Simple Docker WordPress Install (MariaDB)

.env

DB_USER="exampleuser"
DB_PASSWORD="examplepassword"
DB_NAME="wordpress_site"

docker-compose.yml

version: "3.1"
services:
  wordpress:
    image: wordpress
    restart: always
    ports:
      - 80
    environment:
      WORDPRESS_DB_HOST: database
      WORDPRESS_DB_USER: ${DB_USER?err}
      WORDPRESS_DB_PASSWORD: ${DB_PASSWORD?err}
      WORDPRESS_DB_NAME: ${DB_NAME?err}
    networks:
      - layer1
    volumes:
      - ./wordpress:/var/www/html
  database:
    image: mariadb
    restart: always
    environment:
      MARIADB_USER: ${DB_USER?err}
      MARIADB_PASSWORD: ${DB_PASSWORD?err}
      MARIADB_DATABASE: ${DB_NAME?err}
      MARIADB_RANDOM_ROOT_PASSWORD: yes
      MARIADB_ROOT_HOST: localhost
      MARIADB_AUTO_UPGRADE: yes
    networks:
      - layer1
    volumes:
      - database:/var/lib/mysql
networks:
  layer1:
    driver: bridge
volumes:
  database: