Overview of Docker Compose

Get started with Docker Compose and run multiple containers

---

So far we have seen how to run single container from command line at once.

In this episode, we will see how to run multiple containers at once, through single command.

Overview of Docker Compose

• Tool for defining and running multi-container Docker applications.
• YAML file (docker-compose.yaml) defines the application’s services configurations.
• Single command to start and stop all services.

Running Dynamic application without volume

In this section, we will run our Dynamic application using Docker Compose without having any Volume.

• Our docker-compose.yaml will looks like below:

  version: '3'
  services:
    my-app:
      image: docker-node-app
      ports:
        - 3000:3000
    mongodb:
      image: mongo
      ports:
        - 27017:27017
      environment:
        - MONGO_INITDB_ROOT_USERNAME=admin
        - MONGO_INITDB_ROOT_PASSWORD=password
    mongo-express:
      image: mongo-express:0.54 # latest is having issue
      ports:
        - 8080:8081
      environment:
        - ME_CONFIG_MONGODB_ADMINUSERNAME=admin
        - ME_CONFIG_MONGODB_ADMINPASSWORD=password
        - ME_CONFIG_MONGODB_SERVER=mongodb
  

• Start the application using following command:

  $ docker-compose up # you can use -d in detach mode
  

  NOTE: Note that the application image docker-node-app has to be build before running docker-compose up command.

  Instructor

  Explain the docker-compose.yaml file. Show how to create data in this running application. Also, discuss the data persistance issue.

Running Dynamic application with volume

Now, we will run our Dynamic application using Docker Compose having Volume.

• Our docker-compose.yaml will looks like below:

  version: '3'
  services:
    my-app:
      image: docker-node-app
      ports:
        - 3000:3000
    mongodb:
      image: mongo
      ports:
        - 27017:27017
      environment:
        - MONGO_INITDB_ROOT_USERNAME=admin
        - MONGO_INITDB_ROOT_PASSWORD=password
      volumes:
        - mongo-data:/data/db
    mongo-express:
      image: mongo-express:0.54 # latest is having issue
      ports:
        - 8081:8081
      environment:
        - ME_CONFIG_MONGODB_ADMINUSERNAME=admin
        - ME_CONFIG_MONGODB_ADMINPASSWORD=password
        - ME_CONFIG_MONGODB_SERVER=mongodb
  volumes:
    mongo-data:
      driver: local
  

  Instructor

  Show the demo of data persistance issue.