linuxserver.io made an rdesktop-web based docker image of DigiKam[0], so I guess it could be "upgraded" to self-hosted. I'd be tempted by the potential of setting up various digikams as a service for my various users (the member of my family), where each instance could share some but not all photo folders with others.

[0] https://github.com/linuxserver/docker-digikam