Run container as unprivileged www-data user and simplify entrypoint

- Remove root-only FPM user configuration from entrypoint.sh (moved to Dockerfile build time)
- Remove Redis session configuration from entrypoint.sh (handled by Symfony services)
- Remove cache directory permission adjustments (unnecessary with proper ownership)
- Set file ownership to www-data:www-data at build time using COPY --chown
- Create required directories and set ownership in single RUN layer
- Switch to www-data USER before CMD
- Remove PHP_FPM_USER, PHP_FPM_GROUP, SESSION_LIFETIME environment variables
- Add docker/ directory to .dockerignore

entrypoint.sh

@@ -16,23 +16,6 @@ else
   echo "we assume the database is ready";
 fi
 
-
-if [ $(id -u) = "0" ]; then
-  { \
-    echo "[www]"; \
-    echo ""; \
-    echo "user=${PHP_FPM_USER}"; \
-    echo "group=${PHP_FPM_GROUP}"; \
-  } > /usr/local/etc/php-fpm.d/zz-user.conf
-fi
-
-{ \
-    echo ""; \
-    echo "session.save_handler = redis" ; \
-    echo "session.save_path = \"tcp://${REDIS_HOST}:${REDIS_PORT}?db=10\"" ; \
-    echo "session.gc_maxlifetime = ${SESSION_LIFETIME}" ; \
-} >> /usr/local/etc/php/conf.d/custom.ini
-
 if [ "${APP_ENV}" = "prod" ]; then
   composer dump-env "${APP_ENV}"
   chmod +r /var/www/app/.env.local.php
@@ -48,8 +31,6 @@ fi
 if [ "${CLEAR_CACHE}" != "false" ]; then
   #prepare cache
   php /var/www/app/bin/console cache:clear --no-warmup
-  chgrp ${PHP_FPM_GROUP} /var/www/app/var/cache -R && chmod g+rw /var/www/app/var/cache -R
-  chgrp ${PHP_FPM_GROUP} /var/www/app/var/log   -R && chmod g+rw /var/www/app/var/log   -R
 fi
 
 exec "${@}"