Docker Compose configuration to run MySQL 5.6 and MySQL 5.7 on one instance. Create /var/lib/mysql56-data & /var/lib/mysql57-data with root as the owner of these directories before running docker-compose up -d

docker-compose.yml

version: '3'
services:
    mysql56:
        image: mysql:5.6
        restart: unless-stopped
        container_name: mysql56-container
        ports:
            - "127.0.0.1:3356:3306"
        environment:
            MYSQL_ROOT_PASSWORD: rootPassword
        volumes:
            - /var/lib/mysql56-data:/var/lib/mysql
            
    mysql57:
        image: mysql:5.7
        restart: unless-stopped
        container_name: mysql57-container
        ports:
            - "127.0.0.1:3357:3306"
        environment:
            MYSQL_ROOT_PASSWORD: rootPassword
        volumes:
            - /var/lib/mysql57-data:/var/lib/mysql