How to fix the access denied permission for files created inside a docker container from the host in a Laravel application?

Question

I tried different ways so far and saw similar questions in Stackoverflow but none worked. The problem is, that when I create a file inside the docker container, I can't edit it inside the host machine.

The project is a Laravel application with the following docker-compose file for the php service and its docker file.

...
services:
  php:
    build:
      context: ./dockerfiles
      dockerfile: php8.1.Dockerfile
    container_name: "php"
    restart: unless-stopped
    tty: true
    networks:
      - medyar_network
    volumes:
      - .:/var/www/html
    ports:
      - "${MEDYAR_PHP_PORT}:9000"
 ...

and Dockerfile

    FROM php:8.1-fpm-alpine
    RUN docker-php-ext-install  pdo pdo_mysql exif
    RUN apk add --no-cache pcre-dev $PHPIZE_DEPS \
            && pecl install redis \
            && docker-php-ext-enable redis.so
    
    RUN curl -s https://getcomposer.org/installer | php -- --install-dir=/usr/bin/ --filename=composer
    RUN alias composer='php /usr/bin/composer'
    RUN chmod -R 755 /var/www
    RUN chown -R www-data:www-data /var/www

Most of the websites suggest adding the last two lines to the Dockerfile to fix the permission, however, it doesn't work. I would appreciate it if you let me know how to fix this.

Answer 1

Well, thanks to the Fixing permissions issues with Docker Compose and PHP article, the problem is solved. I added the following lines to the .env file:

UID=1000
GID=1000

which is obtained by commands

id -i
id -g

Next add the following arguments to the docker-compose file

user_php:
  build:
    context: ./dockerfiles
    dockerfile: php8.1.Dockerfile
    args:
      uid: "${UID-1000}"
      gid: "${GID-1000}"

and then modify the php8.1.Dockerfile as follows

FROM php:8.1-fpm-alpine
ARG uid
ARG gid

RUN addgroup -g ${gid} --system laravel
RUN adduser -G laravel --system -D -s /bin/sh -u ${uid} laravel
RUN sed -i "s/user = www-data/user = laravel/g" /usr/local/etc/php-fpm.d/www.conf
RUN sed -i "s/group = www-data/group = laravel/g" /usr/local/etc/php-fpm.d/www.conf

RUN apk add libpng-dev libzip-dev zip
RUN docker-php-ext-install  pdo pdo_mysql gd zip
RUN apk add --no-cache pcre-dev $PHPIZE_DEPS \
        && pecl install redis \
        && docker-php-ext-enable redis.so

RUN curl -s https://getcomposer.org/installer | php -- --install-dir=/usr/bin/ --filename=composer
RUN alias composer='php /usr/bin/composer'
RUN chmod -R 755 /var/www
USER laravel

It creates a user and group with the given uid and gid. Then modify the user that PHP is actually running on in the container and php.ini configuration.