| 1234567891011121314151617181920 | services:  backend:    ports:      - "${BACKEND_HOST:-0.0.0.0}:${BACKEND_PORT:-8080}:8080"    volumes:      - ./backend:/opt/app  frontend:    volumes:      - ./frontend:/opt/app  mongo:    ports:      - "${MONGO_HOST:-0.0.0.0}:${MONGO_PORT:-27017}:${MONGO_PORT:-27017}"  redis:    ports:      - "${REDIS_HOST:-0.0.0.0}:${REDIS_PORT:-6379}:6379"    volumes:      - ${REDIS_DATA_LOCATION:-./redis}:/data
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