It uses the vnstat database (just takes the JSON output to make the graphs).
go forth and break things. (or just play around with it and have fun)Known issues:
#1) There is an issue with the stacked bar graph. Documented here: https://github.com/novus/nvd3/issues/341#issuecomment-222370991
#2) If you have vnstat already running it will most likely override your options and also install the new database files in a different location than where yours currently are. This scenario is likely to produce the most edge cases.
#3) The start day defaults to 1 and is stored in the vnstat config file at the time of saving, but I don't have a way to get it back out of the config currently, so it shows up as blank. [fixed] #4) Which ties into number four, there isn't a way to save the graph options at this time. [fixed]
#5) The cron job that grabs the data runs every 5 minutes and the interval isn't documented at this time. [fix pending]
#6a) units should be in KiB/MiB/etc and the Y axis label needs to be changed to reflect totals not speed. [fixed] #6b) y axis tickmarks need custom formatting. [fixed] #7) lists PHP as a dependency when it doesn't need to. [fixed] #8) Top 10 Days only works when one interface is selected. I need to throw an error if multiple interfaces are selected. [fixed]
#9a) NanoBSD image is untested at this time, but should work. Data loss after a reboot needs to also be tested (actually, I may be able to tie the data into backups).
#9b) vnStat databases aren't being backed up.
#10a) Some interfaces are showing up blank. [fixed] #10b) It looks like vnStat doesn't support virtual and aliased interfaces, so not all interfaces will show up. [not entirely true] #11) match graph legend to interface names [fixed]
#12) the sortable table doesn't work after you update the graph or change the time period.
#13) looks like crap on mobile
#14) package needs to remove cron/config on uninstall