gnu-social/DOCKER_INSTALL.md

Make sure to set the permissions of this folder to group and group 82, as that's what php-fpm uses

groupadd -g 82 www-data

useradd -u 82 -g 82 -r -s /usr/bin/nologin www-data

chown $USER:www-data social file public public/install.php public/index.php

chmod -R g=wrx social file public public/install.php public/index.php