------------------------------------------------------------------
; Custom PHP-FPM / Apache Configuration for Peeksleek WooCommerce
; -----------------------------------------------------------------------------
memory_limit = 1024M
upload_max_filesize = 256M
post_max_size = 256M
max_execution_time = 300
max_input_vars = 5000

; Zend OPcache High-Performance Tuning
opcache.enable = 1
opcache.memory_consumption = 256
opcache.interned_strings_buffer = 32
opcache.max_accelerated_files = 20000
opcache.revalidate_freq = 2
opcache.fast_shutdown = 1
opcache.save_comments = 1

4. Key Architectural Patterns in this Compose File

Variable Escaping in Compose ($$)

In Docker Compose syntax, any token matching $VAR is interpreted as an environment variable to be evaluated on the host machine. Because PHP uses $, writing $_SERVER['HTTPS'] = 'on'; results in Docker replacing $_SERVER with an empty string, breaking PHP syntax.

Prefixing with $$ (e.g., $$_SERVER) instructs Compose to output a literal single $ into the generated /var/www/html/wp-config.php.

Dynamic Host Resolution (WP_HOME / WP_SITEURL)

Hardcoding a domain like https://peeksleek.com or http://localhost:8080 breaks preview environments behind dynamic ingress routers (such as iximiuz Labs or AWS ALBs). The injection snippet: 1. Checks for HTTP_X_FORWARDED_HOST passed by the reverse proxy. 2. Falls back to HTTP_HOST if directly accessed. 3. Automatically sets WP_HOME and WP_SITEURL to match the exact origin domain requested by the user's browser, preventing all cross-origin errors.