image: phpmyadmin
    ports:
      - 8080:80
    depends_on:
      - db
    environment:
      - PMA_HOST=db
volumes:
  db-data:
secrets:
  db-password:
    file: db/password.txt
```

Run the following command to run your application with Compose Watch.

```console
$ docker compose watch
```

Open a browser and verify that the application is running at [http://localhost:9000/hello.php](http://localhost:9000/hello.php).

Any changes to the application's source files on your local machine will now be
immediately reflected in the running container.

Open `hello.php` in an IDE or text editor and update the string `Hello, world!` to `Hello, Docker!`.

Save the changes to `hello.php` and then wait a few seconds for the application to sync. Refresh [http://localhost:9000/hello.php](http://localhost:9000/hello.php) in your browser and verify that the updated text appears.

Press `ctrl+c` in the terminal to stop Compose Watch. Run `docker compose down` in the terminal to stop the application.

## Create a development container

At this point, when you run your containerized application, Composer isn't installing the dev dependencies. While this small image is good for production, it lacks the tools and dependencies you may need when developing and it doesn't include the `tests` directory. You can use multi-stage builds to build stages for both development and production in the same Dockerfile. For more details, see [Multi-stage builds](/manuals/build/building/multi-stage.md).

In the `Dockerfile`, you'll need to update the following:

1. Split the `deps` staged into two stages. One stage for production
   (`prod-deps`) and one stage (`dev-deps`) to install development dependencies.
2. Create a common `base` stage.
3. Create a new `development` stage for development.
4. Update the `final` stage to copy dependencies from the new `prod-deps` stage.

The following is the `Dockerfile` before and after the changes.

{{< tabs >}}
{{< tab name="Before" >}}

```dockerfile
# syntax=docker/dockerfile:1

FROM composer:lts as deps
WORKDIR /app
RUN --mount=type=bind,source=composer.json,target=composer.json \
    --mount=type=bind,source=composer.lock,target=composer.lock \
    --mount=type=cache,target=/tmp/cache \
    composer install --no-dev --no-interaction

FROM php:8.2-apache as final
RUN docker-php-ext-install pdo pdo_mysql
RUN mv "$PHP_INI_DIR/php.ini-production" "$PHP_INI_DIR/php.ini"
COPY --from=deps app/vendor/ /var/www/html/vendor
COPY ./src /var/www/html
USER www-data
```

{{< /tab >}}
{{< tab name="After" >}}