version: '2.3'
services:
    postgres2:
        image: postgres
        restart: always
        environment:
            POSTGRES_PASSWORD: mysecretpassword
        ports:
            - 5421:5432
    postgres3:
        image: postgres
        restart: always
        environment:
            POSTGRES_PASSWORD: mysecretpassword
        ports:
            - 5441:5432
    postgres4:
        image: postgres
        restart: always
        environment:
            POSTGRES_PASSWORD: mysecretpassword
        ports:
            - 5461:5432