For me, it would be likely useful to have the possibility to mount a docker volume with the custom fonts i need and have them automatically available in LOOL. AFAIK it needs a rescan command after adding new fonts (?)
Worked a bit on this, the following seems to be working: - copy your fonts to /usr/share/fonts/lool (make sure not to make subdirectories); - run fc-cache -fv; - mount /usr/share/fonts/lool in read-only to /usr/share/fonts/lool and /opt/lool/systemplate/usr/share/fonts/lool of the container. Need to better document this.
https://wiki.documentfoundation.org/Development/LibreOffice_Online#Installing_custom_fonts