I have installed piwigo in a docker container using portainer. I had no problem with mariadb but I am confused by the volume/bind mount to use in piwigo.
Before creating the piwigo container, I created a volume called piwigo_data. Then, when creating the piwigo container when I had to specify volumes, I selected volume (not bind) and inserted /config and piwigo_data. I then created the container. This worked but I noticed a bind mount (called a volume) was listed in the volumes of portainer. I installed piwigo and added a few photos. I discovered they had been put in /config/www/gallery/upload/2020/10/01/ (today's date)
I deleted the piwigo container and the volume and bind mount and created a new volume called piwigo_photos. I then created the piwigo container again but this time selected an additional volume entry /pictures and piwigo_photos. When I created the container I had both the volumes listed in portainer.
My confusion is why do I need the extra volume or bind mount if it has nothing in it? Secondly, why does portainer call a bind mount a volume?