Check out example codes for "docker-compose for yaml". It will help you in understanding the concepts better.

Code Example 1

version: "3"

services:
	frontend:
    	restart: always
        build:
        	context: .
            dockerfile: Dockerfile
        network_mode: host
        volume:
         - /path/to/volume

Code Example 2

docker-compose ps

Code Example 3

version: '3'

services:
   db:
     image: mysql:5.7
     volumes:
       - db_data:/var/lib/mysql
     restart: always
     environment:
       MYSQL_ROOT_PASSWORD: somewordpress
       MYSQL_DATABASE: wordpress
       MYSQL_USER: wordpress
       MYSQL_PASSWORD: wordpress

   wordpress:
     depends_on:
       - db
     image: wordpress:latest
     ports:
       - "8000:80"
     restart: always
     environment:
       WORDPRESS_DB_HOST: db:3306
       WORDPRESS_DB_USER: wordpress
       WORDPRESS_DB_PASSWORD: wordpress
volumes:
    db_data:

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