docker / mongo replicaSet

docker-compose.yml

version: '3.7'
services:
  dockerhost:
    image: qoomon/docker-host
    hostname: '${MONGO_HOST:?err}'
    container_name: '${MONGO_HOST:?err}'
    cap_add: ['NET_ADMIN', 'NET_RAW']
    restart: on-failure
  mongodb-primary:
    depends_on: [dockerhost]
    hostname: mongodb-primary
    build:
      context: .
      cache_from:
        - 'mongo:${MONGO_VERSION:?err}'
        - imz-mongodb
      dockerfile: Dockerfile
      args:
        - MONGO_VERSION=${MONGO_VERSION:?err}
    image: imz-mongodb
    expose:
      - 27017
    ports:
      - 27017:27017
    restart: always
    command: '--bind_ip 0.0.0.0 --setParameter disableJavaScriptJIT=false --keyFile /data/keyfile/keyfile --replSet ${MONGO_REPLICA_SET:?err}'
    environment:
      MONGO_INITDB_ROOT_USERNAME: '${MONGO_ROOT_USERNAME:?err}'
      MONGO_INITDB_ROOT_PASSWORD: '${MONGO_ROOT_PASSWORD:?err}'
      MONGO_INITDB_DATABASE: '${MONGO_AUTH_DATABASE:?err}'
    volumes:
      - /data/keyfile/
      - ./storage:/data
  mongodb-secondary:
    depends_on: [dockerhost]
    hostname: mongodb-secondary
    build:
      context: .
      cache_from:
        - 'mongo:${MONGO_VERSION:?err}'
        - imz-mongodb
      dockerfile: Dockerfile
      args:
        - MONGO_VERSION=${MONGO_VERSION:?err}
    image: imz-mongodb
    expose:
      - 27018
    ports:
      - 27018:27018
    restart: always
    command: '--bind_ip 0.0.0.0 --port 27018 --setParameter disableJavaScriptJIT=false --keyFile /data/keyfile/keyfile --replSet ${MONGO_REPLICA_SET:?err}'
  mongodb-arbiter:
    depends_on: [dockerhost]
    hostname: mongodb-arbiter
    build:
      context: .
      cache_from:
        - 'mongo:${MONGO_VERSION:?err}'
        - imz-mongodb
      dockerfile: Dockerfile
      args:
        - MONGO_VERSION=${MONGO_VERSION:?err}
    image: imz-mongodb
    expose:
      - 27019
    ports:
      - 27019:27019
    restart: always
    command: '--bind_ip 0.0.0.0 --port 27019 --setParameter disableJavaScriptJIT=false --keyFile /data/keyfile/keyfile --replSet ${MONGO_REPLICA_SET:?err}'
  mongodb-init_script:
    depends_on: [mongodb-primary, mongodb-secondary, mongodb-arbiter]
    image: 'mongo:${MONGO_VERSION:?err}'
    restart: 'no'
    entrypoint:
      - /bin/bash
      - -c
      - |
        sleep 10; \
        mongo --host ${MONGO_HOST:?err} --username ${MONGO_ROOT_USERNAME:?err} --password ${MONGO_ROOT_PASSWORD:?err} --authenticationDatabase ${MONGO_AUTH_DATABASE:?err} \
        --eval 'rs.initiate({ _id: "${MONGO_REPLICA_SET:?err}", members: [ { _id: 0, host: "${MONGO_HOST:?err}:27017" }, { _id: 1, host: "${MONGO_HOST:?err}:27018" }, { _id: 2, host: "${MONGO_HOST:?err}:27019", arbiterOnly: true } ] });'

Dockerfile

ARG  MONGO_VERSION
FROM mongo:${MONGO_VERSION}

RUN mkdir -p /data/keyfile
RUN openssl rand -base64 741 > /data/keyfile/keyfile
RUN chown -R mongodb:mongodb /data/keyfile
RUN chmod 600 /data/keyfile/keyfile

mkdir mongo
cd mongo
curl -L https://gist.github.com/medfreeman/9fe30c43706420c6df19a14ac98a2458/download | tar -xvz --strip-components=1
MONGO_HOST=my_hostname MONGO_VERSION=4.2 MONGO_REPLICA_SET=rs0 MONGO_ROOT_USERNAME=mongoadmin MONGO_ROOT_PASSWORD=admin MONGO_AUTH_DATABASE=admin docker-compose up -d dockerhost mongodb-primary mongodb-secondary mongodb-arbiter mongodb-init_script

Then make sure your hostname is resolvable on you host / client machines.