version: "3"
services:
db:
container_name: db
image: mysql
ports:
- "3306:3306"
environment:
- MYSQL_ROOT_PASSWORD=mysql
- MYSQL_DATABASE=db
volumes:
- /home/user/db/mysql/data:/var/lib/mysql
- /home/user/db/mysql/init:/docker-entrypoint-initdb.d/:ro
Прописываете по аналогии с первым доменом