@huber70
OK!
Questions:
1 - you can use docker?
2 - have you visited
https://bpatrik.github.io/pigallery2/ ? I do not think its suitable for 10.000+ photo's, but its usable for using with your friends.
3 - does your Pi have a cooling fan? Importing a few hundred pictures is quite a task for the Pi, and it will run hot. I do not want to think about a few thousand ........