docker-compose.yml

version: '3'

# https://docs.docker.com/compose/compose-file/

# Notes:

# EXPOSE is used to expose ports without publishing them to the host machine — 
# they’ll only be accessible to linked services on the same network.
# The EXPOSE instruction does not actually publish the port. 
# It functions as a type of documentation between the person who builds the image and the person who runs the container, about which ports are intended to be published.

# PORTS is used to publish ports to a host. 
# You can either use a short syntax, or give a more detailed configuration.
# Either specify both ports (HOST:CONTAINER), or just the container port (an random, temporory host port is chosen).

services:

  mongo:
    image: mongo
    restart: always
    ports:
      - "27017:27017"
    # volumes:
    #   - /data/db:/var/lib/docker/volumes/<volume-name>
    environment:
      MONGO_INITDB_ROOT_USERNAME: ""
      MONGO_INITDB_ROOT_PASSWORD: ""

  mongo-express:
    image: mongo-express
    restart: always
    ports: 
      - "8081:8081"
    depends_on:
      - mongo
    environment:
      ME_CONFIG_MONGODB_SERVER: "mongo"
      ME_CONFIG_MONGODB_PORT: 27017
      ME_CONFIG_MONGODB_ENABLE_ADMIN: "true"
      ME_CONFIG_MONGODB_ADMINUSERNAME: ""
      ME_CONFIG_MONGODB_ADMINPASSWORD: ""

  zookeeper:
    image: wurstmeister/zookeeper
    ports:
      - "2181"
      
  kafka:
    image: wurstmeister/kafka
    depends_on:
      - zookeeper
    ports:
      - "9092:9092"
    environment:
      KAFKA_ADVERTISED_HOST_NAME: kafka # use localhost for single broker
      KAFKA_ZOOKEEPER_CONNECT: zookeeper:2181
      KAFKA_CREATE_TOPICS: "topicname:1:1"
    # volumes:
    #   - /var/run/docker.sock:/var/run/docker.sock

  application:
    build: ./application
    restart: on-failure
    ports:
      - "80"
    depends_on:
      - mongo
      - kafka