The thumbnails service provides methods to generate thumbnails for various files. It retrieves the sources at the location where the user files are stored and saves the tumbnails at the location where system files are stored. Those locations have defaults but can be manually defined via environment variables. The relevant environment variables are:

OCIS_BASE_DATA_PATH which will contain system relevant data and
STORAGE_USERS_OCIS_ROOT which will contain the user source data.
THUMBNAILS_FILESYSTEMSTORAGE_ROOT used if thumnails should be separated from system files.

For details and defaults see the documentation.

Thumbnails can be generated for the following file types:

png
jpg
gif
tiff
bmp
txt

Thumbnails can either be generated as png, jpg or gif files, various resolutions can be defined via THUMBNAILS_RESOLUTIONS.

NOTE

Since source files need to be loaded into memory when generating thumbnails, large source files could potentially crash this service if there is insufficient memory available. For bigger instances, this service can be dedicated to own servers with more memory when using container orchestration deployment methods.