symfony unable to create cache dir on docker

i make a docker-compose to my symfony application, it works, but it throw me a permissions error when the app try to create the cache directory:

this is my docker-compose file:

nginx:
      image: nginx:1.15-alpine
      restart: unless-stopped
      ports:
        - "8000:80"
      volumes:
        - .:/app:delegated
        - ./docker/nginx/nginx.conf:/etc/nginx/conf.d/default.conf:ro
      depends_on:
        - php

    php:
      build:
        context: .
        dockerfile: docker/php-fpm/Dockerfile
      restart: unless-stopped
      ports:
        - "9030:9001"
      volumes:
        - .:/app:delegated

and this is my php dockerfile:

FROM composer:1.8 AS vendor

COPY composer.json composer.lock /app/

RUN composer install 
     --ignore-platform-reqs 
        --no-interaction 
        --no-plugins 
        --no-scripts 
        --prefer-dist

FROM php:7-fpm-alpine3.8
WORKDIR /app
RUN docker-php-ext-install sockets mysqli mbstring bcmath pdo_mysql pdo
COPY . /var/www/html/app
COPY --from=vendor ./app/vendor/ /var/www/html/app/vendor/
COPY ./docker/php-fpm/php-ini-overrides.ini /etc/php/7.0/fpm/conf.d/99-overrides.ini

EXPOSE 80

this throw me this error when i enter to localhost:8000

Fatal error: Uncaught RuntimeException: Unable to create the cache directory (/app/app/cache/prod) in /app/app/bootstrap.php.cache:2725 Stack trace: #0 /app/app/bootstrap.php.cache(2686): SymfonyComponentHttpKernelKernel->buildContainer() #1 /app/app/bootstrap.php.cache(2465): SymfonyComponentHttpKernelKernel->initializeContainer() #2 /app/app/AppKernel.php(19): SymfonyComponentHttpKernelKernel->boot() #3 /app/app/bootstrap.php.cache(2496): AppKernel->boot() #4 /app/web/app.php(28): SymfonyComponentHttpKernelKernel->handle(Object(SymfonyComponentHttpFoundationRequest)) #5 {main} thrown in /app/app/bootstrap.php.cache on line 2725

how can i fix it?

Source: StackOverflow