[StackOverflow/docker] Setting up a custom Wordpress Theme inside a docker compose, gets deleted when WP is updated

### ROOT CAUSE The custom WordPress theme is being deleted during WordPress updates because the Docker volume for the WordPress data (including themes) is either not properly persisted or not mounted from the host. When the container is recreated during an update, data stored in container-specific volumes is lost unless explicitly persisted. ### CODE FIX Ensure the WordPress data directory is mounted from the host by modifying the `docker-compose.yml` file to use a bind mount for the `wp-content` directory. This preserves custom themes and plugins. ```yaml services: wordpress: image: wordpress:latest volumes: # Mount the host's wp-content directory to preserve themes/plugins - /path/to/host/wordpress:/var/www/html # ... other configurations ... ``` Replace `/path/to/host/wordpress` with the actual host directory path. This ensures the theme persists across container restarts and updates. If using a named volume, explicitly define it to avoid data loss: ```yaml volumes: wordpress_data: driver: local bind: /path/to/host/wordpress ``` Then reference it in the service: ```yaml wordpress: volumes: - wordpress_data:/var/www/html ```