Run farmOS Docker containers as the www-data user. Fixes farmOS#582

docker/Dockerfile

@@ -65,3 +65,6 @@ RUN mkdir /var/farmOS \
 COPY --chown=www-data docker-entrypoint.sh /usr/local/bin/
 ENTRYPOINT ["docker-entrypoint.sh"]
 CMD ["apache2-foreground"]
+
+# Run as the www-data user.
+USER www-data

docker/dev/Dockerfile

@@ -7,6 +7,9 @@ ARG FARMOS_VERSION=2.x
 ARG PROJECT_REPO=https://github.com/farmOS/composer-project.git
 ARG PROJECT_VERSION=2.x
 
+# Change to the root user for system-level changes.
+USER root
+
 # Install and enable XDebug extension.
 RUN yes | pecl install xdebug \
   && docker-php-ext-enable xdebug
@@ -53,11 +56,14 @@ RUN cp -p /var/farmOS/web/core/phpunit.xml.dist /var/farmOS/phpunit.xml \
   && sed -i 's|  </php>|    <env name="SYMFONY_DEPRECATIONS_HELPER" value="quiet[]=indirect"/>'"\n"'  </php>|g' /var/farmOS/phpunit.xml \
   && mkdir -p /var/farmOS/web/sites/simpletest/browser_output
 
-# Change back to the root user.
+# Change to the root user.
 USER root
 
 # Copy the farmOS codebase into /opt/drupal.
 RUN rm -r /opt/drupal && cp -rp /var/farmOS /opt/drupal
 
 # Create a Composer config directory for the www-data user.
 RUN mkdir /var/www/.composer && chown www-data:www-data /var/www/.composer
+
+# Run as the www-data user.
+USER www-data