.env

SITE_FILES=./data/site
DB_FILES=./data/db

# Other variables are probably not relevant for volumes

docker-compose.local.yml

version: '3'

services:
  boilerplate-db:
    container_name: ${CONTAINER_DB_NAME}
    image: ${DB_IMAGE:-mariadb}:${DB_VERSION:-latest}
    restart: unless-stopped
    volumes:
      - ${DB_FILES}:/var/lib/mysql
    environment:
      MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD}
      MYSQL_DATABASE: ${MYSQL_DATABASE}
      MYSQL_USER: ${MYSQL_USER}
      MYSQL_PASSWORD: ${MYSQL_PASSWORD}
    networks:
      wp:

  wordpress:
    build: .
    container_name: ${CONTAINER_SITE_NAME}
    restart: unless-stopped
    ports:
      - "80:80"
    volumes:
      - ${SITE_FILES}/uploads:/var/www/html/wp-content/uploads
      - "./themes/anyday:/var/www/html/wp-content/themes/anyday/"
      - "./plugins:/var/www/html/wp-content/plugins"
      - "./mu-plugins:/var/www/html/wp-content/mu-plugins"
      - ./conf.d/php.ini:/usr/local/etc/php/conf.d/php.ini
    environment:
      WORDPRESS_DB_HOST: ${CONTAINER_DB_NAME}:3306
      WORDPRESS_DB_NAME: ${MYSQL_DATABASE}
      WORDPRESS_DB_USER: ${MYSQL_USER}
      WORDPRESS_DB_PASSWORD: ${MYSQL_PASSWORD}
      WORDPRESS_TABLE_PREFIX: ${WORDPRESS_TABLE_PREFIX}
    logging:
      options:
        max-size: ${LOGGING_OPTIONS_MAX_SIZE:-200k}
    networks:
      wp:                            

networks:
  wp:

Dockerfile

FROM wordpress:latest

COPY plugins /var/www/html/wp-content/plugins
COPY mu-plugins /var/www/html/wp-content/mu-plugins
COPY themes/anyday /var/www/html/wp-content/themes/anyday

php.ini

file_uploads=On
memory_limit=64M
upload_max_filesize=64M
post_max_size=64M
max_execution_time=600
expose_php=Off