Duplicity for Docker
This is a very basic Docker image with Duplicity and Dropbox & OAuth2 support (from Ubuntu PPA). You can simply create your app at dropbox.com/developers, generate auth token, create folder "backups" inside the "app folder" and run the image bind-mounting /files/to/backup:
docker run --rm -h duply -v /files/to/backup:/source -v duply:/root \
-e DPBX_ACCESS_TOKEN="" \
-e PASSPHRASE="" \
duplicity full /source dpbx:///backups
This container is just a wrapper for duplicity so any duplicity command is supported. With the example command metadata is stored in "duply" Docker volume (and then reused unless run with --rm) and backup sent to "backups" Dropbox folder. Do not forget to set "-h duply" parameter, otherwise pass --allow-source-mismatch argument on the next run.