How to sync Yosemite Photos library to Synology Diskstation?
I'm doing that with Phoshare.

I'm using automator for running an apple script when my iMac starts. This script calls phoshare to sync my events with the NAS.

The apple script look like:

cd /Applications/Phoshare-1.5.2.app/Contents/MacOS
./Phoshare \
  --export "/Volumes/photo/2015" \
  --iphoto "/Users/toto/Pictures/iPhoto Library.photolibrary" \
  -e ".*2015" \
  --foldertemplate "{mm}-{name}" \
  --nametemplate "{title}" \
  --captiontemplate "{description}" \
  -u -d -f -K --gps