datagrepper is almost ready in staging. I just need to update the documentation and cut another release.
You can test it if you "yum install httpie" and then run:
http --verify no get https://apps.stg.fedoraproject.org/datagrepper/raw/ delta==172800
This is a request for a production box to do it for reals (datagrepper01.phx2.fedoraproject.org).
The datagrepper01 and 02 instances are all setup now.
There's some very odd problem with the datagrepper::app module in puppet, so it's disabled on them right now.
Please do enable it and test them out, they should be otherwise ready to go.
We're good to go at https://apps.fedoraproject.org/datagrepper/