Docker container that serves a dead-simple HTTP endpoint (using Sinatra) with images in a directory (my usecase is to serve them in descending modified_time order).
Useful for seamlessly integrating with the Adobe Lightroom's "publish to directory" feature if you have a file synchronization mechanism (like syncthing) between your personal computer and a web server.
docker run --publish="4567:4567" --volume="~/Pictures/synced-photos/:/pictures" -e "PHOTO_DIR=/pictures" hkdsun/photo_dir