1. Multi container apps - quan1997ap/Backend-app-note GitHub Wiki

Muc dich

There’s a good chance you’d have to scale APIs and front-ends differently than databases.
Separate containers let you version and update versions in isolation.
While you may use a container for the database locally, you may want to use a managed service for the database in production. You don’t want to ship your database engine with your app then.
Running multiple processes will require a process manager (the container only starts one process), which adds complexity to container startup/shutdown.

Container networking

1. Install Docker Compose

https://docs.docker.com/compose/install/linux/

After installation, you should be able to run the following and see version information.

   docker compose version

2. Create the Compose file

Step 1: At the root of the /getting-started/app folder, create a file named docker-compose.yml.

Step 2: Define the app service : https://docs.docker.com/get-started/08_using_compose/

services:
  app:
    image: node:18-alpine
    command: sh -c "yarn install && yarn run dev"
    ports:
      - 127.0.0.1:3000:3000
    working_dir: /app
    volumes:
      - ./:/app
    environment:
      MYSQL_HOST: mysql
      MYSQL_USER: root
      MYSQL_PASSWORD: secret
      MYSQL_DB: todos

  mysql:
    image: mysql:8.0
    volumes:
      - todo-mysql-data:/var/lib/mysql
    environment:
      MYSQL_ROOT_PASSWORD: secret
      MYSQL_DATABASE: todos

volumes:
  todo-mysql-data:

services: Danh sach cac service se dinh nghia (The name will automatically become a network alias, which will be useful when defining our MySQL service )
app: Ten service con
image + command
ports
- Sort + Long synctax : https://docs.docker.com/compose/compose-file/05-services/#long-syntax-3
```
  127.0.0.1:3000:3000
```
volumes

3. Run the application stack

3.1 Make sure no other copies of the app/db are running first (docker ps and docker rm -f ).
3.2 Start up the application stack We’ll add the -d flag to run everything in the background.

docker compose up -d

3.3 View log

docker compose logs -f

or - log of service app

docker compose logs -f app

4. Tear it all down

   docker compose down

If you want to remove the volumes ( add the --volumes flag )

   docker compose down --volumes