Docker Compose is a tool for defining and running multi-container Docker applications. It uses YAML files to configure the application's services and performs the creation and start-up process of all the containers with a single command. The docker-compose CLI utility allows users to run commands on multiple containers at once, for example, building images, scaling containers, running containers that were stopped, and more. The docker-compose.yml file is used to define an application's services and includes various configuration options.

docker-compose.yml edit

# Creates a three-container application based on Express, MariaDB, MongoDB, and Redis.
# MariaDB is used as a drop-in replacement for MySQL with a commitment to remaining open source.
#
# References:
#   https://en.wikiversity.org/wiki/Docker/Express
#   https://en.wikiversity.org/wiki/Docker/MySQL
#   https://en.wikiversity.org/wiki/Docker/MongoDB
#   https://en.wikiversity.org/wiki/Docker/Redis
#   https://en.wikiversity.org/wiki/Server-Side_Scripting

version: "2"
services:
  express-server:
    container_name: express-server
    restart: always
    build: .
    ports:
      - "3000:3000"
  mariadb-server:
    container_name: mariadb-server
    image: mariadb
    ports:
      - "3306:3306"
  mongo-server:
    container_name: mongo-server
    image: mongo
    ports:
      - "27017:27017"
  redis-server:
    container_name: redis-server
    image: redis
    ports:
      - "6379:6379"

Try It edit

Online Free edit

  1. Use Play with Docker. Create an account and/or log in.
  2. Start an interactive session and add a new instance.
  3. In the terminal window, enter the following commands:
    • touch docker-compose.yml
    • touch Dockerfile
    • touch app.js
  4. Use the Editor button to edit the files and save the contents into each respective file. Use the docker-compose.yml file above and the Dockerfile and app.js files from Docker/Express.
  5. Run the following commands:
    • docker-compose up
  6. In the top window, select the Open Port button and enter 3000 to connect to the running server.

On Your Own System edit

  1. Install Docker Desktop or the Docker Engine.
  2. Save the file above and from Docker/Express into a new Docker Express folder:
    • docker-compose.yml
    • Dockerfile
    • app.js
  3. At a command prompt, change to the Docker Express folder and then run the following command:
    • docker-compose up
  4. Open a web browser to connect to the running server:

See Also edit