# High-Availability configuration for eXeLearning with Redis
# Use with: docker compose -f docker-compose.redis.yml up -d
#
# This configuration provides:
# - Two eXeLearning instances for high availability
# - PostgreSQL database (shared)
# - Redis for Yjs WebSocket synchronization across instances
# - Nginx load balancer with WebSocket support
#
# Architecture:
#   nginx (port 80) -> exelearning-1 (8080) + exelearning-2 (8080)
#                  \-> postgres (5432)
#                  \-> redis (6379)

services:
  # Load Balancer
  nginx:
    image: nginx:alpine
    ports:
      - "${LB_PORT:-80}:80"
    volumes:
      - ./nginx-ha.conf:/etc/nginx/nginx.conf:ro
    # Must be at least nginx-ha.conf's worker_rlimit_nofile, or nginx can't
    # actually use the higher limit it asks for. Validated by issue #2255's
    # benchmark — see nginx-ha.conf's own comment for the measured numbers.
    ulimits:
      nofile:
        soft: 200000
        hard: 200000
    depends_on:
      exelearning-1:
        condition: service_healthy
      exelearning-2:
        condition: service_healthy
    restart: unless-stopped
    healthcheck:
      test: ["CMD", "wget", "-qO-", "http://localhost/health"]
      interval: 10s
      timeout: 5s
      retries: 3
      start_period: 5s

  # eXeLearning Instance 1
  exelearning-1:
    image: ghcr.io/exelearning/exelearning:${TAG:-latest}
    build: ../../
    restart: unless-stopped
    volumes:
      - exelearning-assets:/mnt/data:rw
    environment:
      # Application settings
      APP_ENV: prod
      APP_DEBUG: 0
      APP_SECRET: "${APP_SECRET:-ChangeThisToASecretForHADeployment}"
      APP_ONLINE_MODE: 1
      ONLINE_THEMES_INSTALL: ${ONLINE_THEMES_INSTALL:-0}

      # Database settings (PostgreSQL)
      DB_DRIVER: pdo_pgsql
      DB_HOST: postgres
      DB_PORT: 5432
      DB_NAME: "${DB_NAME:-exelearning}"
      DB_USER: "${DB_USER:-postgres}"
      DB_PASSWORD: "${DB_PASSWORD:-postgres}"
      DB_CHARSET: "${DB_CHARSET:-utf8}"
      DB_SERVER_VERSION: 18

      # Files directory (shared volume)
      FILES_DIR: "/mnt/data/"

      # Redis configuration for HA
      REDIS_HOST: redis
      REDIS_PORT: 6379

      # Authentication settings
      APP_AUTH_METHODS: "${APP_AUTH_METHODS:-password,guest}"
      AUTH_CREATE_USERS: "${AUTH_CREATE_USERS:-true}"

      # Admin user (created/updated when ADMIN_PASSWORD is set)
      ADMIN_EMAIL: "${ADMIN_EMAIL}"
      # ADMIN_PASSWORD: "${ADMIN_PASSWORD}"

      # JWT secret (MUST be same across all instances)
      API_JWT_SECRET: "${API_JWT_SECRET:-ChangeThisToASecretForHADeployment}"

    depends_on:
      postgres:
        condition: service_healthy
      redis:
        condition: service_healthy
    healthcheck:
      test: ["CMD", "sh", "-c", "wget -qO- http://localhost:${APP_PORT:-8080}/healthcheck"]
      interval: 30s
      timeout: 10s
      retries: 3
      start_period: 40s

  # eXeLearning Instance 2
  exelearning-2:
    image: ghcr.io/exelearning/exelearning:${TAG:-latest}
    build: ../../
    restart: unless-stopped
    volumes:
      - exelearning-assets:/mnt/data:rw
    environment:
      # Application settings
      APP_ENV: prod
      APP_DEBUG: 0
      APP_SECRET: "${APP_SECRET:-ChangeThisToASecretForHADeployment}"
      APP_ONLINE_MODE: 1

      # Database settings (PostgreSQL - same as instance 1)
      DB_DRIVER: pdo_pgsql
      DB_HOST: postgres
      DB_PORT: 5432
      DB_NAME: "${DB_NAME:-exelearning}"
      DB_USER: "${DB_USER:-postgres}"
      DB_PASSWORD: "${DB_PASSWORD:-postgres}"
      DB_CHARSET: "${DB_CHARSET:-utf8}"
      DB_SERVER_VERSION: 18

      # Files directory (shared volume)
      FILES_DIR: "/mnt/data/"

      # Redis configuration for HA
      REDIS_HOST: redis
      REDIS_PORT: 6379

      # Authentication settings
      APP_AUTH_METHODS: "${APP_AUTH_METHODS:-password,guest}"
      AUTH_CREATE_USERS: "${AUTH_CREATE_USERS:-true}"

      # Admin user (same credentials as instance 1, handled automatically by app)
      ADMIN_EMAIL: "${ADMIN_EMAIL}"
      # ADMIN_PASSWORD: "${ADMIN_PASSWORD}"

      # JWT secret (MUST be same across all instances)
      API_JWT_SECRET: "${API_JWT_SECRET:-ChangeThisToASecretForHADeployment}"

    depends_on:
      postgres:
        condition: service_healthy
      redis:
        condition: service_healthy
    healthcheck:
      test: ["CMD", "sh", "-c", "wget -qO- http://localhost:${APP_PORT:-8080}/healthcheck"]
      interval: 30s
      timeout: 10s
      retries: 3
      start_period: 40s

  # PostgreSQL Database
  postgres:
    image: postgres:18-alpine
    restart: unless-stopped
    environment:
      POSTGRES_PASSWORD: "${DB_PASSWORD:-postgres}"
      POSTGRES_USER: "${DB_USER:-postgres}"
      POSTGRES_DB: "${DB_NAME:-exelearning}"
    volumes:
      - postgres-data:/var/lib/postgresql
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U ${DB_USER:-postgres} -d ${DB_NAME:-exelearning}"]
      interval: 10s
      timeout: 5s
      retries: 5
      start_period: 10s

  # Redis for Yjs Synchronization
  redis:
    image: redis:alpine
    restart: unless-stopped
    command: redis-server --appendonly yes --maxmemory 256mb --maxmemory-policy allkeys-lru
    volumes:
      - redis-data:/data
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 10s
      timeout: 5s
      retries: 5
      start_period: 5s

volumes:
  exelearning-assets:
    # For production, consider using NFS or cloud storage driver
    # driver: local
    # driver_opts:
    #   type: nfs
    #   o: addr=nfs-server.example.com,rw
    #   device: ":/exports/exelearning"
  postgres-data:
  redis-data:

networks:
  default:
    driver: bridge