version: '2.2'
services:
    zoo1:
        image: zookeeper:3.4.12
        restart: always
        environment:
            ZOO_TICK_TIME: 500
            ZOO_MY_ID: 1
            ZOO_SERVERS: server.1=zoo1:2888:3888 server.2=zoo2:2888:3888 server.3=zoo3:2888:3888

    zoo2:
        image: zookeeper:3.4.12
        restart: always
        environment:
            ZOO_TICK_TIME: 500
            ZOO_MY_ID: 2
            ZOO_SERVERS: server.1=zoo1:2888:3888 server.2=zoo2:2888:3888 server.3=zoo3:2888:3888

    zoo3:
        image: zookeeper:3.4.12
        restart: always
        environment:
            ZOO_TICK_TIME: 500
            ZOO_MY_ID: 3
            ZOO_SERVERS: server.1=zoo1:2888:3888 server.2=zoo2:2888:3888 server.3=zoo3:2888:3888