Immutable WordPress Example. Visit the following for further information: https://blog.duaneleem.com/immutable-wordpress-example/

.htaccess

# ================================================================================
#   Redirects uploads to production.
# ================================================================================
<IfModule mod_rewrite.c>
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteRule ^wp-content/uploads/(.*)$ https://www.someotherdomain.com/wp-content/uploads/$1 [R=301,NC,L]
</IfModule>

# ================================================================================
#   Docker WordPress
# ================================================================================
# BEGIN WordPress
<IfModule mod_rewrite.c>
  RewriteEngine On
  RewriteBase /
  RewriteRule ^index\.php$ - [L]
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteRule . /index.php [L]
</IfModule>
# END WordPress

docker-compose-mysql.yaml

## A general MySQL configuration.
version: '3.1'

services:
  main:
    image: mysql:5.6
    network_mode: bridge
    volumes:
      - db_data:/var/lib/mysql
    ports:
      - 3306:3306
    expose:
      - "3306"
    restart: always
    container_name: db-mysql-main
    environment:
      MYSQL_ROOT_PASSWORD: somesuperdupersecretpwd

volumes:
  db_data:

docker-compose-wordpress.yaml

## WordPress instance that connects to db-mysql-main MySQL
version: '3'

services:
  wtmain:
    image: wordpress:4.9.8-php5.6-apache
    network_mode: bridge
    volumes:
      - "/var/www/somedomain.com/sandbox/wp-content/themes:/var/www/html/wp-content/themes"
      - "/var/www/somedomain.com/sandbox/wp-content/plugins:/var/www/html/wp-content/plugins"
      - "/var/www/somedomain.com/sandbox/wp-content/uploads:/var/www/html/wp-content/uploads"
      - "/var/www/somedomain.com/sandbox/.htaccess:/var/www/html/.htaccess"
    ports:
      - "8101:80"
    restart: always
    container_name: wp-test
    external_links:
      - db-mysql-main:mysql
    environment:
      WORDPRESS_DB_NAME: wordpress
      WORDPRESS_DB_USER: usernamegoeshere
      WORDPRESS_DB_PASSWORD: somesuperdupersecretpwd
      WORDPRESS_TABLE_PREFIX: wp_
      WORDPRESS_CONFIG_EXTRA: |
        /* Fix site URL. */
        define("WP_HOME", "http://someotherdomain.com:8080");
        define("WP_SITEURL", "http://someotherdomain.com:8080");