docker-compose.yml

version: '3.8'

services:
  # ⚠️ WARNING: DO NOT SCALE THIS SERVICE ⚠️
  #
  # This service runs database migrations on startup. Running multiple
  # instances simultaneously will cause race conditions and potential
  # data corruption.
  #
  # DO NOT RUN: docker-compose up --scale tome=3
  #
  # While the migration system has locking to prevent concurrent execution,
  # SQLite's file-based locking may not be reliable across all volume
  # mount types (especially network mounts like NFS).
  #
  # For high availability:
  # - Use blue-green deployment strategy
  # - Run migrations as a separate step before deployment
  # - Use a single instance with proper health checks
  #
  tome:
    build: .
    ports:
      - "3000:3000"
    environment:
      - NODE_ENV=production
      - CALIBRE_DB_PATH=/calibre/metadata.db
      # PUID/PGID: Customize user/group ID to match your host system
      # This eliminates permission issues with mounted volumes
      # Default: 1001:1001 (if not specified)
      # Common values:
      #   - Linux first user: 1000:1000
      #   - NAS systems: varies (run 'id' on your system)
      #   - From issue #237: 1001:100
      # Uncomment and set to your user's UID/GID:
      # - PUID=1000
      # - PGID=1000
    volumes:
      # Persist SQLite database
      # Permissions are automatically fixed on container startup
      # This includes /app/data and /app/.next for cache writes
      # No manual chown required!
      - tome-data:/app/data
      # Mount your Calibre library (read-write for rating sync)
      # Replace with your actual Calibre library path
      - ./calibre-library:/calibre
    restart: unless-stopped

volumes:
  tome-data:
    driver: local
    # Permissions are automatically managed by the container
    # The entrypoint sets ownership of /app/data and /app/.next to match PUID/PGID on startup