If the web server is running as different user / group, change www-data
accordingly.
# add current user to www-data group.
sudo usermod -aG www-data USER
cd /path/to/laravel/repo
sudo chown -RUSER:www-data .
sudo find . -type f -exec chmod 664 {} \;
sudo find . -type d -exec chmod 775 {} \;
sudo chgrp -R www-data storage bootstrap/cache
sudo chmod -R ug+rwx storage bootstrap/cache
In case the permissions / ownerships are messed up, you can execute the scripts to reset.